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Biomedical subjects

S Zaim

Publications and source records attributed to S Zaim.

At least 19 recordsLinked to original sources
PubMed2006

Longitudinal study of magnetic resonance imaging and standard X-rays to assess disease progression in osteoarthritis.

OBJECTIVE: To investigate, over 1-year, the relationship between X-ray and magnetic resonance imaging (MRI) findings in patients with knee osteoarthritis (OA). METHODS: Sixty-two osteoarthritic patients (46 women) were followed for 1 year. At baseline and after 1 year, volume and thickness of cartilage of the medial tibia, the lateral tibia and the femur were assessed by MRI. A global score from the multi-feature whole-organ MRI scoring system (WORMS) was calculated for each patient at baseline and after 1 year. This score combined individual scores for articular cartilage, osteophytes, bone marrow abnormality, subchondral cysts and bone attrition in 14 locations. It also incorporated scores for the medial and lateral menisci, anterior and posterior cruciate ligaments, medial and lateral collateral ligaments and synovial distension. Lateral and medial femoro-tibial joint space width (JSW) measurements, performed by digital image analysis, were assessed from fixed-flexion, postero-anterior knee radiographs. RESULTS: One-year changes in medial femoro-tibial JSW reach 6.7 (20.5) % and changes in medial cartilage volume and thickness reach 0.4 (16.7) % and 2.1 (11.3) %, respectively. Medial femoro-tibial joint space narrowing (JSN) after 1 year, assessed by radiography, was significantly correlated with a loss of medial tibial cartilage volume (r=0.25, P=0.046) and medial tibial cartilage thickness (r=0.28, P=0.025), over the same period. We found also a significant correlation between the progression of the WORMS and radiographic medial JSN over 1 year (r=-0.35, P=0.006). All these results remained statistically significant after adjusting for age, sex and body mass index. CONCLUSION: This study shows a moderate but significant association between changes in JSW and changes in cartilage volume or thickness in knee joint of osteoarthritic patients.

Aged↗
PubMed2006

Osteoarthritis, magnetic resonance imaging, and biochemical markers: a one year prospective study.

OBJECTIVE: To investigate the relation between biochemical markers of bone, cartilage, and synovial remodelling and the structural progression of knee osteoarthritis. METHODS: 62 patients of both sexes with knee osteoarthritis were followed prospectively for one year. From magnetic resonance imaging (MRI), done at baseline and after one year, the volume and thickness of cartilage of the femur, the medial tibia, and the lateral tibia were assessed. A whole organ magnetic resonance imaging score (WORMS) of the knee was calculated for each patient at baseline and at the one year visits. This score consists in a validated, semiquantitative scoring system for whole organ assessment of the knee in osteoarthritis using MRI. Biochemical markers (serum hyaluronic acid, osteocalcin, cartilage glycoprotein 39 (YKL-40), cartilage oligomeric matrix protein (COMP), and C-telopeptide of type I collagen (CTX-I), and urine C-telopeptide of type II collagen (CTX-II)) were measured at baseline and after three months. RESULTS: Baseline markers were not correlated with one year changes observed in cartilage volume and thickness. However, an increase in CTX-II after three months was significantly correlated with a one year decrease in mean thickness of medial tibial and lateral tibial cartilage. Patients in the highest quartile of three month changes in CTX-II experienced a mean loss of 0.07 (0.08) mm of their medial thickness, compared with a mean increase of 0.05 (0.19) mm for patients in the lowest quartile (p = 0.04) Multiple regression analysis showed that high baseline levels of hyaluronic acid are predictive of a worsening in WORMS (p = 0.004). CONCLUSIONS: These results suggest that a single measurement of serum hyaluronic acid or short term changes in urine CTX-II could identify patients at greatest risk of progression of osteoarthritis.

Adipokines↗
PubMed2005

Bone marrow abnormalities on magnetic resonance imaging are associated with type II collagen degradation in knee osteoarthritis: a three-month longitudinal study.

