Background: Oral squamous cell carcinoma (OSCC) is a multifactorial malignant epithelial neoplasm. Tumor clearance at the surgical margins in OSCC is a critical factor which strongly influences both the local recurrence and overall survival rate. A quick and accurate intraoperative diagnostic procedure can make a significant difference to the survival rate. Touch imprint cytology (TIC) has commonly been used in the past for the diagnosis of tumors and the detection of sentinel lymph node metastasis. It is routinely applied for intraoperative margin analysis of breast lumpectomy specimens, where it has been proven to have a good success rate. The effectiveness and reliability of TIC in the intraoperative margin evaluation of OSCC, however, has not been established so far. Objective: To investigate the diagnostic accuracy of the intraoperative TIC technique for assessing surgical margins in OSCC in comparison to paraffin-embedded hematoxylin and eosin-stained sections. Materials and Methods: Thirty previously untreated, biopsy-proven OSCC patients undergoing surgical treatment between December 2008 and September 2010 were included. Patients diagnosed with histological variants of squamous cell carcinoma (SCC) or recurrent tumor were excluded. Three hundred forty-eight touch imprint slides were prepared from 174 margins of 30 resected tumor specimens. Imprints from tumor proper were taken as positive controls. The slides were reported as positive, negative or suspicious for tumor. After all cytological interpretation was completed, the results were compared with the corresponding histological diagnosis. Results: This pioneer study showed that TIC has an overall accuracy of 83%, sensitivity of 91.1%, specificity of 74.4%, positive predictive value of 79.2% and a negative predictive value of 88.6%. The false-positive margins evaluated by TIC were 43 (12.3%) and the false-negative ones were 16 (4.6%). Conclusion: TIC is a quick, simple, inexpensive, highly accurate and reliable intraoperative technique to assess surgical margins in SCC of the oral cavity.

Background Among many drugs that hold potential in COVID-19 pandemic, chloroquine (CQ), and its derivative hydroxychloroquine (HCQ) have generated unusual interest. With increasing usage, there has been growing concern about the prolongation of QTc interval and Torsades de Pointes (TdP) with HCQ, especially in combination with azithromycin. Aims This meta-analysis is planned to study the risk of QTc prolongation and Torsades de pointes (TdP) by a well-defined criterion for HCQ, CQ alone, and in combination with Azithromycin in patients with COVID-19. Methods A comprehensive literature search was made in two databases (PubMed, Embase). Three outcomes explored in the included studies were frequency of QTc > 500 ms (ms) or ΔQTc > 60 ms (Outcome 1), frequency of QTc > 500 ms (Outcome 2) and frequency of TdP (Outcome 3). Random effects method with inverse variance approach was used for computation of pooled summary and risk ratio. Results A total of 13 studies comprising of 2138 patients were included in the final analysis. The pooled prevalence of outcome 1, outcome 2 and outcome 3 for HCQ, CQ alone with or without Azithromycin were 10.18% (5.59–17.82%, I 2 – 92%), 10.22% (6.01–16.85%, I 2 – 79%), and 0.72% (0.34–1.51, I 2 – 0%) respectively. The prevalence of outcome 2 in subgroup analysis for HCQ and HCQ + Azithromycin was 7.25% (3.22–15.52, I 2 – 59%) and 8.61% (4.52–15.79, I 2 – 76%), respectively. The risk ratio (RR) for outcome 1 and outcome 2 between HCQ + Azithromycin and HCQ was 1.22 (0.77–1.93, I 2 – 0%) & 1.51 (0.79–2.87, I 2 – 13%), respectively and was not significant. Heterogeneity was noted statistically as well clinically (regimen types, patient numbers, study design, and outcome definition). Conclusion The use of HCQ/CQ is associated with a high prevalence of QTc prolongation. However, it is not associated with a high risk of TdP.

