Pulmonary arterial hypertension: noninvasive detection with phase-contrast MR imaging

PURPOSE: To retrospectively identify pulmonary arterial (PA) flow parameters measured with phase-contrast magnetic resonance (MR) imaging that allow noninvasive diagnosis of chronic PA hypertension (PAH). MATERIALS AND METHODS: The study was HIPAA compliant and was approved by the institutional review board; a waiver of informed consent was obtained. Fifty-nine patients (49 female patients; mean age, 46 years; range, 16-85 years) known to have or suspected of having PAH underwent breath-hold phase-contrast MR imaging and right-sided heart catheterization (RHC). The presence of PAH (mean pulmonary artery pressure [mPAP], >25 mm Hg) was confirmed in 42 patients. Parameters, including PA areas, PA strain, average velocity, peak velocity, acceleration time, and ejection time, were measured in each patient by investigators blinded to RHC results. These measurements were correlated with mPAP, systolic pulmonary artery pressure (sPAP), and pulmonary vascular resistance index (PVRI). The diagnostic ability of phase-contrast MR imaging to depict PAH was quantified. Statistical tests included Spearman rho coefficients, receiver operating characteristic curve analysis, and Bland-Altman plots. RESULTS: Results showed average velocity to have the best correlation with mPAP, sPAP, and PVRI (r = -0.73, -0.76, and -0.86, respectively; P < .001). Average velocity (cutoff value = 11.7 cm/sec) revealed PAH with a sensitivity of 92.9% (39 of 42) and a specificity of 82.4% (14 of 17). Sensitivity and specificity for the minimum PA area (cutoff value = 6.6 cm(2)) were 92.9% (39 of 42) and 88.2% (15 of 17), respectively. CONCLUSION: The average blood velocity throughout the cardiac cycle is strongly correlated with pulmonary pressures and resistance.     

Olfaction in dentistry

Oral Diseases (2010) 16 , 221–232 Practitioners of oral medicine frequently encounter patients with complaints of taste disturbance. While some such complaints represent pathological processes specific to the gustatory system, per se, this is rarely the case. Unless taste‐bud mediated qualities such as sweet, sour, bitter, salty, umami, chalky, or metallic are involved, ‘taste’ dysfunction inevitably reflects damage to the sense of smell. Such ‘taste’ sensations as chicken, chocolate, coffee, raspberry, steak sauce, pizza, and hamburger are dependent upon stimulation of the olfactory receptors via the nasopharynx during deglutition. In this paper, we briefly review the anatomy, physiology, and pathophysiology of the olfactory system, along with means for clinically assessing its function. The prevalence, etiology, and nature of olfactory disorders commonly encountered in the dental clinic are addressed, along with approaches to therapy and patient management.     

Prevalence and correlates of septal delayed contrast enhancement in patients with pulmonary hypertension

Using cardiac magnetic resonance, the presence of myocardial delayed contrast enhancement (DCE) has been described in the ventricular septum at the level of the right ventricular insertion points in patients with pulmonary hypertension (PH). The aim of this study was to investigate the prevalence, extent, and correlates of this finding. Septal DCE was evaluated in 55 patients with known or suspected PH of various causes. The extent of DCE was estimated visually with an insertion enhancement score (range 0 to 4) and quantified as DCE mass. The results were correlated with cine magnetic resonance and right-sided cardiac catheterization. Predictors of DCE were investigated using multivariate analysis. PH at rest was present in 42 patients (group 1) and absent in 13 (group 2). DCE was noted in 41 patients (97%) in group 1 and 3 (23%) in group 2 (p <0.0001). The extent of DCE was higher in group 1 than group 2 (median insertion enhancement score 3 vs 0, median DCE mass 8.7 vs 0 g, respectively; p <0.0001 for both). The extent of DCE showed moderate to good univariate correlations (r = 0.5 to 0.73) with pulmonary pressures and with right ventricular volumes, mass, and ejection fractions. In multivariate analysis, systolic pulmonary pressure was the only predictor of DCE. In conclusion, the presence of septal DCE at the right ventricular insertion points is common in PH of different causes, and the level of systolic pulmonary pressure elevation appears to be the main determinant of this finding.     

