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The treatment of retinoblastoma (Rb) has improved significantly in recent times. Worldwide, there is an increasing trend to use conservative treatment modalities that aim to preserve the globe as well as vision with minimum morbidity. Recently, the use of targeted delivery of chemotherapy to the eye in the form of selective intra-arterial and intravitreal chemotherapy has shown promising results. Radiotherapy is beneficial in selected cases, either in the form of plaque brachytherapy or as external beam radiotherapy. Orbital disease carries a poor prognosis for survival. However, a multimodal treatment protocol has improved survival in children with extraocular disease. Nevertheless, challenges remain, especially for the developing world. This review aims to highlight recent advances in the management of Rb that have contributed towards improving treatment outcomes and also discuss the challenges ahead, with special reference to the Indian scenario.

ObjectiveTo study the clinical presentation and survival among Indian children with retinoblastoma (RB) and to determine factors predictive of poor outcome.MethodsA retrospective review of children newly diagnosed with RB at a tertiary referral centre was undertaken. Demographic and clinical characteristics and treatment outcomes were studied.ResultsA total of 600 patients (unilateral 67.6%, bilateral 32.4%) was studied. 61% was boys. The median age at presentation was 29 months (18 months vs 36 months in bilateral and unilateral cases, respectively, p<0.001). leukocoria was most common (83%), followed by proptosis (17%). Tumours were intraocular in 72.3% and extraocular in 27.7% cases. In the intraocular group, 78% were advanced Group D or E disease. Metastasis to the central nervous system was noted in 15.7% of extraocular cases. A statistically significant difference was seen between intraocular and extraocular groups in the median age (24 months vs 37.5 months, p<0.001) and median lag period (2.5 months vs 7 months, p<0.001). The Kaplan-Meier survival probability was 83%, 73% and 65% at 1 year, 2 years and 5 years, respectively. On univariate analysis, age >2 years (p=0.002), lag period >6 months (p=0.004) and extraocular stage (p<0.001) were associated with poor outcome. On multivariate analysis, extraocular invasion was predictive of low survival (HR 5.04, p<0.001).ConclusionsDelayed presentation is a matter of concern. Improving awareness about the early signs and creating facilities for diagnosing and treating RB at the primary and secondary levels of healthcare are required to reduce mortality and morbidity, and lead to improved outcomes that are comparable with the developed nations.

Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis (VL) and is responsible for significant mortality and morbidity. Increasing resistance towards antimonial drugs poses a great challenge in chemotherapy of VL. Paromomycin is an aminoglycosidic antibiotic and is one of the drugs currently being used in the chemotherapy of cutaneous and visceral leishmaniasis. To understand the mode of action of this antibiotic at the molecular level, we have investigated the global proteome differences between the wild type AG83 strain and a paromomycin resistant (PRr) strain of L. donovani. Stable isotope labeling of amino acids in cell culture (SILAC) followed by quantitative mass spectrometry of the wild type AG83 strain and the paromomycin resistant (PRr) strain identified a total of 226 proteins at ≥ 95% confidence. Data analysis revealed upregulation of 29 proteins and down-regulation of 21 proteins in the PRr strain. Comparative proteomic analysis of the wild type and the paromomycin resistant strains showed upregulation of the ribosomal proteins in the resistant strain indicating role in translation. Elevated levels of glycolytic enzymes and stress proteins were also observed in the PRr strain. Most importantly, we observed upregulation of proteins that may have a role in intracellular survival and vesicular trafficking in the PRr strain. Furthermore, ultra-structural analysis by electron microscopy demonstrated increased number of vesicular vacuoles in PRr strain when compared to the wild-type strain. Drug affinity pull-down assay followed by mass spectrometery identified proteins in L. donovani wild type strain that were specifically and covalently bound to paromomycin. These results provide the first comprehensive insight into the mode of action and underlying mechanism of resistance to paromomycin in Leishmania donovani.

