Citations

Background— Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion. Methods and Results— Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annular dimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software. Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1±0.1 mm; P =0.73; 95% confidence interval, ±4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P <0.05). Normal annulus displayed early-systolic anteroposterior ( P <0.001) and area ( P =0.04) contraction, increased height ( P <0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15±1% to 21±1%; P <0.001), whereas intercommissural diameter was unchanged ( P =0.30). In contrast, MVD showed early-systolic intercommissural dilatation ( P =0.02) and no area contraction ( P =0.99), height increase ( P =0.11), or saddle-shape deepening ( P =0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged ( P <0.04) as a result of persistent intercommissural widening ( P <0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation ( P =0.30). Conclusions— Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annular decoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

BACKGROUND: Open irrigation and débridement is the standard of treatment for septic arthritis of the wrist. Although isolated cases of arthroscopic irrigation and débridement have been reported, a comparison of arthroscopic and open techniques has not been performed, to our knowledge. The purpose of this study was to compare the two methods of management. METHODS: A retrospective comparison of patients with septic arthritis of the wrist initially treated, over an eleven-year period, with open or arthroscopic irrigation and débridement was undertaken at a single institution. The clinical presentation, laboratory and microbiological findings, hospital course, complications, and outcomes were compared between the two groups. RESULTS: Between 1997 and 2007, thirty-six patients with septic arthritis involving a total of forty wrists were identified. Nineteen wrists (seventeen patients) were initially treated with open irrigation and débridement, and twenty-one wrists (nineteen patients) were initially treated arthroscopically. Eleven wrists in the open-treatment cohort required repeat irrigation and débridement, and eight wrists in the arthroscopy cohort required a repeat procedure. If a repeat irrigation and débridement was required, it was performed in an open fashion in all but two cases. When the comparison included all of the patients in the series, no difference between the two cohorts was found with regard to the number of irrigation and débridement procedures required or the length of the hospital stay. However, when the comparison was limited to the patients with isolated septic arthritis of the wrist, it was found that only one of seven wrists in the open-treatment cohort but all eight wrists in the arthroscopy cohort had been successfully managed with a single irrigation and débridement procedure (p = 0.001). No patient in whom isolated septic arthritis of the wrist had been treated with arthroscopic irrigation and débridement required a second operation. The patients in whom isolated septic arthritis of the wrist was treated with the open method stayed in the hospital for an average of sixteen days compared with a six-day stay for those in whom isolated septic arthritis of the wrist was treated with the arthroscopic method (p = 0.04). The ninety-day perioperative mortality rate in the series was substantial (18% [three patients] in the open-treatment cohort and 21% [four patients] in the arthroscopy cohort). CONCLUSIONS: Arthroscopic irrigation and débridement is an effective treatment for patients with isolated septic arthritis of the wrist; these patients had fewer operations and a shorter hospital stay than did patients who had received open treatment. However, these benefits were not seen in patients with multiple sites of infection. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions to Authors for a complete description of levels of evidence. ORIGINAL ABSTRACT CITATION: “Comparison of Arthroscopic and Open Treatment of Septic Arthritis of the Wrist” (2009;91:1387-93).

ABSTRACT Staphylococcus lugdunensis is a coagulase-negative staphylococcus that has several similarities to Staphylococcus aureus . S. lugdunensis is increasingly being recognized as a cause of prosthetic joint infection (PJI). The goal of the present retrospective cohort study was to determine the laboratory and clinical characteristics of S. lugdunensis PJIs seen at the Mayo Clinic in Rochester, MN, between 1 January 1998 and 31 December 2007. Kaplan-Meier survival methods and Wilcoxon sum-rank analysis were used to determine the cumulative incidence of treatment success and assess subset comparisons. There were 28 episodes of S . lugdunensis PJIs in 22 patients; half of those patients were females. Twenty-five episodes (89%) involved the prosthetic knee, while 3 (11%) involved the hip. Nine patients (32%) had an underlying urogenital abnormality. Among the 28 isolates in this study tested by agar dilution, 24 of 28 (86%) were oxacillin susceptible. Twenty of the 21 tested isolates (95%) lacked mecA , and 6 (27%) of the 22 isolates tested produced β-lactamase. The median durations of parenteral β-lactam therapy and vancomycin therapy were 38 days (range, 23 to 42 days) and 39 days (range, 12 to 60 days), respectively. The cumulative incidences of freedom from treatment failure (standard deviations) at 2 years were 92% (±7%) and 76% (±12%) for episodes treated with a parenteral β-lactam and vancomycin, respectively ( P = 0.015). S. lugdunensis is increasingly being recognized as a cause of PJIs. The majority of the isolates lacked mecA . Episodes treated with a parenteral β-lactam antibiotic appear to have a more favorable outcome than those treated with parenteral vancomycin.

