Primary Tuberculosis of Tonsil Mimicking Carcinoma Tonsil

Tuberculosis is one of the major causes of ill health and death worldwide. Primary tuberculosis of the oral cavity and oropharynx is usually uncommon. Among tuberculosis of oral cavity and oropharynx, primary tuberculosis of tonsil in the absence of active pulmonary tuberculosis is a very rare clinical entity which presents difficulties in diagnosis because of similarity of presentation of carcinoma tonsil. Diagnosis mainly relies on the treating surgeon having a high index of suspicion. Although rare, tuberculosis should be kept in mind and considered in the differential diagnosis of any patient presenting with ulcer over tonsil.     

Clinical profile of scrub typhus in children and its association with hemophagocytic lymphohistiocytosis

Objective

To study the clinical profile of children with scrub typhus and its association with hemophagocytic lymphohistiocytosis.

Methods

Children presenting with unexplained fever and multi-systemic involvement between May to December 2011 were tested for scrub typhus using IgM ELISA kits. Occurrence of Hemophagocytic lymphohistiocytosis in IgM positive cases of scrub typhus was studied.

Results

Of the 35 children with unexplained fever and multi-systemic involvement, 15 children (9 boys) tested positive for scrub typhus. Thrombocytopenia, hypoalbuminemia and raised hepatic transaminases were observed in all children. Out of seven children evaluated for hemophagocytic lymphohistiocytosis. 3 met the criteria for hemophagocytosis. Two children (one with hemophagocytic lymphohistiocytosis) died.

Conclusions

Scrub typhus is a common cause of unexplained fever in children in northern India. Hemophagocytic lymphohistiocytosis can occasionally complicate scrub typhus in children.

     

CD28-independent,TRAF2-dependent Costimulation of Resting T Cells by 4-1BB Ligand

4-1BB ligand (4-1BBL) is a member of the tumor necrosis factor (TNF) family expressed on activated antigen-presenting cells. Its receptor, 4-1BB, is a member of the TNF receptor family expressed on activated CD4 and CD8 T cells. We have produced a soluble form of 4-1BBL using the baculovirus expression system. When coimmobilized on plastic with anti-CD3, soluble 4-1BBL induces interleukin (IL)-2 production by resting CD28⁺ or CD28⁻ T cells, indicating that 4-1BBL can function independently of other cell surface molecules, including CD28, in costimulation of resting T cell activation. At low concentrations of anti-CD3, 4-1BBL is inferior to anti-CD28 in T cell activation. However, when 4-1BB ligand is provided together with strong TCR signals, then 4-1BBL and anti-CD28 are equally potent in stimulation of IL-2 production by resting T cells. We find that TNF receptor–associated factor (TRAF)1 or TRAF2 associate with a glutathione S-transferase–4-1BB cytoplasmic domain fusion protein in vitro. In T cells, we find that association of TRAF1 and TRAF2 with 4-1BB requires 4-1BB cross-linking. In support of a functional role for TRAF2 in 4-1BB signaling, we find that resting T cells isolated from TRAF2-deficient mice or from mice expressing a dominant negative form of TRAF2 fail to augment IL-2 production in response to soluble 4-1BBL. Thus 4-1BB, via the TRAF2 molecule, can provide CD28-independent costimulatory signals to resting T cells.     

Magnetic resonance angiographic evaluation of circle of Willis: A morphologic study in a tertiary hospital set up

Background:

Anatomy of circle of Willis (CW) shows wide variation in different individuals, population groups, and has vital clinical significance in causation and presentation of clinical disease. This study evaluates the anatomical variations, incidence of various common anomalies of CW in south Indian tertiary hospital set up, using three-dimensional time-of-flight (3D-TOF) magnetic resonance angiography (MRA).

Materials and Methods:

A total of 300 patients referred for neuroimaging study over a period of 2-year were included in the analysis. In this prospective and retrospective study, 198 men and 102 women; mean age, 55 years) underwent 3D-TOF MR angiograms of the CW using a 1.5-tesla MR scanner. Images were reviewed for anatomical configuration of the CW using maximum intensity projection (MIP) and 3D volume rendered images.

