Pitfalls in the echocardiographic diagnosis of intracardiac and extracardiac masses

Transthoracic and transesophageal two-dimensional (2-D) echocardiography remain the procedures of choice for evaluating cardiac mass lesions. Potential errors in diagnosis can be made, however, if the mass lesion's size, shape, mobility, and attachment to other cardiac structures are not clearly delineated. Usually a left atrial myxoma arises from the interatrial septum at the level of the fossa ovalis. Pitfalls in diagnosis occur when the tumor size is very small, or its attachment site is atypical or ill-defined. Atrial thrombi classically reside in an atrial appendage, but can also form in the body of the left atrium. The presence of atrial fibrillation rhythm, enlarged atrial chamber, prosthetic mitral/tricuspid valves, stenotic mitral/tricuspid valves, low cardiac output state, and spontaneous atrial contrast echoes are all features that favor the mass in question being a thrombus. Ventricular thrombi usually occur with poorly functioning ventricles. The diagnosis of ventricular thrombus should be made with great caution if the systolic function is normal, or if the mass has a band or thread-like appearance. A thorough knowledge of normal anatomical variants that can mimic pathological lesions is also important for reaching a correct diagnosis. Last but not least, as in all testing modalities, the patient's clinical picture should be correlated with the echocardiographic findings.     

Angiogenic factors stimulate mast-cell migration

Mast cells accumulate at sites of angiogenesis. The factor(s) that control mast-cell recruitment at these sites have yet to be defined. We sought to determine if angiogenic factors result in mast-cell chemotaxis. In this study, we observed that platelet-derived growth factor-AB (PDGF-AB), vascular endothelial cell growth factor (VEGF), and basic fibroblast growth factor (bFGF) each cause directed migration of murine mast cells at picomolar concentrations, with a typical bell- shaped dose-response curve. Another potent angiogenic factor, platelet- derived endothelial cell growth factor (PD-ECGF), appears to promote chemokinesis of mast cells, whereas tumor necrosis factor-alpha, a weak angiogenic factor, is less robust but still functions as a mast cell chemotactic factor. Epidermal growth factor (EGF), a growth factor with minimal angiogenic properties, was ineffective as a mast cell chemotactic factor. A checkerboard analysis confirmed the directional chemotactic response of PDGF-AB, VEGF, and bFGF, while indicating the chemokinetic response induced by PD-ECGF. Cross-desensitization of growth-factor-induced directed migration was observed between PDGF-AB and bFGF, and also between PDGF-AB and PD-ECGF. Tyrosine kinase- inhibitor genistein effectively dampened the chemotactic responses, whereas pertussis toxin had no effect. In summary, our findings suggest that factors known to act on endothelial cells and stimulate neovascularization may simultaneously serve to recruit mast cells to these sites. The local accumulation of mast cells is believed to facilitate new vessel formation through complex cell:cell interactions.     

T-cell receptor delta/alpha rearrangements in lymphoid neoplasms

Rearrangements within the T-cell receptor (TCR)delta/alpha locus were analyzed in a wide variety of lymphoid neoplasms by eight DNA probes specific for TCR J delta, J alpha and C alpha segments. In all 11 T- cell malignancies, rearrangement and/or deletion of TCR delta was detected irrespective of the stage of maturation of the tumor. The organization of TCR delta correlated with the phenotype of the tumor: In "prethymic" T-cell acute lymphocytic leukemia (ALL), TCR delta was the only TCR gene to be rearranged. More mature T cell malignancies expressing CD4 together with CD3 showed deletion of both alleles of TCR delta, suggestive of TCR V alpha-J alpha rearrangement. All 43 B-cell tumors expressing surface immunoglobulin (sIg), including two cases of adult B-cell ALL, had germline configuration of TCR delta/alpha. In contrast, all 17 B-cell precursor ALLs (null, common, and pre-B-cell ALLs) had rearrangement and/or deletion of TCR delta/alpha. A single case of "histiocytic" lymphoma also showed biallelic deletion of TCR delta. Oligoclonal rearrangements of Ig and TCR genes were observed in two cases of B-cell precursor ALL and in one case of T-cell lymphoblastic lymphoma. Patterns of such "aberrant" TCR rearrangement were similar to those observed in T-lineage malignancies. In particular, seven of eight cases of B-cell precursor ALL and the histiocytic lymphoma which demonstrated biallelic TCR delta deletion, (suggestive of a V alpha-J alpha rearrangement) had clonal TCR beta rearrangement. These data support the hypothesis that supposedly aberrant rearrangements of the TCR genes may follow the same developmental controls as found in T-cell differentiation, despite the lack of evidence for further commitment to the T-cell lineage. TCR delta rearrangement is a useful marker of clonality of immature T-cell tumors which may have only this gene rearranged but is not specific to the T-cell lineage.     

Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo

Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38- cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38- subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38- cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset.     

