Aurora Kinase A Is Overexpressed in Human Retinoblastoma and Correlates with Histopathologic High-Risk Factors: Implications for Targeted Therapy

Retinoblastoma (RB) is an intraocular malignancy initiated by loss of RB1 function and/or dysregulation of MYCN oncogene. RB is primarily treated with chemotherapy; however, systemic toxicity and long-term adverse effects remain a significant challenge necessitating the identification of specific molecular targets. Aurora kinase A (AURKA), a critical cell cycle regulator, contributes to cancer pathogenesis, especially in RB1-deficient and MYCN-dysregulated tumors. The current immunohistochemistry study in patient specimens (n = 67) indicated that AURKA is overexpressed in RB, and this elevated expression correlates with one or more histopathologic high-risk factors, such as tumor involvement of the optic nerve, choroid, sclera, and/or anterior segment. More specifically, AURKA is ubiquitously expressed in most advanced-stage RB tumors that show a suboptimal response to chemotherapy. shRNA-mediated depletion/pharmacologic inhibition studies in cell lines, patient-derived cells, in vivo xenografts, and enucleated patient specimens confirmed that RB cells are highly sensitive to a lack of functional AURKA. In addition, AURKA and N-myc proto-oncogene protein (MYCN) associate with each other to regulate their levels in RB cells. Overall, these results demonstrate a previously unknown up-regulation of AURKA in RB, facilitated by its crosstalk with MYCN. The elevated levels of this kinase may indicate unfavorable prognosis in tumors refractory to chemotherapy. This study provides a rationale and confirms that therapeutic targeting of elevated AURKA in RB could be a potential treatment approach.

Alterations of adipokines, pancreatic hormones and incretins in acute and convalescent COVID-19 children

BACKGROUND

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), accountable for Coronavirus disease 2019 (COVID-19), may cause hyperglycemia and additional systemic complexity in metabolic parameters. It is unsure even if the virus itself causes type 1 or type 2 diabetes mellitus (T1DM or T2DM). Furthermore, it is still unclear whether even recuperating COVID-19 individuals have an increased chance to develop new-onset diabetes.

METHODS

We wanted to determine the impact of COVID-19 on the levels of adipokines, pancreatic hormones, incretins and cytokines in acute COVID-19, convalescent COVID-19 and control children through an observational study. We performed a multiplex immune assay analysis and compared the plasma levels of adipocytokines, pancreatic hormones, incretins and cytokines of children presenting with acute COVID-19 infection and convalescent COVID-19.

RESULTS

Acute COVID-19 children had significantly elevated levels of adipsin, leptin, insulin, C-peptide, glucagon and ghrelin in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had elevated levels of adipsin, leptin, insulin, C-peptide, glucagon, ghrelin and Glucagon-like peptide-1 (GLP-1) in comparison to control children. On the other hand, acute COVID-19 children had significantly decreased levels of adiponectin and Gastric Inhibitory Peptide (GIP) in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had decreased levels of adiponectin and GIP in comparison to control children. Acute COVID-19 children had significantly elevated levels of cytokines, (Interferon (IFN)) IFNγ, Interleukins (IL)-2, TNFα, IL-1α, IL-1β, IFNα, IFNβ, IL-6, IL-12, IL-17A and Granulocyte-Colony Stimulating Factors (G-CSF) in comparison to convalescent COVID-19 and controls. Convalescent COVID-19 children had elevated levels of IFNγ, IL-2, TNFα, IL-1α, IL-1β, IFNα, IFNβ, IL-6, IL-12, IL-17A and G-CSF in comparison to control children. Additionally, Principal component Analysis (PCA) analysis distinguishes acute COVID-19 from convalescent COVID-19 and controls. The adipokines exhibited a significant correlation with the levels of pro-inflammatory cytokines.

CONCLUSION

Children with acute COVID-19 show significant glycometabolic impairment and exaggerated cytokine responses, which is different from convalescent COVID-19 infection and controls.

