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Dive into the research topics where Michael Yaron is active.

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Featured researches published by Michael Yaron.


Clinical Infectious Diseases | 2002

Immunogenicity and safety of pneumococcal vaccination in patients with rheumatoid arthritis or systemic lupus erythematosus.

Ori Elkayam; Daphna Paran; Dan Caspi; Irena Litinsky; Michael Yaron; Darlene Charboneau; Jeffrey B. Rubins

Prevention of bacterial infection, which is a leading cause of morbidity in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), is a priority. However, the safety and immunogenicity of the pneumococcal vaccine in such patients remain controversial. We evaluated the currently available pneumococcal vaccine in patients with RA or SLE. Pneumococcal vaccination was not associated with an appreciable deterioration in any clinical or laboratory measure of disease activity in either group. One month after vaccination, patients in both groups had significant increases in geometric mean concentrations of pneumococcal polysaccharide-specific IgG to all 7 serotypes tested, as did control subjects. However, 14 (33.3%) of 42 patients with RA and 5 (20.8%) of 24 patients with SLE responded either to none or to only 1 of the 7 polysaccharides. Pneumococcal vaccination is generally safe and immunogenic in patients with RA or SLE, but a subset of patients may remain unprotected by the currently available vaccine.


Rheumatology International | 1995

Spa therapy for gonarthrosis: a prospective study

Irena Wigler; Ori Elkayam; Daphna Paran; Michael Yaron

The objective of this study was to evaluate the effect of spa therapy on clinical parameters of patients with gonarthrosis. Patients with gonarthrosis (n=33) underwent a 2-week spa therapy using three treatment regimes and a 20-week follow-up as follows: group I (n=11) had mineral water baths and hot native mineral mud packs, group II (n=12) had mineral water baths and rinsed mineral-free mud packs and group III (n=10) had tap water baths and mineral-free mud packs. The patients and the assessing rheumatologist were blinded to the difference in the treatment protocols. A significant improvement in the index of severity of the knee (ISK), as well as night pain scores, was achieved in group I. Improvement in physical findings and a reduction in pain ratings on a visual analogue scale (VAS) did not reach statistical significance. Analgesic consumption was significantly decreased in both groups I and III for up to 12 weeks. Global improvement assessed by patients and physician was observed in all three groups up to 16 weeks but persisted to the end of the follow-up period in group I only. Patients with gonarthrosis seemed to benefit from spa therapy under all three regimes. However, for two parameters (night pain and ISK) the combination of mineral water baths and mud packs (group I) appeared to be superior.


Osteoarthritis and Cartilage | 2003

The effects of Zintona EC (a ginger extract) on symptomatic gonarthritis

Irena Wigler; I Grotto; Dan Caspi; Michael Yaron

OBJECTIVEnEvaluation of the effect of a ginger extract (Zintona EC) on patients suffering from gonarthritis.nnnMATERIAL AND METHODSnTwenty-nine patients (6 men and 23 women) with symptomatic gonarthritis (ACR criteria), in the age range 42-85 years, were included after randomization in a double blind, placebo controlled, crossover study of 6 months duration. The treatment group was given a ginger extract (250 mg of Zingiberis Rhizoma per capsule, qid), while the placebo group received the same number of identical looking capsules per day. The crossover occurred after 3 months of therapy. Results were evaluated by a 100mm visual analog scale (VAS) of pain on movement and of handicap.nnnRESULTSnEight patients dropped out because of inefficacy, three from group 1 (ginger extract first) and five from group 2 (placebo first). One patient from group 1 and one from group 2 dropped out because of heartburn (while they were on ginger extract). Twenty patients completed the study period of 24 weeks and 19 that of 48 weeks follow-up. By the end of 24 weeks there was a highly statistically significant difference between the VAS of pain and handicap of the two groups (P<0.001). However, at crossover both groups showed a statistically significant decrease in VAS of pain on movement and of handicap, but the differences between the groups did not reach statistical significance.nnnCONCLUSIONSnZintona EC was as effective as placebo during the first 3 months of the study, but at the end of 6 months, 3 months after crossover, the ginger extract group showed a significant superiority over the placebo group.


