The utility of vapor fixation for cell block preparation in fine needle aspiration of malignant lesions of lymph nodes

Cell blocks overcome certain limitations of fine needle aspiration cytology (FNAC), such as study of tissue architecture and application of immunohistochemistry (IHC). The main disadvantage of cell block by conventional method is cell loss. This study compares formaldehyde vapor-fixed cell blocks with conventional formalin-fixed blocks obtained from aspirates of malignant lesions of lymph nodes. Seventy-nine patients with suspected primary or metastatic malignancy in lymph nodes were studied. Cytologic smears were prepared in all the cases. Conventional formalin-fixed cell blocks were made in 34 cases, vapor-fixed cell blocks in 34 cases, and in the remaining 11 cases, both methods were employed. Cell block sections were compared for cellularity, fixation artifacts, morphologic details, and crispness of immunohistochemical staining using defined subjective criteria. Cellular yield was slightly less with vapor-fixed cell blocks in comparison with conventional formalin-fixed cell blocks. Staining artifacts were more frequent with vapor fixation (33.3%) as compared to conventional formalin fixation (20%). Also, vapor fixation required more time (6 h) as compared to conventional formalin fixation (1 h). There was no difference in the two techniques with respect to immunohistochemical staining. Cell blocks prepared by vapor fixation are comparable to conventional formalin-fixed cell blocks.     

Advances in Translational Neuropathic Research: Example of Enantioselective Pharmacokinetic–Pharmacodynamic Modeling of Ketamine-induced Pain Relief in Complex Regional Pain Syndrome

Historically, complex regional pain syndrome (CRPS) was poorly defined, which meant that scientists and clinicians faced much uncertainty in the study, diagnosis, and treatment of the syndrome. The problem could be attributed to a nonspecific diagnostic criteria, unknown pathophysiologic causes, and limited treatment options. The two forms of CRPS still are painful, debilitating disorders whose sufferers carry heavy emotional burdens. Current research has shown that CRPS I and CRPS II are distinctive processes, and the presence or absence of a partial nerve lesion distinguishes them apart. Ketamine has been the focus of various studies involving the treatment of CRPS; however, currently, there is incomplete data from evidence-based studies. The question as to why ketamine is effective in controlling the symptoms of a subset of patients with CRPS and not others remains to be answered. A possible explanation to this phenomenon is pharmacogenetic differences that may exist in different patient populations. This review summarizes important translational work recently published on the treatment of CRPS using ketamine.     

Cytotoxicity of 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT) and analogues in wild type and CYP3A4 stably transfected HepG2 cells

The thiazolidinedione (TZD) ring is a constituent of the glitazones that are used to treat type II diabetes. Liver injury has been reported following chronic glitazone use; however, they do not produce hepatic damage in common laboratory animal species. In contrast, 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT) causes hepatotoxicity in rats. DCPT toxicity is dependent upon the presence of an intact TZD ring and cytochrome P450 (CYP)-mediated biotransformation. To further investigate TZD ring-induced toxicity, DCPT and several structural analogues or potential metabolites were tested in vitro using wild type human hepatoma HepG2 and HepG2 cells stably transfected with the CYP3A4 isozyme. CYP3A4 activity was confirmed by measuring testosterone 6β-hydroxylation. Both cell lines were treated with 0-250 μM of the compounds in Hanks' balanced salt solution. Cell viability was measured after 24 h. DCPT and S-(3,5-dichlorophenyl)aminocarbonyl thioglycolic acid (DCTA) were the most toxic compounds of the series. Furthermore, DCPT was significantly more toxic in transfected cells (LC50=160.2±5.9 μM) than in wild type cells (LC50=233.0±19.7 μM). Treatment with a CYP3A4 inhibitor or inducer attenuated or potentiated DCPT cytotoxicity, respectively. These results suggest that DCPT-induced cytotoxicity in the transfected HepG2 cells is partially dependent on CYP3A4.     

Furan based cyclic oligopeptides selectively target G-quadruplex

We report the binding properties of 18- and 24-membered cyclic oligopeptides developed from a novel furan amino acid, 5-(aminomethyl)-2-furancarboxylic acid, to G-quadruplex. Comparative analysis of the binding data of these ligands with G-quadruplex and double-strand DNA shows that 24-membered cyclic peptides are highly selective for telomeric G-quadruplex structures and thus can be used as a scaffold to target quadruplex structures at the genomic level.     

