Histological Spectrum of Post Covid Debridement Tissues: Salient Histomorphological Features With Respect to Identification Fungal Elements.

Background: Secondary bacterial and fungal infections in COVID patients have been documented during current pandemic. The present study provides detailed account of histomorphology of debridement tissue received for suspected fungal infections. The primary objective was to determine the morphological characteristics that must be recognized for the identification of fungal hyphae. Methods: The detailed histological examination of debridement tissue was performed. Demographic and clinical findings with treatment provided was recorded. Presence or absence of necrosis and lecocytoclasis was noted. Results: A total of 110 cases of debrided tissues were included in the study. Eosinophilic granular necrosis with lecocytoclasis was observed in 103cases; fungal elements were identified in 89.3% (92/103) of these. Eleven cases where necrosis was observed, strong suspicion of fungus was reported, 6 of them displayed fungus on KOH preparation, 3 on repeat biopsy. However, in 2 of these cases, neither KOH nor repeat biopsies identified the fungus. Mucor with aspergillus was observed in 7 cases and actinomyces in 3. In all these 10 cases dense fungal colonies were evident. In 7 cases careful observation revealed fruiting bodies of aspergillus. Cotton ball appearance of actinomyces was evident. Mucor infection in current disease was so rampant that aseptate ribbon like branching mucor hyphae were evident on H&E sections. Diabetes was significantly associated with fungal infection (97.2%; 70/72; P < .005). 90% [19/21] of the patients who were on room air and diagnosed with fungal infection were diabetic. Conclusions: Eosinophilic granular necrosis with the presence of neutrophilic debris in a case of suspected fungal disease suggests the presence of fungal elements. This warrants processing of the entire tissue deposited for examination, careful observation, application of fungal stains, and repeat biopsy if clinical suspicion is strong. Moreover, uncontrolled diabetes is more frequently associated with secondary fungal infection in COVID patients as compared to oxygen therapy.

Pore-forming toxins in infection and immunity.

The integrity of the plasma membranes is extremely crucial for the survival and proper functioning of the cells. Organisms from all kingdoms of life employ specialized pore-forming proteins and toxins (PFPs and PFTs) that perforate cell membranes, and cause detrimental effects. PFPs/PFTs exert their damaging actions by forming oligomeric pores in the membrane lipid bilayer. PFPs/PFTs play important roles in diverse biological processes. Many pathogenic bacteria secrete PFTs for executing their virulence mechanisms. The immune system of the higher vertebrates employs PFPs to kill pathogen-infected cells and transformed cancer cells. The most obvious consequence of membrane pore-formation by the PFPs/PFTs is the killing of the target cells due to the disruption of the permeability barrier function of the plasma membranes. PFPs/PFTs can also activate diverse cellular processes that include activation of the stress-response pathways, induction of programmed cell death, and inflammation. Upon attack by the PFTs, host cells may also activate pathways to repair the injured membranes, restore cellular homeostasis, and trigger inflammatory immune responses. In this article, we present an overview of the diverse cellular responses that are triggered by the PFPs/PFTs, and their implications in the process of pathogen infection and immunity.

Demographic risk factors, affected anatomical sites and clinicopathological profile for oral squamous cell carcinoma in a north Indian population.

BACKGROUND: Oral cancer is a common form of cancer in India, particularly among men. About 95% are squamous cell carcinomas. Tobacco along with alcohol are regarded as the major risk factors. OBJECTIVES: (i) To determine associations of oral squamous cell carcinoma (OSCC) with respect to gender, age group, socioeconomic status and risk habits; (ii) To observe the distribution of affected oral anatomical sites and clinico-pathological profile in OSCC patients. MATERIALS AND METHODS: This is an unmatched case-control study during period January 2012 to December 2013. Total of 471 confirmed OSCC patients and 556 control subjects were enrolled. Data on socio-demography, risk habits with duration and medical history were recorded. RESULTS: There were significant associations between OSCC with middle age (41-50years; unadjusted OR=1.63, 95%CI=1.05-2.52, p=0.02) (51-60 years; unadjusted OR=1.79, 95%CI=1.15-2.79, p=0.009) and male subjects (unadjusted OR=2.49, 95%CI=1.89-3.27, p=0.0001). Cases with both habits of tobacco chewing and smoking were at a higher risk for OSCC than tobacco chewing alone (unadjusted OR=0.52, 95%CI=0.38-0.72, p=0.0001), duration of risk habits also emerged as a responsible factor for the development of carcinoma. The majority of patients were presented in well-differentiated carcinomas (39.9%). Prevalence of advance stages (TNM stage III, IV) was 23.4% and 18.3% respectively. The buccal mucosa was the most common (35.5%) affected oral site. CONCLUSIONS: In most Asian countries, especially India, there is an important need to initiate the national level public awareness programs to control and prevent oral cancer by screening for early diagnosis and support a tobacco free environment.

The correlation of routine tear function tests and conjunctival impression cytology in dry eye syndrome.

PURPOSE: To establish the strength of the association between routine tear function tests and conjunctival impression cytology (CIC) and to determine whether they simulate the morphological and cytological changes that occur on the ocular surface in dry eye. What are the sensitivity, specificity and positive predictive values of these tests when CIC is considered the gold standard? METHODS: The tear film profile included tear film break up time (TBUT), Schirmer's-1, Rose Bengal scores (RBS), and impression cytology. CIC samples were obtained from the inferior bulbar conjunctiva and stained with periodic acid-Schiff and counter stained with hematoxylin and eosin. RESULTS: The mean Schirmer's value was 11.66 ± 5.90 in patients and 17.17 ± 2.97 in controls (p < 0.001). The mean TBUT in participants was 8.88 ± 3.54 and 13.53 ± 2.12 in controls (p < 0.001). Patients had a mean goblet cell density (GCD) of 490 ± 213, while the value for controls was 1,462 ± 661 (p < 0.001). Abnormal CIC was observed in 46.7% cases of dry eye and in 32.8% of controls. The correlation coefficient (L) for Schirmer's was 0.2 and 0.24 for participants and controls, respectively, while TBUT values were 0.26 and 0.38, RBS were 0.5 and 0.5, and GCD was 0.8 and 0.6 in cases and controls, respectively. CONCLUSIONS: GCD, RBS, and TBUT were better predictors of morphological and cytological changes in the conjunctiva than Schirmer's in dry eye syndrome. The sensitivity of tear function tests in diagnosing dry eye was TBUT > Schirmer's > RBS, and the specificity was Schirmer's > TBUT > RBS in decreasing order when CIC was considered the gold standard.