Heat Induced Processing of Cellblocks with Significant Reduction in Overall Turn Around Time

Introduction

Cellblock (CB) with immunohistochemistry (IHC) is practically indispensable in the diagnostic workup of serous effusions; however, CB requires a minimum of 15-20 h for routine histopathological processing. A reduction in processing time can expedite a faster diagnosis.

Aim

This study was undertaken to evaluate the utility of the heat-induced CB (HICB) technique.

Material and Methods

Two sets of agar-embedded CBs were processed from 50 effusion samples. CBs were further processed by conventional and rapid methods. Conventional CBs (CCB) were processed in a histoprocessor, whereas rapid CB was processed in a heated water bath with an agitation facility. For HICB processing, dehydration and clearing were performed at 50°C followed by paraffin wax impregnation at 65°C temperature. From both CBs, sections of 5 um thickness were cut and stained with hematoxylin and eosin (H and E). Cell morphology, cost, and time were compared between the two methods. The feasibility of IHC was attempted in a few cases.

Results

HICB was completed within 4.30 h compared with CCB. Diagnoses on both CBs were concordant in all the cases. Incomplete dehydration was noted in six (12%) cases, but the diagnosis was not compromised. No additional cost was involved in HICB. On IHC, both HICB and CCB exhibited equivalent expression.

Conclusions

HICB is a rapid, innovative, simple, and cost-effective technique and expedites faster diagnosis. It does not require any advanced equipment.

Heat-induced formation of N,N-dimethylpiperidinium (mepiquat) in Arabica and Robusta coffee

N,N-dimethylpiperidinium (mepiquat) is a new process-induced compound formed from natural constituents during the cooking process. Mepiquat was first found in coffee and cereal products, but its formation mechanism in coffee is still unclear. In the current study, Arabica and Robusta coffee beans were roasted at different temperatures (215, 220, and 230 °C) to study the effect of roasting process on mepiquat formation. The highest mepiquat content, 1,020 µg/kg, was found in dark roast (230 °C) Indonesia Wahana, while 430 µg/kg of mepiquat was detected in medium roast (220 °C) Vietnam Robusta. At the same roasting temperature, higher level of mepiquat was observed in Arabica than in Robusta. In both species, substances related to mepiquat formation, including betaine, choline, trigonelline, lysine, carnitine, pipecolic acid (PipAc), pipecolic acid betaine (PipBet), were also detected. The lysine-based Maillard reaction and decarboxylation in Arabica and Robusta promoted mepiquat formation through the degradation of choline and trigonelline, and the formation of intermediate products. Results from both the model system and selected commercial beans showed that choline and trigonelline had a significant correlation (P < 0.01) with mepiquat formation in Arabica. PRACTICAL APPLICATION: Mepiquat is considered as a new process-induced compound resulting from typical roasting conditions, but its formation mechanism in coffee is still unclear. This work demonstrates the formation mechanism of mepiquat by many precursor substances contained in Arabica and Robusta. It is very important to figure out how mepiquat is ''naturally" present in daily diets, especially in those processed at high temperatures.

Heat-Induced Discoloration of Chromophore Structures in Eucalyptus Lignin

The color changes corresponding to chromophore structures in lignin caused by exposure of Eucalyptus (Eucalyptus grandis and E. urophylla) to heat were investigated. Eucalyptus wood powders were heat treated under saturated steam atmospheres for 10 h at 110 °C, 130 °C and 150 °C. The lignin was isolated before and after heat treatment. The physicochemical properties of the lignin and changes in chromophore structures during heat treatment was evaluated through wet chemical analysis, Fourier transform infrared spectroscopy (FTIR), diffuse reflectance ultraviolet-visible spectroscopy (DRUV-Vis), gel permeation chromatography (GPC), X-ray photoelectron spectroscopy (XPS) and ¹³C Cross polarization magic angle spinning nuclear magnetic resonance (¹³C CPMAS NMR). Wood color darkened and reddened with the increase in pressure and temperature. Depolymerization and dehydration reactions occurred via demethoxylation with heat treatment in saturated steam at 110 °C or 130 °C. Lignin condensed to form insoluble compounds after heat treatment in saturated steam at 150 °C. G units increased and S units decreased through demethylation during heat treatment, as revealed by FTIR and ¹³C-NMR analysis.

Management of heat-induced bone necrosis following thermal removal of gutta-percha

Many endodontically treated teeth require a post to improve the retention of the coronal restoration, which necessitates removal of the coronal part of the gutta-percha from the canal by thermal method, among other techniques. However, this technique carries the risk of heat conduction to the attachment unit of the periodontium and infliction of permanent damage especially in cases where the remaining root's dentin walls are thin. The overall objective of this article is to report on the clinical manifestations, histologic description, and periodontal management of three cases of heat-induced damage following thermal removal of gutta-percha.