Past, present, and prospects in microsporidial keratoconjunctivitis- A review

Ocular microsporidiosis comprises two entirely different spectra of disease as keratoconjunctivitis and stromal keratitis. Microsporidial keratoconjunctivitis (MKC) has been increasingly reported in the past two decades, probably due to raised awareness, simpler diagnostic procedures, and a better understanding of the clinical presentation. It is characterized by the presence of raised, coarse, punctate, multifocal, round to oval, greyish-white corneal epithelial lesions which usually evolve into nummular scars before resolution. Conjunctivitis seen is non-purulent and of mild-moderate intensity, with mixed papillary-follicular reaction. The mode of transmission and pathogenesis is poorly understood. Despite lack of inflammatory response, uncommon associations reported were- endotheliitis, corneal edema, limbitis, uveitis, and sub-epithelial infiltrates. There has been no consensus on the management of MKC. It varies from the use of multiple antimicrobial agents to simple lubricants. The majority of the disease goes underdiagnosed or misdiagnosed and treated as adenoviral keratoconjunctivitis, with topical steroids or anti-virals empirically. Changing trends have been noticed in the pattern of infection, possibly with increasing evidence of Vittaforma corneae as causative organisms, previously reported to cause stromal keratitis. An elaborate review of the past and present literature on MKC is provided in this review article, along with gaps in knowledge, and future directions of research.

Computational modeling of drug dissolution in the human stomach: Effects of posture and gastroparesis on drug bioavailability

The oral route is the most common choice for drug administration because of several advantages, such as convenience, low cost, and high patient compliance, and the demand and investment in research and development for oral drugs continue to grow. The rate of dissolution and gastric emptying of the dissolved active pharmaceutical ingredient (API) into the duodenum is modulated by gastric motility, physical properties of the pill, and the contents of the stomach, but current in vitro procedures for assessing dissolution of oral drugs are limited in their ability to recapitulate this process. This is particularly relevant for disease conditions, such as gastroparesis, that alter the anatomy and/or physiology of the stomach. In silico models of gastric biomechanics offer the potential for overcoming these limitations of existing methods. In the current study, we employ a biomimetic in silico simulator based on the realistic anatomy and morphology of the stomach (referred to as "StomachSim") to investigate and quantify the effect of body posture and stomach motility on drug bioavailability. The simulations show that changes in posture can potentially have a significant (up to 83%) effect on the emptying rate of the API into the duodenum. Similarly, a reduction in antral contractility associated with gastroparesis can also be found to significantly reduce the dissolution of the pill as well as emptying of the API into the duodenum. The simulations show that for an equivalent motility index, the reduction in gastric emptying due to neuropathic gastroparesis is larger by a factor of about five compared to myopathic gastroparesis.

Intra-orbital fat necrosis following transcaruncular orbitotomy mimicking a surgical site infection: A case report

Fat necrosis is a benign non-suppurative inflammation of adipose tissue most commonly occurring in breast, subcutaneous tissue or intraabdominal fat post trauma, surgery, radiation. Transcaruncularorbitotomy provides a safe, rapid, and cosmetically pleasing approach to the medial wall and orbital apex. Intraorbital fat necrosis as its complication has not been documented in literature. The authors report the case of an elderly lady who presented with localized pain, swelling following a transcaruncular orbitotomy for excision biopsy of an orbital vascular mass. The etiology, clinical presentation, intraoperative finding, imaging, and possible mechanisms contributing to the pathogenesis of postsurgical orbital fat necrosis has been suggested.

Microsporidial Endotheliitis Mimicking Graft Rejection After Deep Anterior Lamellar Keratoplasty

PURPOSE

The purpose of this study was to report a case of microsporidial endotheliitis masquerading as graft rejection after deep anterior lamellar keratoplasty (DALK).

METHODS

A 36-year-old man visited the clinic with complaints of blurred vision, redness, pain, watering, and whitish appearance of the black portion of his left eye. On evaluation, there was diffuse stromal edema with epithelial defect and hypopyon. Microbial keratitis resolved with macular grade scar. He underwent DALK. After 3 years, he presented with complaints of sudden diminution of vision in the same eye for 10 days. His unaided visual acuity was counting finger 1 meter. The clinical findings were circumcorneal congestion, diffuse graft edema, Descemet membrane folds, and diffuse keratic precipitates. A presumptive diagnosis of left eye graft rejection was made. Topical steroids were administered. There was significant improvement within a week. However, at 1 month, there was an increase in graft edema after the steroids were tapered. At this point, a diagnosis of endotheliitis of viral origin was made. He was then administered oral antivirals and steroids. There were 2 such waxing and waning episodes of graft edema before the graft failed. Patient underwent penetrating keratoplasty with cataract extraction with intraocular lens implantation.

RESULTS

The previous donor and host Descemet endothelium complex was sent for histopathology and polymerase chain reaction. Both histology and polymerase chain reaction were positive for microsporidia.

