Simultaneous assessment of cardiac perfusion and function using 5-dimensional imaging with Tc-99m teboroxime

BACKGROUND: Dynamic single photon emission computed tomography (SPECT) acquisition and reconstruction of early poststress technetium 99m teboroxime washout images has been shown to be useful in the detection of coronary disease. Assessment of poststress regional wall motion may offer additional use in assessing coronary disease. Our goal was to investigate the feasibility of simultaneously imaging myocardial ischemia and transient poststress akinesis using gated-dynamic SPECT. METHODS AND RESULTS: A gated-dynamic mathematical cardiac torso (MCAT) phantom was developed to model both teboroxime kinetics and cardiac regional wall motion. A lesion was simulated as having delayed poststress teboroxime washout together with a transient poststress wall motion abnormality. Gated projection data were created to represent a 3-headed SPECT system undergoing a total rotation of 480 degrees . The dynamic expectation-maximization reconstruction algorithm with postsmoothing across gating intervals by Wiener filtering, and the ordered-subset expectation maximization reconstruction algorithm with 3-point smoothing across gating intervals were compared. Compared with the ordered-subset expectation maximization with 3-point smoothing, the dynamic expectation-maximization algorithm with Wiener filtering was able to produce visually higher-quality images and more accurate left ventricular ejection fraction estimates. CONCLUSION: From simulations, we conclude that changing cardiac function and tracer localization possibly can be assessed by using a gated-dynamic acquisition protocol combined with a 5-dimensional reconstruction strategy.     

Avoiding laboratory test misinterpretation in geriatric rheumatology

In this review, basic principles of test selection and interpretation are applied to those serologic studies of most value to the clinician attempting to diagnose rheumatic disease in the elderly--erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and fluorescent anti-nuclear antibody (FANA). Essentials of each test are discussed and the significance of "normal" and "abnormal" results is illustrated in varied clinical circumstances. None of the tests is diagnostic and because false positive results are more common in healthy elderly subjects, the clinician faces the pitfall of overdiagnosis. Clinical findings remain the cornerstones for the diagnosis of rheumatic disease, and selected tests are used to refine the pretest assessments of disease probability.     

Stress,coping, family conflict,and adolescent alcohol use

This study examined alcohol use among seventh graders in relation to life events, daily hassles, the supportive quality of the family environment, coping, and anxiety. Four hundred twenty-five students participated, 228 girls and 197 boys. Stepwise regression and discriminant function analyses indicated that the students reported more alcohol use if they also reported more life events, more daily hassles, and more conflict in the family. A stress-buffering effect of low family conflict on life events could not be substantiated for extent of alcohol use. The results are discussed in the context of the developmental transitions of adolescence.     

Damaged chromatin does not prevent the exit from metaphase I in fused mouse oocytes

The presence of checkpoint mechanisms which are able to recognize damaged chromatin and thereafter to prevent exit from metaphase I has been investigated in giant mouse oocytes produced by fusion of a normal metaphase I oocyte with an equivalent oocyte with damaged chromatin. The presence of damaged chromatin did not prevent the onset of anaphase I in both sets of chromatin in the fused cells. Interestingly, fused or unfused cells containing only damaged chromatin failed to enter anaphase and persisted instead in a metaphase-like state. These results demonstrate the fragility of checkpoint controls in mammalian female germ cells.      

An extended diffraction-enhanced imaging method for implementing multiple-image radiography

Diffraction-enhanced imaging (DEI) is an analyser-based x-ray imaging method that produces separate images depicting the projected x-ray absorption and refractive properties of an object. Because the imaging model of DEI does not account for ultra-small-angle x-ray scattering (USAXS), the images produced in DEI can contain artefacts and inaccuracies in medical imaging applications. In this work, we investigate an extended DEI method for concurrent reconstruction of three images that depict an object's projected x-ray absorption, refraction and USAXS properties. The extended DEI method can be viewed as an implementation of the recently proposed multiple-image radiography paradigm. Validation studies are conducted by use of computer-simulated and synchrotron measurement data.     