OBJECTIVE: Using radiography to assess the efficacy of a disease-modifying osteoarthritis (OA) drug on joint structure is challenging. Subchondral bone marrow abnormalities determined by magnetic resonance imaging (MRI) and urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) have recently been shown to be predictors of radiographic progression in patients with knee OA, suggesting that these may represent valuable biomarkers with increased sensitivity compared with findings on radiography. The aims of this investigation were to analyze, in patients with knee OA, whether the values associated with these 2 OA biomarkers can change within 3 months, and to investigate the relationships between bone marrow abnormalities and CTX-II. METHODS: Knee MRI scans were obtained in 377 patients with painful knee OA (76% women, mean age 63 years, mean disease duration 6.6 years) at both baseline and 3 months. The femoral and tibial condyles and the patella were divided into 8 sites for the scoring of bone marrow abnormalities. A bone marrow abnormality was defined as an area of increased signal on T2-weighted images of the subchondral bone. All scans were reviewed centrally and scored by a single trained radiologist using a validated 4-point scoring method. Fasting urine and serum samples were also collected from all patients at baseline, month 1, month 2, and month 3, in order to measure the levels of urinary CTX-II and serum CTX-I, a biochemical marker of bone resorption. RESULTS: At baseline, 82% of patients had MRI evidence of bone marrow abnormalities. Bone marrow abnormality scores correlated significantly with CTX-II levels (P < 0.0001). Within 3 months, the bone marrow abnormality score decreased in 37 patients (9.8%), increased in 71 patients (18.8%), and did not change in the majority of patients (71.4%). Patients with baseline urinary CTX-II levels in the highest tertile had a relative risk of 2.4 (95% confidence interval 1.1-5.0) of worsening bone marrow abnormalities at 3 months compared with patients with levels in the lowest tertile, after adjustment for age, sex, and body mass index. In patients who showed a decrease in the bone marrow abnormality score at 3 months, urinary CTX-II levels decreased significantly (mean -75 ng/mmole creatinine), whereas levels increased (mean +23 ng/mmole creatinine) in patients showing an increase in the bone marrow abnormality score (P = 0.01 between the 2 groups). No significant association between bone marrow abnormalities and serum CTX-I was observed. CONCLUSION: In patients with painful knee OA, bone marrow abnormalities on MRI can change within only 3 months in approximately 30% of patients. Reduction in the extent of bone marrow abnormalities is associated with a decrease in cartilage degradation.

Biomarkers↗
PubMed2005

Orthostatic intolerance and syncope associated with Chiari type I malformation.

The Chiari type I malformation (CM1) is characterized by herniation of cerebellar tonsils to at least 3-5 mm below the plane of foramen magnum and can present with a wide variety of clinical symptoms, frequently including occipital headaches, secondary to bulbar and/or medullary distress. Rarely, syncopal episodes have also been described and attributed to either compression of the midbrain ascending reticular system, or vascular compromise (vertebrobasilar artery compression, hypotension). We report the first case of a CM1 patient with frequently recurring syncope due to postural orthostatic tachycardia syndrome (POTS), a form of orthostatic intolerance, whose symptoms resolved completely after surgical intervention. It is important to stress that it is not clear whether the described association of POTS and CM1 in our patient is a fortuitous finding in an isolated case or a reflection of a more systematic association between the two pathologies.

Adult↗
PubMed2004

Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the knee in osteoarthritis.

OBJECTIVES: To describe a semi-quantitative scoring method for multi-feature, whole-organ evaluation of the knee in osteoarthritis (OA) based on magnetic resonance imaging (MRI) findings. To determine the inter-observer agreement of this scoring method. To examine associations among the features included in the scoring method. METHODS: Nineteen knees of 19 patients with knee OA were imaged with MRI using conventional pulse sequences and a clinical 1.5 T MRI system. Images were independently analyzed by two musculoskeletal radiologists using a whole-organ MRI scoring method (WORMS) that incorporated 14 features: articular cartilage integrity, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes, medial and lateral meniscal integrity, anterior and posterior cruciate ligament integrity, medial and lateral collateral ligament integrity, synovitis/effusion, intraarticular loose bodies, and periarticular cysts/bursitis. Intraclass correlation coefficients (ICC) were determined for each feature as a measure of inter-observer agreement. Associations among the scores for different features were expressed as Spearman Rho. RESULTS: All knees showed structural abnormalities with MRI. Cartilage loss and osteophytes were the most prevalent features (98% and 92%, respectively). One of the least common features was ligament abnormality (8%). Inter-observer agreement for WORMS scores was high (most ICC values were >0.80). The individual features showed strong inter-associations. CONCLUSION: The WORMS method described in this report provides multi-feature, whole-organ assessment of the knee in OA using conventional MR images, and shows high inter-observer agreement among trained readers. This method may be useful in epidemiological studies and clinical trials of OA.

Aged↗
PubMed2003

Comparison of fixed-flexion positioning with fluoroscopic semi-flexed positioning for quantifying radiographic joint-space width in the knee: test-retest reproducibility.