CONCLUSIONS

Microsporidial endotheliitis may present as graft rejection. There should be a suspicion of microsporidial infection in cases of features mimicking as endothelial rejection after DALK.

Evidence-based funding of new imaging applications and technologies by Medicare in Australia: How it happens and how it can be improved

BACKGROUND

The Medical Services Advisory Committee (MSAC) is responsible for the assessment of medical imaging tests proposed for public funding. A number of factors related to the clinical or cost effectiveness of an imaging service may impact on the funding decision.

OBJECTIVE

To determine what evidentiary and economic factors impact most on MSAC recommendations for the funding of imaging tests.

METHODS

Information was extracted on health technology assessments (HTAs) of medical imaging tests published on the MSAC website, with a funding decision between 2006 to July 2021. Imaging tests with diagnostic, staging or screening indications were eligible. Data were extracted in test-indication pairs and included data on evidence quality, quantity, consistency of findings, cost-effectiveness and financial impact. Multivariate logistic regression analysis was performed with adjustments for clustered data.

RESULTS

Overall, 42 imaging test applications to MSAC were included, representing 91 clinical indications. Most were diagnostic tests. The most common evidentiary concerns reported by MSAC were limited evidence (36%), low quality evidence (26%), and applicability of the data (22%). The reference standard for diagnostic accuracy was imperfect or not appropriate in 25% of the indications. In regression analyses, uncertainty about cost-effectiveness of an imaging service predicted most negative funding decisions.

CONCLUSIONS

The single biggest contributor to a negative funding decision by MSAC was uncertainty about the cost-effectiveness of the imaging service. This was likely driven by uncertainty regarding the impact on patient health. HTAs that are able to demonstrate the clinical utility of a new imaging service are more likely to publicly funded.

Post-cricoid and Upper Oesophagus Cancers Treated with Organ Preservation Using Intensity-modulated Image-guided Radiotherapy: a Phase II Prospective Study of Outcomes, Toxicity and Quality of Life

AIMS

To prospectively examine the outcomes, toxicity and quality of life (QoL) of patients with post-cricoid and upper oesophagus (PCUE) cancers treated with an organ-preservation approach of (chemo)-radiotherapy using intensity-modulated image-guided radiotherapy (IM-IGRT).

MATERIALS AND METHODS

This phase II prospective study was conducted at a tertiary cancer centre from February 2017 to January 2020. Forty patients with squamous cell carcinoma of PCUE of stage T1-3, N0-2, M0 were accrued. Gross exolaryngeal extension/dysfunctional larynx were major exclusion criteria. Patients received 63-66 Gy in once-daily fractions using volumetric modulated arc therapy with daily IGRT. Outcome measures included disease-related outcomes, patterns of failure, Radiation Therapy Oncology Group toxicities, feeding tube dependency and QoL.

RESULTS

The median follow-up was 22 months. Twenty-six (87.5%) patients had locoregionally advanced disease and 34 (85%) patients received (chemo)-radiotherapy. A complete response was observed in 26 (65%) patients. The 2-year locoregional control, event-free survival and cause-specific survival were 59.6%, 40.2% and 44.8%, respectively. The volume of primary tumour (GTVPvol) exceeding 28 cm³ had inferior overall survival (P = 0.005) on univariate analysis. Multivariable analysis showed GTVPvol and positron emission tomography-computed tomography maximum standardised uptake value to be independently predictive for event-free and overall survival. A feeding tube requirement at presentation was seen in 11 (27.5%) patients, whereas long-term feeding tube dependency at 6 months was seen in 10 (37%) patients. For QoL, a statistical improvement in pain, appetite loss and swallowing was observed over time.

CONCLUSION

Although the outcomes of PCUE cancers remain dismal, the use of state of the art diagnostic modalities, careful case selection and modern radiotherapy techniques improved outcomes as compared with before in this exclusive analysis of PCUE cancers.