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The Oxford-Astra Zeneca COVID 19 vaccine (AZD1222 or ChAdOx1) is an important part of the global vaccine roll-out against SARS-CoV-2, and a locally manufactured version (Covishield by Serum Institute, Pune, India) is the most commonly used vaccine in India. The vaccination program started in January 2021 and here we report effectiveness of the first dose of Covishield in generating antibody response and its kinetics. We further report differences in the quantitative antibody response amongst individuals who had pre-existing antibodies to SARS CoV2 and those who did not. In a group of 135 healthcare workers administered Covishield, we measured antibodies to SARS-CoV-2 directed against the spike protein (S-antigen) using Elecsys Anti-SARS-CoV-2 S quantitative antibody detection kit (Roche Diagnostics) at days 0, 7, 14, and 28. In 44 subjects (32.5%) who had already developed antibodies to SARS-CoV-2 at day 0 (before immunization), it was observed that antibody response was significantly higher at each time point, with the maximum increase seen between days 0 and 7. In contrast the sero-negative group (n=91) started developing antibody response only after 14 days or later. Three sero-negative individuals did not develop any antibody response even at day 28 of vaccination. It is noted that median antibody response at 28 days in seronegative subjects was similar to that of seropositive subjects at baseline (day 0) and was on a rising trajectory. Our data suggests that ChAdOx1 is highly immunogenic, particularly so where previous SARS CoV2 antibody-response is established. Given the high background seropositivity in India, this may be useful in determining optimal timing of the second dose during mass immunization within the constraints of vaccine supply and administration.

Immunization is expected to confer protection against infection and severe disease for vaccines while reducing risks to unimmunized populations by inhibiting transmission. Here, based on serial serological studies of an observational cohort of healthcare workers, we show that during a Severe Acute Respiratory Syndrome -Coronavirus 2 Delta-variant outbreak in Delhi, 25.3% (95% Confidence Interval 16.9-35.2) of previously uninfected, ChAdOx1-nCoV19 double vaccinated, healthcare workers were infected within less than two months, based on serology. Induction of anti-spike response was similar between groups with breakthrough infection (541 U/ml, Inter Quartile Range 374) and without (342 U/ml, Inter Quartile Range 497), as was the induction of neutralization activity to wildtype. This was not vaccine failure since vaccine effectiveness estimate based on infection rates in an unvaccinated cohort were about 70% and most infections were asymptomatic. We find that while ChAdOx1-nCoV19 vaccination remains effective in preventing severe infections, it is unlikely to be completely able to block transmission and provide herd immunity.

Background: Eradication of malignant tumors at the primary site with oncological safe margin is a critical requirement for obtaining better survival rate and less recurrence. Touch imprint cytology (TIC) has proven itself as a quick, simple, inexpensive, highly accurate and reliable intraoperative technique to assess surgical margins in squamous cell carcinomas of the oral cavity. However, it is still unclear how the mode of excision, i.e. by scalpel (SC) and electrocautery (EC), or the method of staining, i.e. Papanicolaou (PAP) and cytohaem, affect the diagnostic accuracy of TIC. Objective: To study the influence of confounding factors like mode of excision (EC/SC) and staining (PAP/cytohaem) on the diagnostic accuracy of intraoperative TIC technique for assessing surgical margins in oral squamous cell carcinoma in comparison to paraffin-embedded HE-stained sections. Materials and Methods: Thirty patients underwent surgical treatment for primary oral squamous cell carcinoma. Three hundred and forty-eight touch imprint slides were prepared from 174 margins of 30 resected tumor specimens. Two adjacent tissues from the margin to be evaluated were imprinted to observe differences between surfaces excised by EC and SC. The set of imprint from each margin tissue was stained with PAP and cytohaem. The TIC results of 180 EC-excised margins and 168 SC-excised margins were compared. Results of 174 imprints stained with RAPID-PAP were compared to their counterpart comprising of 174 cytohaem-stained imprints. The slides were diagnosed as positive, negative or suspicious for tumor. Finally, TIC results were checked against their respective histopathological sections. Results: No statistically significant difference was found between the results of imprints from EC/SC-excised margins (Z = 0.44, p = 0.70) or the imprints stained with PAP/cytohaem (Z = 0.44, p = 0.70). Conclusion: Confounding factors like mode of excision and staining procedure do not significantly influence the results of imprint cytology.

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