Biological evaluation of intervertebral disc cells in different formulations of gellan gum‐based hydrogels

Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Surgical versus non-surgical endodontic re-treatment for periradicular lesions

Background : Though success rates of endodontic initial treatment have been improving over the years, persistence of periapical disease is far from being a rare condition. The most common therapeutical options for the re‐treatment of teeth with periapical pathosis are non‐surgical orthograde treatment and surgical treatment. Selection between alternative treatments should be based on assessment of respective benefits (mainly healing) and risks from studies consistent with a high level of evidence. Objectives : To test the null hypothesis of no difference in outcome between surgical and non‐surgical therapy for endodontic re‐treatment of periradicular lesions. Search strategy : The Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE and EMBASE were searched with appropriate search strategies. Handsearching included eight dental journals. The bibliographies of relevant clinical trials and relevant articles were checked for identifying studies outside the handsearched journals. Seven manufacturers of instruments in the field of endodontics or endodontic surgery or both, as well as the authors of the identified randomized controlled trials (RCTs) were contacted in order to identify unpublished or ongoing RCTs. No language restriction was placed. The last electronic search was conducted on 3rd April 2007. Selection criteria : All RCTs about re‐treatment of teeth with periapical pathosis in which both surgical and non‐surgical approaches were used and having a follow up of at least 1 year were considered for the analysis. Data collection and analysis : A quality assessment of the included RCTs was carried out and the authors were contacted for missing information. We independently extracted the data in duplicate. We followed the Cochrane Oral Health Group's statistical guidelines. Main results : Three RCTs were identified, two of them reporting different data from the same clinical study. The risk of bias was judged as moderate for one study and high for the other one. One hundred and twenty‐six cases were followed up for at least 1 year, and 82 had a follow up of 4 years. At the 1‐year follow up the success rate for surgical treatment was slightly better than non‐surgical (risk ratio (RR) 1.13; 95% confidence interval (CI) 0.98 to 1.30). When the follow up was extended to 4 years (only one RCT made it) the outcome for the two procedures became similar. Authors' conclusions : The finding that healing rates can be higher for cases treated surgically as compared to those treated non‐surgically, at least in the short term, is based on two RCTs only. A single RCT reported that in the medium to long term healing rates for the two procedures are very similar. There is currently scarce evidence for a sound decision making process among alternative treatments for the re‐treatment of a periradicular pathosis. More well‐designed RCTs should be performed with follow up of at least 4 years, and with a consistent sample size, to detect a true difference in the long term between the outcomes of the two alternative treatments, if any exist.     

Autoantibodies inhibit interleukin-7-mediated proliferation and are associated with the age-dependent loss of pre-B cells in autoimmune New Zealand Black Mice

Surface IgM+B220+ B cell precursors can be categorized as either leukosialin (CD43/S7) negative (late stage pre-B cells) or positive (pro-B/early pre-B cells). In autoimmune New Zealand Black (NZB) mice, bone marrow small pre-B cells (IgM-CD43-B220+) and pro-B/early pre-B cells (IgM-CD43+B220+) declined significantly with age. In particular, subpopulations of pro-B/early pre-B cells expressing the heat stable antigen (HSA) were found in lower proportions with age. Significant decreases in interleukin-7 (IL-7) colony forming units (CFU) were also seen in NZB mice by 6 to 8 months of age and accompanied alterations in the numbers of pro-B and pre-B cells in bone marrow. Concomitant with reduced numbers of B lineage precursor cells and IL-7 CFU in vivo, NZB mice produced serum IgM antibodies that strongly inhibited IL-7 CFU responses in vitro. Two monoclonal IgM antibodies (5G9, 2F5) derived from LPS stimulated 10-month-old NZB splenocytes recognized pre-B cell surface antigens on both pre-B cell lines and on IL-7 stimulated bone marrow pro-B/pre-B cells. However, these monoclonal antibodies (MoAb) failed to significantly stain ex vivo bone marrow cells. The 5G9 and 2F5 MoAbs also partially inhibited IL-7 CFU in vitro. These results suggest that NZB bone marrow becomes increasingly deficient in B cell precursors and especially in IL-7 responsive pre-B cells with age. IgM serum antibodies and monoclonal IgM antibodies derived from older NZB mice inhibit pre-B cell growth to IL-7. The production of such autoantibodies may interfere with B cell development in aging NZB mice by preventing IL-7-mediated proliferation.