A double mobility acetabular implant for primary hip arthroplasty in patients at high risk of dislocation

IntroductionDislocation following total hip replacement continues to be a problem for which no completely satisfactory solution has been found. Several methods have been proposed to reduce the incidence of hip dislocations with varying degrees of success, including elevated rim liners, constrained liners and large diameter bearings. We present our experience with the double mobility acetabular component in patients at high risk of instability.MethodsThis was a retrospective review of 65 primary total hip arthroplasties in 55 patients (15 men, 40 women), performed between October 2005 and November 2009. The majority (80%) of patients had at least two and 26% had at least three risk factors for instability. The mean age was 76 years (range: 44–92 years). The patients were followed up for a mean duration of 60 months (range: 36–85 months).ResultsFourteen patients died and one was lost to follow-up, leaving fifty hips for final assessment. Until the final follow-up appointment, no patients had dislocation and none required revision surgery. The mean Oxford hip score improved from 45.0 to 26.5 (p<0.0001). The mean Merle d’Aubigné pain score improved from 1.4 to 4.9 (p<0.0001), the walking score from 2.3 to 3.1 (p<0.07) and the absolute hip function score from 5.4 to 10.8 (p<0.0001). There were no clinical or radiographic signs of loosening.ConclusionsThe double mobility acetabular component was successful at preventing dislocation during early to medium-term follow-up. However, as data are still lacking with regard to polyethylene wear rates at the additional bearing surface, it would be prudent to restrict the use of this implant to selected patients at high risk of instability.     

Plasma chemistry reference values in the gyr falcon (Falco rusticolus)

Blood samples were collected from 102 clinically healthy gyr falcons (Falco rusticolus) over a time period of approximately 3 years as part of routine examination procedures. Standard blood chemistry analyses were carried out to establish normal reference values for the species. Plasma chemistry analyses included alkaline phosphatase (ALP), amylase, blood urea nitrogen, bile acids, calcium, cholesterol, creatinine, creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), glucose, phosphate, iron, total protein, total bilirubin, and uric acid. Reference intervals were determined using a quantile approach with 90 % confidence intervals of the limits. Juveniles and adults differ in ALT, creatinine, AST, glucose, LDH, and uric acid. Sexes differ in ALP, CK, AST, and phosphorus. This study provides valuable information on the plasma biochemistry values for gyr falcons that may help in the medical management of this endangered and commonly used falconry species.     

Serum IgG and IgM Rheumatoid Factors by Solid Phase Radioimmunoassay

In this report, solid phase radioimmunoassays that specifically measure IgG rheumatoid factor (RF) and IgM RF in absolute concentrations are described. Polyclonal RF preparations were utilized as standards, and as little as 40 ng/ml of IgG RF and 1 ng/ml of IgM RF were detected. The IgG RF concentration of 26 seropositive rheumatoid sera was 439 ± 755 μg/ml (mean ± 1 SD), a level 107 times that of normal controls (P < 0.001). In contrast, levels for 49 children with juvenile rheumatoid arthritis (JRA) were 6.1 ± 3.7 μg/ ml for those with a polyarticular onset (JRA-Po), 27.3 ± 113 μg/ml for the pauciarticular group (JRA-Pa), and 12.6 ± 20.7 μg/ml for the group with a systemic onset (JRA-S). None of these values differed significantly from the value of 6.0 ± 3.9 μg/ml measured in a juvenile control group. The IgM RF level in adult rheumatoid arthritis (RA) of 175 ± 221 μg/ml was also significantly elevated compared to controls (P < 0.001). In JRA, however, mean levels of 1.4 ± 2.0 μg/ml (JRA-Po), 2.8 ± 8.3 μg/ml (JRA-Pa), and 1.1 ± 0.7 μg/ml (JRA-S) were not elevated significantly above the value of 1.2 μ 1.2 μg/ml measured in the juvenile control group. Hidden IgM RF was not found in 9 JRA sera tested. These marked differences in RF levels provide another indication that adult RA and JRA are distinct diseases.