Electrochemical oxidation of As(iii) on Pd immobilized Pt surface: kinetics and sensing performance

Pd nanoparticles were electrochemically immobilized on a Pt surface in the presence of sodium dodecyl sulfate (SDS) molecules to study the electrokinetics of arsenite oxidation reactions and the corresponding sensing activities. The X-ray photoelectron spectroscopy (XPS) analysis showed that on the Pt surface, Pd atoms exist as adatoms and the contents of Pd(0) and Pd(ii) were 75.72 and 24.28 at%, respectively, and the particle sizes were in the range of 61–145 nm. The experimental results revealed that the catalytic efficiency as well as the charge transfer resistance (at the redox potential of the Fe(ii)/Fe(iii) couple) increased in the order of Pt < Pt–Pd < Pt–Pd_sds. A Pt–Pd_sds electrode exhibited an open circuit potential (OCP) of 0.65 V in acidic conditions; however, when 50.0 mM NaAsO₂ was present, the OCP value shifted to 0.42 V. It has been projected that the As(iii) oxidation proceeds using a sequential pathway: As(iii) → As(iv) → As(v). After optimization of the square wave voltammetric data, the limits of detection of As(iii) were obtained as 1.3 μg L⁻¹ and 0.2 μg L⁻¹ when the surface modification of the Pt surface was executed with Pd particles in the absence and presence of the SDS surfactant, respectively. Finally, real samples were analyzed with excellent recovery performance.

Amplification of true surface area can be improved when Pd particles are deposited on a substrate in the presence of sodium dodecyl sulfate (SDS) surfactant. In acidic medium, As(iii) undergoes a two-step oxidation process.     

Salbutamol in acute organophosphorus insecticide poisoning – a pilotdose-response phase II study

Background: Treatment of acute organophosphorus (OP) insecticide poisoning is difficult, with many patients dying despite best care. Pre-clinical studies have shown benefit from salbutamol, possibly due speeding alveolar fluid clearance or reducing bronchoconstriction. In this small pilot dose-response study, we aimed to explore whether addition of nebulized salbutamol to standard care might improve resuscitation.

Methods: We performed a single-blind phase II study comparing the effect of two different doses of nebulized salbutamol versus saline placebo, in addition to standard treatment. Primary outcome was oxygen saturations over the first 60?min of resuscitation; secondary outcomes included heart rate, incidence of dysrhythmias, time to ‘atropinization’, atropine dose required, and mortality.

Result: Seventy-five patients were randomized to receive 5?mg (Salb5, n?=?25) or 2.5mg (Salb2.5, n?=?25) of salbutamol, or saline placebo (NoSalb, n?=?25), by nebulizer. Oxygen saturations did not differ between groups over the first 60?min of resuscitation (median AUC NoSalb: 1376 [95% CI 1282 to 1470], Salb2.5: 1395 [1305 to 1486], Salb5: 1233 [1100 to 1367]; p?=?.9898). Heart rate was also similar across the three arms. Median time to full atropinization, and atropine dose required, were the same for all three arms (NoSalb 15.0 [10–16] min and 12.6 [8.0–13.4] mg, Salb2.5 15.0 [10–16] min and 12.6 [9.3–16.8] mg, and Salb5 15.0 [10–20] min and 12.6 [10.7–20.6] mg; p?=?.4805 and p?=?.1871, respectively). Three (12%) patients died in the Salb2.5 and Salb5 groups and two (8%) in the NoSalb group.

Conclusion: This pilot study, within the limitations of its small size and variation between patients, found no apparent evidence that administration of nebulized salbutamol improved resuscitation of patients with acute OP insecticide self-poisoning. The data obtained provides a basis to design further studies to ultimately test the role of salbutamol in OP insecticide poisoning.     

Extensive suppuration and being overweight are factors associated with the failure of laser treatment for pilonidal disease: lessons from the first French retrospective cohort

Techniques in Coloproctology - The aim of our study was to assess the efficacy of sinus laser therapy (SiLaT) for the treatment of pilonidal disease. All adult patients treated with SiLaT in our...     

Failure of fasting to influence the GIP response to oral glucose in non-obese human subjects

The plasma GIP response to an oral 50 g glucose tolerance test has been compared in eight non-obese human subjects after 12 and 36 h of fasting. Basal plasma GIP and basal plasma insulin concentrations were similar after 12 and 36 h of fasting. Basal blood glucose was lower after 36 h fasting than after 12 h fasting (p less than 0.0125). After 36 h fasting the oral glucose tolerance test stimulated higher blood glucose concentrations at 60, 90 and 120 min (p less than 0.0125) and higher plasma insulin concentrations at similar time points (p less than 0.05), but stimulated plasma GIP concentrations were similar after 12 and 36 h fasts. These findings show that the increased insulinotrophic effect of oral glucose after 36 h fasting in non-obese subjects is not due to an associated augmentation of the glucose-induced GIP response.