OBJECTIVE: To compare fixed-flexion radiography of the knee with fluoroscopic semi-flexed radiography in terms of the reproducibility of measurements of minimum joint-space width (JSW) in the medial femorotibial joint. METHODS: Posteroanterior radiographs of the right knees of 18 normal volunteers were acquired with the patients standing on an upright fluoroscopy table, the feet externally rotated 10 degrees and the toes touching the vertical table. Knees were positioned and radiographed with two different techniques: (1) semi-flexed positioning under fluoroscopic guidance using a horizontal X-ray beam; and (2) fixed-flexion positioning, with the knees and thighs touching the vertical table, using 10 degrees caudal beam angulation without fluoroscopy. Foot maps were drawn in each case. Subjects were repositioned and radiographed twice using each technique. The posteroanterior beam angle that optimally projected the medial tibia plateau with the patient in the fixed-flexion position was also determined for each subject in a separate examination using fluoroscopy. Ten patients with osteoarthritis were also examined with the fixed-flexion technique using a conventional radiographic unit. Minimum medial joint-space width (JSW) in the medial femorotibial joint was measured manually with a graduated lens and also with a semi-automated computer algorithm. RESULTS: Reproducibility errors (root-mean-square SD) for manual and automated JSW measurement were 0.2 mm and 0.1 mm, respectively, for fluoroscopic semi-flexed positioning in volunteers; 0.3 mm and 0.1 mm, respectively, for fixed-flexion positioning in volunteers; and 0.2 mm and 0.1 mm, respectively, for fixed-flexion positioning in osteoarthritic patients. The optimal beam angle for visualizing the joint space was 9.0 degrees +/-3.6 degrees. CONCLUSION: Fixed-flexion, non-fluoroscopic radiography of the knee can provide reproducible JSW measurement using widely available X-ray equipment. This technique is more feasible for multicenter clinical studies and routine clinical use than are methods that rely on fluoroscopic alignment of the tibial plateau.

Adult↗
PubMed2003

Metallic artefacts in MR imaging: effects of main field orientation and strength.

AIM: To determine the effect of metallic implant positioning on magnetic resonance (MR) imaging artefacts, and to determine the optimal imaging parameters for minimization of metallic artefacts. MATERIALS AND METHODS: In a phantom and in three joints with non-ferromagnetic metallic implants imaged at 1.5 and/or at 0.2 T, we examined the influence of the static magnetic field (B(0)) strength and orientation, frequency-encoding direction, and type of imaging sequence on metallic artefacts. RESULTS: The impact of artefacts caused by metallic objects depends mainly on the relationship between the anatomy of interest and the orientation of the object relative to the direction of B(0). The main field strength plays a less important role, but its orientation depends on the type of MR imager. CONCLUSION: MR artefacts can be easily minimized by optimally positioning patients with metallic implants in the magnet. Knowledge of how this influences MR imaging is helpful in patient selection and guiding limb positioning.

Artifacts↗
PubMed2003

Ictal bradycardia in a young child with focal cortical dysplasia in the right insular cortex.

We report on a three and a half year old child with episodic sinus bradycardia during habitual seizures and prolonged interictal discharges due to focal cortical dysplasia in the anterior 2/3 of the insula and the inferior frontal cortex. Seizure-induced bradycardia is rarely reported in children. Bradycardia is suspected to be related to sudden death, a rare complication of a chronic seizure disorder. Several well-documented cases in adult patients reveal a high incidence of temporal epilepsy, but MRI and PET studies in healthy subjects suggest a major role of the insular cortex, especially the right, in cardiac regulation. Our finding underlines the predominance of the right insula in cardiac control, which already seems to be present in children.

Bradycardia↗
PubMed2003

New radiographic-based surrogate outcome measures for osteoarthritis of the knee.