The Oncogene MYCN Modulates Glycolytic and Invasive Genes to Enhance Cell Viability and Migration in Human Retinoblastoma

Retinoblastoma is usually initiated by biallelic RB1 gene inactivation. In addition, MYCN copy number alterations also contribute to RB pathogenesis. However, MYCN expression, its role in disease progression and correlation with RB histological risk factors are not well understood. We studied the expression of MYCN in enucleated RB patient specimens by immunohistochemistry. MYCN is overexpressed in RB compared to control retina. Our microarray gene expression analysis followed by qRT-PCR validation revealed that genes involved in glucose metabolism and migration are significantly downregulated in MYCN knockdown cells. Further, targeting MYCN in RB cells using small molecule compounds or shRNAs led to decreased cell survival and migration, increased apoptosis and cell cycle arrest, suggesting that MYCN inhibition can be a potential therapeutic strategy. We also noted that MYCN inhibition results in reduction in glucose uptake, lactate production, ROS levels and gelatinolytic activity of active-MMP9, explaining a possible mechanism of MYCN in RB. Taking clues from our findings, we tested a combination treatment of RB cells with carboplatin and MYCN inhibitors to find enhanced therapeutic efficacy compared to single drug treatment. Thus, MYCN inhibition can be a potential therapeutic strategy in combination with existing chemotherapy drugs to restrict tumor cell growth in RB.

Changing patterns of posterior segment trauma during the COVID-19 pandemic: A regional analysis from the Bodhya Eye Consortium

Purpose

To assess changes in the presentation patterns of posterior segment trauma during the COVID-19 pandemic from six tertiary eye care institutes of North and Central India.

Methods

A multicenter, hospital-based, retrospective comparative analysis of patients presenting with posterior segment trauma was done during the COVID-19 (Group A) (March 25, 2020 - September 30, 2020) period and the pre-COVID-19 (Group B) (March 25, 2019 - September 30, 2019) period.

Results

A total of 405 patients were diagnosed with posterior segment trauma (Group A: 206, Group B: 199). The time interval between onset of trauma and presentation was higher in Group A (16.59 ± 29.87 days) as compared to Group B (9.41 ± 19.19 days) (P = 0.004). A majority of patients in Group A had a history of prior consultation before presentation (P = 0.049). In Group A, 120 (58.2%) patients sustained ocular trauma at home as compared to 80 (40.2%) patients in Group B (P < 0.0001). Patients presenting with light perception were significantly more in Group A (43.7%) as compared to Group B (30.2%) (P = 0.004). In Group B, 37.6% patients had presenting visual acuity of counting finger or better as compared to 27.6% patients in Group A (P = 0.07). Patients in Group A had a significantly higher proportion of post-traumatic endophthalmitis with delayed presentation (P = 0.011) and retinal detachment (P = 0.041). Patients undergoing surgery for foreign-body removal were significantly fewer in Group A (P = 0.05).

Conclusion

Although the number of patients presenting with posterior segment trauma was comparable in Groups A and B, a greater number of patients sustained home injuries during the COVID-19 pandemic. A majority of these patients had delayed presentation with poor presenting visual acuity and a higher tendency of retinal detachment.

Pythium keratitis: Clinical profile, laboratory diagnosis, treatment, and histopathology features post-treatment at a tertiary eye care center in Eastern India

Purpose:

The aim of this work was to study demography, clinical profile, laboratory diagnosis, and management of Pythium keratitis at a tertiary eye care center in Eastern India.

Methods:

Eighteen patients with culture-positive Pythium keratitis managed at our center between January 2016 and December 2018 were included in this retrospective study. Clinical features, laboratory investigations, treatment, and outcomes were analysed.

Results:

Pythium keratitis commonly affects middle-aged males with low socioeconomic profile and history of trauma. Samples stained with Gomori methenamine silver showed 93.8% positivity and Iodine-potassium iodide-sulfuric acid showed 100% positivity. Periodic acid-Schiff's showed negative staining in 62.5% and weak in 37.5%. Kirby-Bauer disc diffusion method showed zone of inhibition as 30.25 ± 4.61 mm for Linezolid and 23.56 ± 6.86 mm for Azithromycin. Medical management included topical/oral linezolid and azithromycin. Therapeutic penetrating keratoplasty (TPK) was done in 15 eyes (83.3%), repeat TPK in 4 eyes, and evisceration in 3 eyes (16.7%). One patient required only medical treatment. Globe salvation was obtained in 15 (83.3%) eyes, and good visual outcome in 7 eyes (38. 9%). There was graft failure in six eyes (40%) and two (11.1%) eyes went into phthisis. Patients were divided into early and late presenters. Late presenters had more complications and worse final visual outcome.

Conclusion:

Pythium keratitis can be differentiated from fungal keratitis by its characteristic appearance on slit-lamp examination, smear, culture, and histopathology. Early presentation, detection, and treatment with antibacterial drugs like linezolid and azithromycin results in a better prognosis. Early full-thickness corneal transplant should be considered for Pythium keratitis not responding to treatment.