The purpose of this study was to evaluate a magnetic resonance imaging (MRI) compatible knee positioning device to aid in minimizing intratechnologist and intertechnologist differences of minimum joint space width (JSW) measurements. Five subjects were scanned by two separate technologists, with and without an MRI-compatible positioning device. A semi-automated program calculated the minimum JSW of the tibiofemoral and patellofemoral joints. The scan-to-scan repeatability was evaluated from measurements between serial scans without subject repositioning, and the intratechnologist and intertechnologist repeatabilities were evaluated when the subject was removed from the magnet and repositioned by an individual technologist. The root mean square (RMS) error of the JSW measurements was also calculated. All measures of scan-to-scan repeatability and intratechnologist repeatability were unchanged with the MRI-compatible positioning device. The intertechnologist repeatability decreased from 0.70 to 0.42 mm, and the RMS error was significantly reduced ( P = 0.0006) from 0.26 to 0.15 mm for the tibiofemoral joint. The variability of patellofemoral JSW measurements increased when using the positioning device; however, the increases were not statistically significant. The intertechnologist repeatability increased from 1.55 to 1.79 mm, and the RMS error increased from 0.58 to 0.73 mm. The MRI-compatible positioning device was successful at reducing JSW measurement variability at the tibiofemoral joint. The increase in measurement variability at the patellofemoral joint may be due to local incongruities of the articular surfaces. An MRI-compatible positioning device may be beneficial for quantitative longitudinal studies evaluating knee joint health.

Objective: To determine apolipoprotein E (APOE)-ε4 and -ε2 frequencies and risk of mild cognitive impairment (MCI) and dementia in Shanghai, China. Methods: A total of 34 MCI and 34 dementia cases were recruited from an urban Memory Disorders Clinic and 32 controls were recruited from a residential community served by the clinic. Apolipoprotein E was genotyped using standard methods. Results: Among controls, frequencies were ε2, 0.11; ε3, 0.84; and ε4, 0.05; among MCI, 0.05, 0.77, and 0.18; and for dementia, 0.02, 0.84, and 0.15, respectively. In education-adjusted models, the odds ratio (OR) = 5.6 for dementia (95% CI = 1.09-29.3) and 4.7 for MCI (95% CI = 0.90-25.2) associated with any ε4 allele. The ε2 allele was inversely associated with dementia (OR = 0.12, 95% CI = 0.013-0.997) and MCI (OR = 0.38, 95% CI = 0.08-1.61). Conclusions: APOE-ε4 increases and -ε2 decreases the risk of dementia vs normal cognition. Similar trends were observed for amnestic mild cognitive impairment (aMCI).

Abstract Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-α2(I) chain of type 1 procollagen. The isolated periosteal cells were incubated with 1 nM [3H]testosterone ([3H]T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. [3H]5α-dihydrotestosterone ([3H]DHT) was not detected in extracts of periosteal cell incubations. In contrast, [3H]DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5α-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT.

Abstract To determine if bone cells produce interleukin-1β (IL-1β), a potent bone resorption-stimulating agent, we studied well-characterized, nearly homogeneous cultures of normal human osteoblast-like (hOB) cells. With four strains of such cells, vehicle-treated cultures produced minimal IL-1β (mean ± SEM, 1.3 ± 0.3 pg/ml per 106 cells per 24 h) and showed dose-dependent (r = 0.99) increases to 2.2 ± 0.7, 5.0 ± 0.9, or 17.8 ± 6.7 pg/ml, respectively, after treatment with lipopolysaccharide (LPS) at 3, 10, or 30 μg/ml (for increases after 10 and 30 μg/ml treatments, P &lt; 0.05). After treatment with tumor necrosis factor α (TNF-α at 10 U/ ml, IL-1β increased to 16.2 * 3.7 pg/ml (P &lt; 0.05). Neither 17β-estradiol nor bovine parathyroid hormone(1–34) (each at 10 nM), alone or in combination with LPS or TNF-α, affected IL-1β release. Northern blot analysis of total cellular RNA preparation revealed a single hybridization band at 1.9 kb when probed with a partially deleted cDNA for human IL-1β. The steady-state IL-1β mRNA levels showed a significant increase with LPS treatment and a lesser increase with TNF-α treatment in hOB cells. Moreover, TNF-α produced an even greater increase in IL-1 mRNA in HOBIT cells, a well-differentiated clonal cell line derived from normal hOB cells transfected with the SV40 large T antigen. We conclude that human cells of the osteoblast lineage produce IL-Iβ in response to well-recognized stimuli for IL-1 release from responsive tissue. Therefore, IL-1 may play an important role in the local regulation of bone remodeling.