Retinoblastoma is the most common primary intraocular malignancy of childhood. A potentially curable cancer, its treatment has improved significantly over the last few decades. The purpose of this article is to review the literature on various conservative treatment modalities available for the treatment of retinoblastoma and their effectiveness, when used alone or in combination. Pubmed, Medline, Embase, and the Cochrane library were searched through 2012 for published peer reviewed data on conservative treatment modalities for retinoblastoma. Various studies show that while enucleation remains the standard of care for advanced intraocular tumors, conservative modalities that can result in globe salvage and preservation of useful vision are being increasingly employed. Such modalities include systemic chemotherapy, focal consolidation with transpupillary thermotherapy, laser photocoagulation and cryotherapy, plaque brachytherapy, and delivery of local chemotherapy using subconjunctival, sub-tenon, or intra-arterial routes. When used alone or in combination, these treatment modalities can help in avoidance of external beam radiotherapy or enucleation, thus reducing the potential for long-term side effects, while salvaging useful vision. Radioactive plaque brachytherapy has an established role in selected patients with intraocular retinoblastoma. Local injections of chemotherapeutic agents via the sub-tenon or sub-conjunctival route have been used with varying degrees of success, usually as an adjunct to systemic chemotherapy. Intra-arterial ophthalmic artery delivery of melphalan has shown promising results. It is important to recognize that today, several treatment options are available that can obviate the need for enucleation, and cure the cancer with preservation of functional vision. A thorough knowledge and understanding of these conservative treatment modalities is essential for appropriate management.

Most COVID-19 vaccine trials have focused on recipient protection, not protection of their contacts, a critical need. As a subunit intranasal COVID-19 vaccine reduced nasopharyngeal virus more than did an intramuscular (IM) vaccine, we hypothesized that this vaccine might reduce onward transmission to others. We vaccinated hamsters with either the IM-administrated licensed mRNA vaccine twice or one dose of mRNA IM followed by adjuvanted subunit intranasal vaccine. 24 hours after SARS-CoV-2 challenge, these animals were housed with naïve recipients in a contactless chamber that allows airborne transmission. Onward airborne transmission was profoundly blocked: the donor and recipients of the intranasal vaccine-boosted group had lower oral and lung viral loads (VL), which correlated with mucosal ACE2 inhibition activity. Notably, in this head-to-head comparison of COVID-19 booster vaccines on SARS-CoV-2 onward transmission, we found that statistically significant viral reduction in the lung tissues and oral swabs was observed only in the intranasal S1 nanoparticle vaccine-boosted group, but not in the systemic mRNA vaccine-boosted group, suggesting the superior protection of this intranasal vaccine, which could act as an attractive vaccine booster candidate to complement the current licensed systemic vaccines. Overall, our study strongly supports the use of the intranasal vaccine as a boost to protect not only the vaccinated person, but also people exposed to the vaccinated person, a key public health goal.

Anterior segment tumors pose challenges in treatment due to their location and potential for globe loss. Plaque brachytherapy allows globe salvage, but placing plaques over the cornea and limbus may lead to epithelial defects and ulcers. We report a novel technique using a bandage contact lens as a buffer between the plaque and cornea in a 48-year-old woman with iridociliary melanoma. The lens thickness (0.07 mm) was included in radiation dose planning. The patient had no corneal complications and showed tumor regression at seven months. Two additional patients treated similarly showed stable tumors and no adverse effects at six months. This method may offer a safer alternative to amniotic membrane grafts for anterior segment brachytherapy, reducing corneal toxicity without compromising tumor control.

