Validation of a novel alcohol-free preservative solution in comparison with conventional prefixation on quality of serous body fluid smears.

BACKGROUND: We describe a novel alcohol-free preservative composed of glucose, mannitol, disodium hydrogen orthophosphate, thymol, and distilled water (glucose-mannitol-disodium dihydrogen orhtophosphate-thymol [GMDT] preservative) in appropriate proportion as an alternative to alcohol prefixation (APF) of body fluids. OBJECTIVES: To assess the cytomorphologic preservation and staining quality of serous body fluid smears generated by GMDT preservative and compare it with smears processed by standard 50% APF. METHODOLOGY: The study comprised 151 effusion samples. Each sample was equally divided into four tubes. Equal volumes of APF and GMDT preservatives were added to the first two tubes and left at room temperature for 24 h. Similarly, the corresponding preservatives were added to the third and fourth tubes and stored for 48 h. Two smears were prepared from the centrifuged sediments of each tube (all four tubes) and stained with May-Grünwald Giemsa and Papanicolaou (Pap) stains. Using a three-tiered scoring system, the smear examination was blinded to assess the extent of cellular preservation and the staining quality by two cytotechnologists and two cytopathologists. Statistical analysis was performed by STATA 16.0. RESULTS: Samples processed with the GMDT preservative at 24 h showed better cytoplasmic preservation and smear background, while nuclear features and staining quality showed no difference between the two preservatives. Mild cytoplasmic and nuclear degenerative changes were noted with the GMDT at 48 h, while all four parameters remained similar with APF at 24 and 48 h. CONCLUSIONS: The newly developed alcohol-free, GMDT preservative, could be a feasible and cost-effective alternative to 50% APF, preferably when samples are processed within 24 h.

Utility of the Growth Differentiation Factor-15 in the Differential Diagnosis of Follicular-Patterned Lesions of the Thyroid on Cytopathologic and Histopathologic Samples.

Background Follicular-patterned lesions are a major gray zone in thyroid cytopathology. The recently introduced 2022 World Health Organization (WHO) classification emphasizes the importance of genetic alterations in thyroid neoplasms with the introduction of certain newer terminologies that are expected to cause remarkable changes in cytopathologic and histopathologic reporting. Although molecular assays such as the Afirma gene expression classifier and the ThyroSeq are already in use, there has been an ongoing search for further reliable molecular markers. The growth differentiation factor-15 (GDF-15) is one among them. This study aimed to determine the diagnostic utility of GDF-15 mRNA expression in frozen tissue and fine-needle aspiration (FNA) samples from follicular-patterned thyroid lesions and neoplasms. Methodology The real-time quantitative polymerase chain reaction was performed on 75 frozen tissue and FNA samples each from 19 cases of follicular thyroid hyperplasia (FTH), 10 nodular goiters (NGs), 17 follicular thyroid adenomas (FTAs), eight follicular thyroid carcinomas (FTCs), 12 follicular variant of papillary thyroid carcinomas (FVPTCs), and nine classic papillary thyroid carcinomas (CPTCs) that were diagnosed according to the 2017 WHO classification of thyroid neoplasms. The GDF-15 mRNA expression in all these cases was assessed and compared with the control thyroid tissue samples. One-way analysis of variance and the Kruskal-Wallis test were performed using GraphPad Prism 8 software to determine the significance of differences in the GDF-15 mRNA levels among various thyroid lesions. Results A higher GDF-15 mRNA expression was noted in the malignant thyroid neoplasms including FTC, FVPTC, and CPTC in comparison to FTA, with a fold change between the malignant and benign groups being more than 244.18 times. A difference in the fold change was noted between FTH and FTA with an increase in GDF-15 mRNA level in the latter, which was statistically not significant. Conclusions The fact that GDF-15 mRNA was studied both on fine-needle aspiration cytologic and the frozen tissue material and that the majority of the lesions studied were follicular-patterned establishes the GDF-15 as a potential marker not only for diagnosing malignant thyroid neoplasms of the follicular epithelium but also in distinguishing benign and malignant follicular-patterned neoplasms of the thyroid.

Comparison of the quality of the microwave cell-block method with the conventional cell-block method in processing body fluid samples.