Abstract Although osteoblasts contain estrogen receptors, it is unclear whether estrogen has direct effects on osteoblast proliferation and differentiation. We evaluated the effects of 17β-estradiol treatment (1 pM to 10 nM) on the proliferation and differentiation of cultured normal adult human cells that expressed many of the phenotypic characteristics and hormonal sensitivities of mature osteoblasts (hOB cells). Treatment of hOB cells with estradiol for as long as 144 h did not affect the rate of DNA synthesis and had minimal, if any, effects on differentiated function. Whereas alkaline phosphatase activity was increased by nearly twofold (P &lt; 0.01) when the hOB cells were treated with 1 nM 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], treatment with estradiol had no effect when given alone and did not affect the cells' response to 1,25-(OH)2D3. Similarly, the release of bone gla protein (BGP, osteocalcin) was induced by treatment with 1,25-(OH)2D3 (P &lt; 0.05), but estradiol treatment did not affect this response. Cellular levels of mRNA for alkaline phosphatase and BGP were not altered by estradiol treatment. We conclude that estradiol treatment does not have major effects on the growth or differentiation of cultured hOB cells. These results are consistent with previous observations in vivo that indicate estrogen acts principally to decrease bone resorption, not to modulate its formation.

Abstract A new bone cell line was established by transfecting normal adult human osteoblast-like (hOB) cells, derived from a 68-year-old woman, with the plasmid pSV3 neo. The plasmid included coding sequences and promotors for the large and small T antigens of the SV40 virus as well as resistance to the antibiotics neomycin and G418. A single antibiotic-resistant colony was located and cloned. Large tumor antigen production in the clonal cell line was confirmed by indirect immunofluorescence study. Treatment with 1,25-dihydroxy-vitamin D3 increased steady-state concentrations of protein and mRNA for osteocalcin and for alkaline phosphatase. Northern blot analyses also demonstrated the presence of mRNAs for α(I)-procollagen, osteopontin 1a, transforming growth factor β, and interleukin-1β. The plasma membrane calcium pump and osteonectin were identified by immunocytochemical analysis. These cells produced a matrix that mineralized when β-glycerophosphate was added to their cultures. As assessed by functional receptor assays, both estrogen and androgen receptors were present and functional, although at low concentrations. Treatment with parathyroid hormone did not stimulate adenylate cyclase activity. Thus, these cells are a well-differentiated, steroid-responsive clonal cell line that closely approximates the phenotype of the mature osteoblast. They should serve as an excellent model for the study of osteoblast biology.

Abstract Therapy-related myelodysplastic syndromes (t-MDSs) and acute myeloid leukemia (t-AML) have a poor prognosis with conventional therapy. Encouraging results are reported after allogeneic transplantation. We analyzed outcomes in 868 persons with t-AML (n = 545) or t-MDS (n = 323) receiving allogeneic transplants from 1990 to 2004. A myeloablative regimen was used for conditioning in 77%. Treatment-related mortality (TRM) and relapse were 41% (95% confidence interval [CI], 38-44) and 27% (24-30) at 1 year and 48% (44-51) and 31% (28-34) at 5 years, respectively. Disease-free (DFS) and overall survival (OS) were 32% (95% CI, 29-36) and 37% (34-41) at 1 year and 21% (18-24) and 22% (19-26) at 5 years, respectively. In multivariate analysis, 4 risk factors had adverse impacts on DFS and OS: (1) age older than 35 years; (2) poor-risk cytogenetics; (3) t-AML not in remission or advanced t-MDS; and (4) donor other than an HLA-identical sibling or a partially or well-matched unrelated donor. Five-year survival for subjects with none, 1, 2, 3, or 4 of these risk factors was 50% (95% CI, 38-61), 26% (20-31), 21% (16-26), 10% (5-15), and 4% (0-16), respectively (P < .001). These data permit a more precise prediction of outcome and identify subjects most likely to benefit from allogeneic transplantation.