Macrophages express a wide array of invariant receptors that facilitate host defense and mediate pathogenesis during pathogen invasion. We report on a novel population of CD11bhighCD14+F4/80+ macrophages that express TCRβ. This population expands dramatically during a Plasmodium berghei ANKA infection and sequesters in the brain during experimental cerebral malaria. Importantly, measurement of TCRβ transcript and protein levels in macrophages in wildtype versus nude and Rag1 knockout mice establishes that the observed expression is not a consequence of passive receptor expression due to phagocytosis or trogocytosis of peripheral T cells or nonspecific antibody staining to an Fc receptor or cross reactive epitope. We also demonstrate that TCRβ on brain sequestered macrophages undergoes productive gene rearrangements and shows preferential Vβ usage. Remarkably, there is a significant correlation in the proportion of macrophages that express TCRβ and peripheral parasitemia. In addition, presence of TCRβ on the macrophage also correlates with a significant increase (1.9 fold) in the phagocytosis of parasitized erythrocytes. By transcriptional profiling, we identify a novel set of genes and pathways that associate with TCRβ expression by the macrophage. Expansion of TCRβ-expressing macrophages points towards a convergence of the innate and adaptive immune responses where both arms of the immune system cooperate to modulate the host response to malaria and possibly other infections.

Deoxyhypusine hydroxylase (DOHH) catalyzes the final step in the post-translational synthesis of an unusual amino acid hypusine (N(€)-(4-amino-2-hydroxybutyl) lysine), which is present on only one cellular protein, eukaryotic initiation factor 5A (eIF5A). We present here the molecular and structural basis of the function of DOHH from the protozoan parasite, Leishmania donovani, which causes visceral leishmaniasis. The L. donovani DOHH gene is 981 bp and encodes a putative polypeptide of 326 amino acids. DOHH is a HEAT-repeat protein with eight tandem repeats of α-helical pairs. Four conserved histidine-glutamate sequences have been identified that may act as metal coordination sites. A ~42 kDa recombinant protein with a His-tag was obtained by heterologous expression of DOHH in Escherichia coli. Purified recombinant DOHH effectively catalyzed the hydroxylation of the intermediate, eIF5A-deoxyhypusine (eIF5A-Dhp), in vitro. L. donovani DOHH (LdDOHH) showed ~40.6% sequence identity with its human homolog. The alignment of L. donovani DOHH with the human homolog shows that there are two significant insertions in the former, corresponding to the alignment positions 159-162 (four amino acid residues) and 174-183 (ten amino acid residues) which are present in the variable loop connecting the N- and C-terminal halves of the protein, the latter being present near the substrate binding site. Deletion of the ten-amino-acid-long insertion decreased LdDOHH activity to 14% of the wild type recombinant LdDOHH. Metal chelators like ciclopirox olamine (CPX) and mimosine significantly inhibited the growth of L. donovani and DOHH activity in vitro. These inhibitors were more effective against the parasite enzyme than the human enzyme. This report, for the first time, confirms the presence of a complete hypusine pathway in a kinetoplastid unlike eubacteria and archaea. The structural differences between the L. donovani DOHH and the human homolog may be exploited for structure based design of selective inhibitors against the parasite.

Purpose: A pilot randomized control trial to compare the efficacy and side effects of intralesional and oral propranolol in periorbital and eyelid capillary hemangiomas. Methods: Twenty patients were prospectively randomized to two groups of ten each. Group 1 was initiated on oral propranolol 1 mg/kg/day titrated to final dose of 3 mg/kg/day over 1 week which was continued for 6 months and then tapered over 1 week; Group 2 received 3 doses of direct intralesional propranolol hydrochloride 1 mg/ml; 0.2 ml/cm 4-6 weeks apart. Hemangioma area and corneal astigmatism were measured. Results: Within each group at 6 months there was a significant reduction in area (group 1: 83.48 ± 11.67%,P= 0.0019; group 2: 67.78 ± 21.71%,P= 0.0019) and improvement in astigmatism (pre, post: group 1: 2.98D @ 179.8°, 1.13D @ 179.8°,P= 0.0045; group 2: 1.62D @ 90.16°, 0.75D @ 179.9°,P= 0.0001). There was no difference in area reduction (P = 0.056), change in appearance (P = 0.085), ptosis (P = 0.23) and side effects (lethargy, poor feeding;P= 0.171) between the two groups. Conclusion: Efficacy and side effects with intralesional propranolol are comparable to oral propranolol for periorbital and eyelid lesions.