Clinical Rheumatology | 2000

Psoriatic Arthritis: Interrelationships between Skin and Joint Manifestations Related to Onset, Course and Distribution

Ori Elkayam; J. Ophir; Michael Yaron; Dan Caspi

Abstract: To assess the relationships between skin and joint disease, 70 patients with psoriatic arthritis were consecutively evaluated. Data were obtained regarding age, sex, duration of disease, age at onset, and flares of both skin and joint disease. Rheumatological assessment included morning stiffness, number of swollen, tender and deformed joints, involvement of distal interphalangeal joints (DIP), presence of dactylitis, Achilles tendinitis, and clinical lumbar and cervical involvement. Skin assessment included recording of the distribution of skin lesions and nail involvement, and grading of psoriasis severity using the PASI. The scalp was the most frequently involved site. Significant correlation was found between the PASI score and the number of deformed joints and Schober’s test. The scalp score was found to correlate with the number of swollen joints, deformed joints, sausage finger and DIP involvement. Synchronous flares of skin and joint were significantly more frequent in the patients with onset of skin and joint diseases within the same year. Likewise, these patients showed a highly significant association between the PASI score and the number of tender, swollen and deformed joints, Schober’s test and cervical involvement, whereas no such associations were found among patients with separate onset of skin and joint diseases.


Rheumatology International | 2000

Serum levels of IL-10, IL-6, IL-1ra, and sIL-2R in patients with psoriatic arthritis

Ori Elkayam; I. Yaron; Idit Shirazi; Michael Yaron; Dan Caspi

Abstract Our objective was to evaluate the levels of interleukin-6 (IL-6), soluble receptors of IL-2 (sIL-2R), IL-10, and IL-1 receptor antagonists (IL-1ra) in the serum of patients with psoriatic arthritis (PsA) and to assess the correlation between these levels and parameters of clinical activity of skin and joint disease.In total, 34 patients with PsA and ten healthy volunteers participated in the study. Assessment of joint disease included duration of morning stiffness, number of tender and swollen joints, right and left grip, the presence of inflammatory spinal back pain, and Schober test. Current severity of skin disease was graded according to the psoriasis area and severity index (PASI). Erythrocyte sedimentation rate (ESR) was determined as a marker of disease activity. Serum levels of IL-6, sIL-2R, IL-1ra, and IL-10 were measured by an enzyme immunoassay kit.Significantly higher serum levels of IL-6, sIL-2R, IL-1ra, and IL-10 were found in patients with PsA in comparison with healthy volunteers. A statistically significant correlation was found between levels of sIL-2R and PASI, whereas no association was found with clinical parameters of joint severity. Levels of IL-1ra correlated with the number of tender and swollen joints. No correlation was found between levels of IL-6, IL-10, and clinical parameters of skin and joint severity. In the group of patients with PsA, serum levels of sIL-2R clearly correlated with severity of skin disease, whereas levels of IL-1ra were associated with joint severity.


The American Journal of Medicine | 2003

Early and late effects of low-dose aspirin on renal function in elderly patients

Refael Segal; Emilia Lubart; Arthur Leibovitz; Matitiahu Berkovitch; Beni Habot; Michael Yaron; Dan Caspi

BACKGROUNDnAlthough low-dose aspirin is used by many elderly patients, monitoring of renal function is currently not recommended. We recently reported transient retention of uric acid and creatinine caused by aspirin in doses of 75 to 325 mg/d. We therefore evaluated the renal effects of aspirin (100 mg/d), including post-treatment effects.nnnMETHODSnWe studied 83 stable geriatric patients in long-term care (aged 56 to 98 years) who were treated with low-dose aspirin (100 mg/d) for 2 weeks and 40 control patients. Other medications and diet were kept constant. Biochemical monitoring including blood samples and 24-hour urinary collections for creatinine and uric acid at baseline and weekly for a total of 5 weeks.nnnRESULTSnAfter 2 weeks on aspirin, urinary excretion of creatinine decreased in 60 (72%) and excretion of uric acid decreased in 54 (65%) of the 83 patients, and their mean clearances decreased; during the same period, serum blood urea nitrogen, creatinine, and uric acid levels increased (P <0.05 for all). Deterioration from baseline levels was significantly greater (and more prevalent) in the aspirin-treated group than in the 40 control patients (P = 0.001 to 0.09). After withdrawal of aspirin these parameters improved. However, 3 weeks after stopping aspirin, 48% (35 of the 73 in whom this measurement was available) had a persistent decline in creatinine clearance from baseline, as compared with only 8% (3/36) controls (P <0.001).nnnCONCLUSIONnShort-term low-dose aspirin treatment may affect renal function in elderly patients. These effects persist 3 weeks after cessation of the drug in some of these patients.