OBJECTIVE: Minimum joint space width (mJSW) between the femoral condyle and tibial plateau is currently the principal radiographic outcome measure for knee osteoarthritis (OA). While mJSW measurement has been proven effective, there is a need for quantitative measures with greater sensitivity to OA so studies of disease modifying trials can be performed more quickly and with fewer subjects. Also, mJSW is a single outcome measure that does not reflect all disease changes. Here we present a study of new radiograph-based outcome measures to quantify OA progression. DESIGN: Our goal is made possible by a software algorithm that delineates both the edge of the tibial plateau and the femoral condyle on digitized knee radiographs. We also developed a new coordinate system based on anatomical landmarks to facilitate measurement of the outcome measures. We studied measurements of joint space width (JSW) and average JSW at fixed locations along the joint interface. The outcome measures were tested using duplicate acquisitions made from 16 OA and 18 normal knees. Reproducibility was quantified by the root-mean square standard deviation and the coefficient of variation. RESULTS: We found that the reproducibility for all outcome measures was better than or similar to that for mJSW. Despite a slightly higher reproducibility error for some new outcome measures compared to mJSW, they are potentially valuable since they reflect independent disease changes. CONCLUSION: We have demonstrated new reproducible radiographic outcome measures to quantify OA progression with the potential to be an improvement over standard minimum joint space width.

Adult↗
PubMed2002

Temporal lobe epilepsy and postural orthostatic tachycardia syndrome (POTS).

We describe a 20-year-old woman suffering from right temporal epilepsy, behavioral disorder, and a complaint of paroxysmal palpitations accompanied by anxiety. Detailed cardiac evaluation revealed that the palpitations were due to episodes of marked sinus tachycardia secondary to a concomitant postural orthostatic tachycardia syndrome (POTS) and not of psychogenic origin as initially thought. Treatment with a beta-blocker resulted in the disappearance of palpitations and the associated anxiety. This is the first report of the coexistence of partial epilepsy and POTS. The recognition of such a syndrome in epileptic patients is important in order to offer appropriate therapy.

Journal Article↗
PubMed2002

Inappropriate high-rate ventricular pacing in a patient with a defibrillator.

We describe a patient who presented with high rate ventricular pacing secondary to dysfunction of his implantable cardioverter defibrillator (ICD). The device was also unable to communicate with the programmer and unable to treat ventricular fibrillation. Immediate disconnection of the ICD from the leads was the only effective recourse. Subsequent detailed technical analysis of the device revealed a different electrical circuit problem from that found in typical cases of runaway pacing. To our knowledge this is the first description of a malfunction of precisely this nature.

Aged↗
PubMed2002

Neural network based automated algorithm to identify joint locations on hand/wrist radiographs for arthritis assessment.

Arthritis is a significant and costly healthcare problem that requires objective and quantifiable methods to evaluate its progression. Here we describe software that can automatically determine the locations of seven joints in the proximal hand and wrist that demonstrate arthritic changes. These are the five carpometacarpal (CMC1, CMC2, CMC3, CMC4, CMC5), radiocarpal (RC), and the scaphocapitate (SC) joints. The algorithm was based on an artificial neural network (ANN) that was trained using independent sets of digitized hand radiographs and manually identified joint locations. The algorithm used landmarks determined automatically by software developed in our previous work as starting points. Other than requiring user input of the location of nonanatomical structures and the orientation of the hand on the film, the procedure was fully automated. The software was tested on two datasets: 50 digitized hand radiographs from patients participating in a large clinical study, and 60 from subjects participating in arthritis research studies and who had mild to moderate rheumatoid arthritis (RA). It was evaluated by a comparison to joint locations determined by a trained radiologist using manual tracing. The success rate for determining the CMC, RC, and SC joints was 87%-99%, for normal hands and 81%-99% for RA hands. This is a first step in performing an automated computer-aided assessment of wrist joints for arthritis progression. The software provides landmarks that will be used by subsequent image processing routines to analyze each joint individually for structural changes such as erosions and joint space narrowing.

Algorithms↗
PubMed2001

Symptomatic postictal cardiac asystole in a young patient with partial seizures.

This report describes a patient with complex partial seizures arising from the right temporal lobe who developed symptomatic sinus arrest following the end of his seizure activity. A ventricular pacemaker was implanted and was documented to function appropriately, preventing development of bradycardia associated symptoms during subsequent seizures. Possibly relevant cerebral structures are briefly discussed.

Adult↗
PubMed1999

Rhabdomyolysis associated with naltrexone.

OBJECTIVE: To report a possible association between naltrexone therapy and the development of rhabdomyolysis in one patient. CASE SUMMARY: A 28-year-old white man in good physical health was started on naltrexone 50 mg/d for inpatient treatment of alcohol dependence and depression. A routine serum chemistry panel obtained on day 9 of naltrexone therapy showed marked new elevations in creatine kinase and aspartate aminotransferase. The patient remained asymptomatic and did not develop renal insufficiency. The serum enzyme concentrations returned to normal within eight days of naltrexone discontinuation. DISCUSSION: Rhabdomyolysis has not been previously reported to occur in patients during treatment with naltrexone. Alcoholism may result in a reversible acute muscle syndrome, but our patient did not fit the appropriate clinical profile for such a syndrome. Additionally, the other prescribed medications could not be implicated as possible causative agents. CONCLUSIONS: This case report illustrates a possible association between naltrexone therapy and rhabdomyolysis.