INTRODUCTION: Conventional cell blocks (CCB) prepared from cytological specimens are very useful but the method is relatively time-consuming. Suitable modifications in cell-block techniques are beneficial for improving the turnaround time. We share our experience of a rapid microwave cell-block (MCB) technique. AIM AND OBJECTIVES: To study the quality of routine and immunohistochemical (IHC) staining of cell-block sections from serous body fluids prepared by the MCB technique compared with the CCB technique. METHOD: A total of 177 serous body fluid samples were processed by routine centrifugation technique, and the sediments were used for cell-block preparations by both conventional and rapid microwave methods. Cell-block sections were stained with haematoxylin and eosin stain. Haematoxylin and eosin staining quality was analysed using three parameters (cellularity, morphology and staining intensity). IHC for epithelial membrane antigen and calretinin were also performed, and the quality of staining was evaluated on 62/177 samples. Results were analysed using appropriate statistical tests. RESULTS: The time taken for processing cell blocks by the MCB method was 1 hour and 18 minutes compared to 13 hours and 45 minutes by CCB. The quality of sections by both methods showed good agreement for cellularity and intensity of staining, and moderate agreement for morphology. A 100% concordance was noted for distinguishing benign and malignant samples on morphology as well as with IHC stain results. CONCLUSION: Although the techniques are comparable in terms of quality of routine and IHC staining, we recommend using the MCB technique due to its short turnaround time.

Soil-transmitted helminth eggs assessment in wastewater in an urban area in India.

Water quality and sanitation are inextricably linked to prevalence and control of soil-transmitted helminth infections, a public health concern in resource-limited settings. India bears a large burden of disease associated with poor sanitation. Transformative onsite sanitation technologies are being developed that feature elimination of pathogens including helminth eggs in wastewater treatment. We are conducting third-party testing of multiple sanitation technology systems in Coimbatore (Tamil Nadu) India. To ensure stringent testing of the pathogen removal ability of sanitation technologies, the presence of helminth eggs in wastewater across the town of Coimbatore was assessed. Wastewater samples from existing test sites as well as desludging trucks servicing residential and non-residential septic tanks, were collected. The AmBic methodology (based on washing, sieving, sedimenting and floating) was used for helminth egg isolation. We tested 29 different source samples and found a 52% prevalence of potentially infective helminth eggs. Identification and enumeration of helminth species is reported against the septage source (private residential vs. shared toilet facility) and total solids content. Trichuris egg counts were higher than those of hookworm and Ascaris from desludging trucks, whereas hookworm egg counts were higher in fresh wastewater samples. Surprisingly, no correlation between soil transmitted helminth eggs and total solids was observed.

Characterization of fecal sludge as biomass feedstock for thermal treatment in the southern Indian state of Tamil Nadu.

Background: Transformative sanitation technologies aim to treat fecal sludge (FS) by thermal processes and recover resources from it. There is a paucity of data describing the relevant properties of FS as viable feedstock for thermal treatment in major geographical target areas, such as India. Methods: This study characterized FS collected from septic tanks in two cities located in the Indian southern state of Tamil Nadu. FS samples were obtained at the point of discharge from trucks in Tiruppur (n=85 samples) and Coimbatore (n=50 samples). Additionally, biosolids obtained from sewage treatment plants (STP) in the cities of Coimbatore and Madurai were characterized. Total solids (TS) were measured, and proximate and ultimate analysis were conducted according to methods used by the fuel industry. Additionally, the ash content was analyzed for heavy metal using standard methods. Results: The average higher heating value (HHV) across all FS samples in Tiruppur (13.4 MJ/kg) was significantly higher than in Coimbatore (5.4 MJ/kg), which was partially attributed to the high ash content of 69% in the latter samples.  The HHV of the biosolids samples ranged from 10 to 12.2 MJ/Kg. The average total solids (TS) content for FS was 3.3% and 2.0% for Tiruppur and Coimbatore respectively, while the median TS content for the two cities was 2.3% and 1.2%. The heavy metal content of the ash was found to be below the thresholds for land disposal. Conclusions: This is one of the first studies that has systematically characterized the calorific and mineral content of septage and biosolids in several cities in India. We expect these data to serve as input data in the design of thermal processes for fecal sludge treatment.