Arthritis & Rheumatism | 1998

The impact of hemiparalysis on the expression of osteoarthritis

Rafael Segal; Eliezer Avrahami; Ela Lebdinski; Beno Habut; Arthur Leibovitz; Israel Gil; Michael Yaron; Dan Caspi

OBJECTIVEnPrimary generalized osteoarthritis (OA), the most prevalent joint disease, is usually symmetric. Sporadic case reports mention decreased OA manifestations in limbs in which there are neurologic deficits, but no systematic research has been published. The aim of the present study was to examine these observations in a planned and controlled survey in a group of patients with OA.nnnMETHODSnSeventy-five geriatric patients with a history of stroke and hemiparalysis were studied clinically and radiographically (hand radiographs; graded according to a modified Altman method) for the presence and the degree of OA in the hands. Detailed clinical and radiologic scores were calculated for each hand. Demographic, occupational, and neurologic data were collected. Patients with other joint or neurologic conditions were excluded. A group of 55 elderly patients without stroke were similarly studied (controls). Scores in the paralyzed hand were compared with those in the nonparalyzed hand in the stroke patients and subgroups (by Students paired t-test and Wilcoxon test). Scores in the dominant hands were compared with those in the nondominant hands in stroke patients and control subjects (by Students paired t-test and Mann-Whitney test). Correlation between the degree of neurologic damage and OA asymmetry (Pearsons correlation coefficient) was also sought.nnnRESULTSnParalyzed hands showed significantly fewer OA changes than nonparalyzed hands, both clinically and radiologically. This trend, accentuated in patients with more severe paralysis, disappeared in those with mild residual paresis. Asymmetry of OA was more pronounced in patients with flaccid, compared with spastic, paralysis. The degree of paralysis and loss of muscle strength correlated with the degree of OA asymmetry. Women had significantly higher OA scores than men. In the control group, dominant hands had higher OA scores, but this finding was concealed among hemiparalyzed patients. Lifetime gross occupational load and present grip strength did not correlate with the degree of OA.nnnCONCLUSIONnIn elderly patients, hemiparalysis reduces ipsilateral hand expression of OA, while OA is accentuated (or increased) in the dominant hand of patients without paralysis. This first systematic study confirms the findings of previous case reports and lends support to the role of biomechanical factors in the development of OA.


Clinical Rheumatology | 2000

Serum Levels of Hyaluronic Acid in Patients with Psoriatic Arthritis

Ori Elkayam; I. Yaron; Idit Shirazi; Michael Yaron; Dan Caspi

Abstract: The purpose of this study was to evaluate the serum levels of hyaluronic acid (HA) in a group of patients with psoriatic arthritis (PsA), with special emphasis on the relationships between HA levels and clinical parameters of joint and skin activity. Thirty-four patients with PsA, 34 patients with rheumatoid arthritis (RA) and 49 healthy volunteers participated in the study. Assessment of joint disease in patients with PsA included duration of morning stiffness, number of tender and swollen joints, right and left grip, the presence of inflammatory back pain and Schober’s test. The current severity of skin involvement was graded according to the Psoriasis Area Severity Index (PASI). Serum levels of HA were measured by a radiometric assay. The mean HA serum levels of patients with PsA and RA were significantly increased in comparison with healthy controls (107 ± 39.6 μg/dl in patients with PsA, whereas in patients with RA it was 168 ± 32.4 μg/dl and 36.7 ± 5.5 μg/dl in healthy controls). A highly significant correlation was found between levels of HA and index of skin involvement, but no association was found between HA levels and clinical parameters of joint severity. We conclude that in this cohort of patients with PsA, HA levels clearly reflected psoriatic skin involvement although it did not correlate with joint disease.