Inflammatory pseudotumor of the spleen: A rare case diagnosed on FNAC

Inflammatory pseudotumor (IPT) is a rare space‐occupying lesion of unknown etiology that can mimic malignancy on clinic‐radiological and pathological examination. We present a case of IPT of the spleen which was clinically suspected to be malignant. This case was initially suggested accurately on fine needle aspiration (FNA) of the mass and subsequently confirmed on histopathology of the resected specimen. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.     

A Double in vivo Biotinylation Technique for Objective Assessment of Aging and Clearance of Mouse Erythrocytes in Blood Circulation

Summary

We have recently developed a new technique to objectively identify erythrocyte cohorts of defined age in mouse blood. The technique (termed double in vivo biotinylation, DIB) involves an initial biotinylation of all erythrocytes in circulation, followed after a few days by a second biotinylation, at a lower density, that labels the biotin-negative erythrocytes that have entered since the first biotinylation. The proportions of biotin^high, biotin^low, and biotin^negative erythrocytes are enumerated by flow cytometry. The DIB technique allows us to track age-related changes on erythrocyte cohorts (Protocol A), and to simultaneously identify very young and older erythrocyte populations in the blood (Protocol B). Using this technique, we have reexamined: i) the relationship between age and buoyant density of erythrocytes, ii) erythrocyte destruction through a random removal mechanism, and iii) the expression of phosphatidylserine on aging erythrocytes. We have also used the DIB technique to study age-related changes in the expression of various markers like CD47 and CD147 and green autofluorescence in aging erythrocyte populations.KeyWords: Double in vivo biotinylation, Erythrocyte aging, Erythrocyte removal, Mouse blood circulation     

Evaluation of RETRO-Mapping for electrophysiological features including direction of plane activity during atrial fibrillation using multipolar catheters in humans

Introduction

A quantifiable, automated standard of analyzing heart rhythm has long eluded cardiologists due, in part, to the limitations in technology and the ability to analyze large electrogram datasets. In this proof-of-concept study, we propose new measures to quantify plane activity in atrial fibrillation (AF) using our Representation of Electrical Tracking of Origin (RETRO)-Mapping software.

Methods

We recorded 30 s segments of electrograms at the lower posterior wall of the left atrium using a 20-pole double loop catheter (AFocusII). The data were analyzed with the custom RETRO-Mapping algorithm in MATLAB. Thirty second segments were analyzed for number of activation edges, conduction velocity (CV), cycle length (CL), activation edge direction, and wavefront direction. These features were compared across 34 613 plane edges in three types of AF: persistent AF treated with amiodarone (11 906 wavefronts), persistent AF without amiodarone (14 959 wavefronts), and paroxysmal AF (7748 wavefronts). Change in activation edge direction between subsequent frames and change in overall wavefront direction between subsequent wavefronts were analyzed.

Results

All activation edge directions were represented across the lower posterior wall. The median change in activation edge direction followed a linear pattern for all three types of AF with R² = 0.932 for persistent AF treated without amiodarone, R² = 0.942 for paroxysmal AF, and R² = 0.958 for persistent AF treated with amiodarone. All medians and the standard deviation error bars remained below 45° (suggesting all activation edges were traveling within a 90° sector, a criterion for plane activity). The directions of approximately half of all wavefronts (56.1% for persistent without amiodarone, 51.8% for paroxysmal, 48.8% for persistent with amiodarone) were predictive of the directions of the subsequent wavefront.

Conclusion

RETRO-Mapping can measure electrophysiological features of activation activity and this proof-of-concept study suggests that this can be extended to the detection of plane activity in three types of AF. Wavefront direction may have a role in future work for predicting plane activity. For this study, we focused more on the ability of the algorithm to detect plane activity and less the differences between the types of AF. Future work should be in validating these results with a larger data set and comparing with other types of activation such as rotational, collision, and focal. Ultimately, this work can be implemented in real-time for prediction of wavefronts during ablation procedures.