Adult↗
PubMed1998

Perirenal textiloma: MR and serial CT appearance.

We describe changes in imaging features of a textiloma (retained surgical sponge or retained foreign body) left in the renal fossa after exploratory renal surgery. One year after the initial surgery, the MR aspect of the textiloma was not specific, with a homogeneous low signal intensity on T1-weighted images. Serial CT examinations over 4 years demonstrated progressive growth and calcification of the mass which appeared pseudocystic with a peripheral inflammatory wall. Granulomas caused by a retained surgical sponge should be considered as a cause of retroperitoneal mass in patients with a history of prior surgery.

Adult↗
PubMed1998

Lymph node metastases: safety and effectiveness of MR imaging with ultrasmall superparamagnetic iron oxide particles--initial clinical experience.

PURPOSE: To evaluate the clinical and biologic safety of ultrasmall superparamagnetic iron oxide particles (AMI-227) as a contrast agent for magnetic resonance (MR) lymphography and to assess their efficacy for the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancer. MATERIALS AND METHODS: Thirty adults suspected of having lymph node metastases underwent MR imaging before and 22-26 hours after intravenous infusion of AMI-227 (1.7 mg Fe/kg). Sixty histopathologically proved lymph nodes were analyzed on MR images, and 29 of these nodes were also analyzed quantitatively. RESULTS: AMI-227 was well tolerated with no major side effects. It allowed the detection of 10 additional nodes relative to those detected at MR imaging without AMI-227. None of the 27 metastatic nodes showed a decrease in signal intensity (SI) on AMI-227-enhanced images; nine of 27 metastatic nodes showed an increase in SI on T1-weighted images, probably resulting from altered capillary permeability in the tumor. A visually perceptible reduction in SI, indicating active AMI-227 uptake, was observed on postcontrast T2- and T2*-weighted images in 16 of 21 benign nodes. The SI ratio of benign nodes was lower than that of metastatic nodes on T2- and T2*-weighted images. The sensitivity of AMI-227-enhanced MR lymphography was 100%, and the specificity was 80%. CONCLUSION: AMI-227 is safe and may facilitate the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancers.

Adult↗
PubMed1996

Effects of pinacidil, verapamil, and heart rate on afterdepolarizations in the guinea-pig heart in vivo.

Recently, ionic current simulation in the Luo-Rudy model has elucidated putative mechanisms of afterdepolarizations under various experimental conditions. The present study was aimed at gaining insight into the differential mechanism of different types of afterdepolarizations in the guinea-pig heart in vivo. The effects of pharmacological and heart rate perturbations on early (EADs) and delayed (DADs) afterdepolarizations, induced by either digoxin, CsCl, or BayK 8644 were studied, using mid-myocardial left ventricular monophasic action potential (MAP) recordings. Digoxin insignificantly shortened sinus cycle length (SCL) and CsCl and BayK 8644 differentially prolonged SCL and MAP duration. Digoxin induced phase 3-EADs and DADs and CsCl or BayK 8644 induced phase 2- and phase 3-EADs. Pinacidil shortened MAP duration, suppressed almost all the phase 2-EADs and some of the phase 3-EADs, but not the DADs. In a few cases, DADs were manifested following the abolishment of phase 2-EADs by pinacidil, but this phenomenon did not occur in the presence of hexamethonium. Verapamil prolonged SCL, did not significantly affect phase 2-EADs, but suppressed almost all of the DADs, including those which appeared after pinacidil, and all but one of the phase 3-EADs. The effects of pinacidil and verapamil were independent of the mode of afterdepolarization induction. A pacing-induced heart rate increase, which shortened MAP duration, and vagal stimulation, which prolonged MAP duration, attenuated and enhanced phase 2-EADs, respectively. The amplitude of phase 3-EADs was inversely related to the heart rate. These data, taken together, are consistent with those obtained previously by others in a computer model and recent observations on CsCl-induced EADs in the guinea-pig Purkinje fibers in vitro which have indicated that the mechanism of phase 2-EADs is different from that of DADs and that late phase 3-EADs generated under conditions of Ca2+ overload and DADs share similar properties.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