Rheumatology International | 2001

Clinical significance of low titer anti-nuclear antibodies in early rheumatoid arthritis: implications on the presentation and long-term course of the disease

Dan Caspi; Ori Elkayam; Miruna Eisinger; Nurit Vardinon; Michael Yaron; Michael Burke

Abstract The objective of this study was to evaluate the clinical significance of anti-nuclear antibodies (ANA) detected in the early stages of rheumatoid arthritis (RA), by a retrospective comparison of the clinical, laboratory, and therapeutic characteristics of patients with or without ANA. The files of 99 longstanding seropositive RA patients were reviewed. Data relating to demographics, medical history, family history, physical findings, extra-articular complications, laboratory tests, drugs [dosage, duration, efficacy, combinations, adverse effects (AEs)], intra-articular injections, and surgery were recorded. Patients with or without ANA at presentation of their disease were compared using chi-square and t-tests. Fifty-two ANA positive (group 1) and 47 ANA negative (group 2) patients were enrolled in the study. All were comparable in terms of their mean age, age at diagnosis, follow-up duration (∼10.5u2009years), and male:female (M:F) ratio. On admission, pain complaints were more pronounced in group 1 (P = 0.004 in the feet), but the physical findings did not differ. Deformities and nodules developed in similar numbers. Extra-articular complications were evenly distributed; vasculitis, however, was significantly more prevalent in ANA positive (10/52) than in ANA negative (2/47) patients. Thyroid disease was more common in group 2 (10/47 vs 3/52). Laboratory tests (presentation and maximal values) were similar, with the exception of higher anti-DNA (but within normal ranges) and γ-globulin% in group 1. Group 1 used more drugs prior to diagnosis. Corticosteroids and disease-modifying anti-rheumatic drugs (DMARDs) were evenly used. Combination therapy, joint injections, and surgery were more prevalent in group 2. AEs to various DMARDs were more common in group 1. Although similar in many aspects, RA patients with ANA tend to present with more pain complaints, a higher risk of vasculitis and AEs relating to use of DMARDs, while those without ANA needed more aggressive therapeutic modalities.


Rheumatology International | 1996

The lack of prognostic value of computerized tomography imaging examinations in patients with chronic non-progressive back pain

O. Elkayam; E. Avrahami; Michael Yaron

The purpose of the present study was to evaluate the prognostic value of computerized tomography (CT) in the conservative treatment of patients with chronic non-progressive back pain. The study included 73 patients with chronic non-progressive back pain in the lumbar region of at least 3-months duration who were referred to the back clinic because of pain that was non-responsive to physical therapy and analgesics. All patients underwent clinical examination and spinal CT scan. The clinical examination and imaging procedures were followed by a 4-week rehabilitation programme based on a multidisciplinary approach that included a rheumatologist, a pain specialist, back school, “Alexander” technique, acupuncture, manipulation and psychological intervention. Patients were evaluated by the same physician at the end of the 4-week programme and after 6 months follow-up using parameters of pain rating, pain frequency and analgesic drug consumption. CT examinations were evaluated separately by two radiologists. The patients were divided into three groups according to the CT findings: group 1 — normal imaging: 26 patients; group 2 — spinal stenosis: 20 patients; group 3 — posterior bulging, protrusion, extrusion or sequestration of disc: 27 patients. The clinical improvement was almost the same (=50%) in the three different groups. In spite of the small number of cases, the results were statistically significant. We concluded that, in contrast to the importance of modern spinal-imaging procedures before the performance of surgery, the role of these procedures in the prognosis of the conservative treatment of patients with chronic non-progressive back pain does not seem to be important.

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Dan Caspi

Tel Aviv Sourasky Medical Center

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Daphna Paran

Tel Aviv Sourasky Medical Center

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I. Yaron

Tel Aviv Sourasky Medical Center

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Idit Shirazi

Tel Aviv Sourasky Medical Center

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Irena Wigler

Tel Aviv Sourasky Medical Center

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Ayala Lagziel

Tel Aviv Sourasky Medical Center

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