Results:

On analysis, a complete CW was seen in 50 (16.6%) of 300 subjects. An incomplete anterior and posterior CW was found in 66 (22%) The remaining 184 (61.3%) subjects had partially complete CW configuration. The most common type of CW in a single subject was anterior variant type A and posterior type variant E.

Conclusion:

We observed wide variation in CW configuration in our patients. The prevalence of complete configuration of the circle is 16.6%; slightly higher in females and younger subjects. Complete anterior circle was present in 77.3%. Most common anterior variant is type A (normal anterior configuration) with a prevalence of 66%. The most common posterior circle variant is type E (hypoplasia or absence of both PcomA) with 32.6%. Overall, CW variants are slightly more common among the women in comparison to men. Incidence of associated anomalies like aneurysm or arteriovenous malformation (AVM) was comparable to that described in literature.     

Effectiveness and future implications of COVID-19-related risk stratification for managing retinopathy of prematurity: The Indian twin cities retinopathy of prematurity study report number 10

Purpose:To evaluate the effectiveness and future implications of COVID-related risk stratification for managing retinopathy of prematurity (ROP).Methods:A prospective study was conducted at a tertiary eye care center from the beginning of the lockdown in India from 23 March 2020 till the end of the first phase of lockdown on 29 May 2020. We evaluated 200 prematurely born infants (< 34 weeks of gestational age) using the new safety guideline protocols for low-risk babies developed in conjunction with the Indian ROP Society for care during the COVID-19 pandemic. Low risk included babies born at more than 30 weeks of gestational age, post menstrual age 34 weeks or above at presentation, more than 1000 grams of birth weight, and stable systemically with good weight gain.Results:New guidelines were implemented in 106 (53%) infants who were low risk while 94 (47%) infants with high risk were followed up as per the old guidelines. Out of the 106 infants (212 eyes) managed by the new guidelines, good outcome (group 1) was seen in 102 (96.2%) infants. Twenty-seven of the 102 infants had some form of ROP and 5 of these infants needed treatment. None of the low-risk babies with no detachment at presentation managed by new guidelines required surgery later (group 2). Two (1.9%) infants came with retinal detachment at presentation and underwent successful surgery (group 3) and two infants (1.9%) were lost to follow up.Conclusion:New risk stratification during the COVID-19 pandemic was an efficient and safe strategy in managing low-risk ROP babies.     

Bayesian Molecular Dating Analyses Combined with Mutational Profiling Suggest an Independent Origin and Evolution of SARS-CoV-2 Omicron BA.1 and BA.2 Sub-Lineages

The ongoing evolution of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has resulted in the recent emergence of a highly divergent variant of concern (VOC) defined as Omicron or B.1.1.529. This VOC is of particular concern because it has the potential to evade most therapeutic antibodies and has undergone a sustained genetic evolution, resulting in the emergence of five distinct sub-lineages. However, the evolutionary dynamics of the initially identified Omicron BA.1 and BA.2 sub-lineages remain poorly understood. Herein, we combined Bayesian phylogenetic analysis, mutational profiling, and selection pressure analysis to track the virus’s genetic changes that drive the early evolutionary dynamics of the Omicron. Based on the Omicron dataset chosen for the improved temporal signals and sampled globally between November 2021 and January 2022, the most recent common ancestor (tMRCA) and substitution rates for BA.1 were estimated to be that of 18 September 2021 (95% highest posterior density (HPD), 4 August–22 October 2021) and 1.435 × 10⁻³ (95% HPD  =  1.021 × 10⁻³ − 1.869 × 10⁻³) substitution/site/year, respectively, whereas 3 November 2021 (95% highest posterior density (HPD) 26 September–28 November 2021) and 1.074 × 10⁻³ (95% HPD  =  6.444 × 10⁻⁴ − 1.586 × 10⁻³) substitution/site/year were estimated for the BA.2 sub-lineage. The findings of this study suggest that the Omicron BA.1 and BA.2 sub-lineages originated independently and evolved over time. Furthermore, we identified multiple sites in the spike protein undergoing continued diversifying selection that may alter the neutralization profile of BA.1. This study sheds light on the ongoing global genomic surveillance and Bayesian molecular dating analyses to better understand the evolutionary dynamics of the virus and, as a result, mitigate the impact of emerging variants on public health.