Acid and heat fastness in microsporidia: How acid fast are acid fast microsporidium?

Microsporidia are obligate spore-forming microorganisms with strong resemblance to fungi and can affect almost every organ system in immunocompetent or immunocompromised individuals. Mixed infections are also reported in immunocompromised hosts. Microsporidial spores show marked morphological variations and the small and slender forms can resemble bacilli. Modified Zeihl Neelsen (ZN) stain, cold method demonstrates them as bright red in color, leaving several spores blue or incompletely stained; thus, they are reported as weakly or variably acid fast. Variability in staining results with ZN stain and considering the fact that Mycobacterium tuberculosis, the commoner bug in developing countries is identified by its resistance to stronger acids on ZN staining, authors wished to demonstrate acid and heat fastness in microsporidium using corneal tissue specimens. Microsporidial spores stained bright red in color with conventional ZN stain, demonstrated strong acid fastness, and interestingly the staining results improved on heating. Thus, the authors conclude that they are strongly acid and heat fast and care must be warranted so that they are not misdiagnosed as Mycobacterium or other acid-fast organisms. Careful observation of morphology, battery of special stains, and molecular diagnostics should be advocated for diagnostic confirmation. To the best of the authors' knowledge, this is the first explicit report on acid and heat fastness on microsporidial spores.

Computational insights of phytochemical-driven disruption of RNA-dependent RNA polymerase-mediated replication of coronavirus: a strategic treatment plan against coronavirus disease 2019

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised global health concerns. RNA-dependent RNA polymerase (RdRp) is the prime component of viral replication/proliferation machinery and is considered to be a potential drug target against SARS-CoV-2. The present study investigated the anti-RdRp activity of phytochemicals against SARS-CoV-2 infection. Virtual ligand screening was carried out to determine the potent compounds against RdRp. Molecular docking and an MD Simulation study were employed to evaluate the spatial affinity of selected phytochemicals for the active sites of RdRp. Structural stability of target compounds was determined using root mean square deviation computational analysis and drug-like abilities were investigated using ADMET. Bond distances between ligand and receptor were marked to predict the strength of interaction. Aloe, azadirachtin, columbin, cirsilineol, nimbiol, nimbocinol and sage exhibited the highest binding affinities and interacted with active sites of RdRp, surpassing the ability of chloroquine, lamivudine, favipiravir and remdesivir to target the same. All the natural metabolites exhibited stable conformation during MD Simulation of 101 ns at 310 K. Kinetic, potential and electrostatic energy were observed to be least in the case of natural metabolites in comparison with synthetic analogues. Deviations and fluctuations were observed to be structurally least in target phytochemicals. Physiochemical and biological properties of these compounds further validated their drug-like properties. Non-bonded distance was found to be short enough to form hydrogen bonding or hydrophobic interactions, which revealed that these target compounds can strongly bind with RdRp. The study found potential phytochemicals to disrupt the replication domain of SARS-CoV-2 by hindering RdRp. We therefore anticipate that the current findings could be considered as valuable for the development of an efficient preventive/therapeutic expedient against COVID-19.

Use of impregnated catheters to decrease colonization rates in neonates - A randomized controlled pilot trial

OBJECTIVE

Nosocomial infections increase mortality and morbidity in preterm infants. Central venous line colonization is a major risk factor for the development of such infections. In adults and children, antibiotic and antimycotic impregnated catheters have been demonstrated to reduce colonization. However, recently published data showed no significant difference in bloodstream infection in neonates when an impregnated catheter was used. We investigated the effect of impregnation of percutaneously inserted micro-catheters (PICC) on colonization in preterm and sick term infants in our unit.

METHODS

Neonates were randomly assigned to receive either a standard (S-PICC; n = 34) or antibiotic and antimycotic impregnated (IP-PICC; n = 37) PICC. Catheters were placed and removed according to a standard procedure and subsequently examined by roll-out culture. The primary outcome was the rate of colonization defined as >15 colony-forming-units/ml. Additional outcomes were catheter associated or systemic infections.

RESULTS

The rate of colonization was lower in neonates who received an IP-PICC as compared to S-PICC (5.6% vs. 12.1% respectively; p = 0.42). However, the difference was not significant. In IP-PICC vs S-PICC, catheter related local infection (CRI) although lower was not statistically significant (2.9% vs. 6.1%; p = 0.60). We observed no difference in catheter related systemic infection (CR-SI) (0% vs. 3.1%, p = 0.48). The neonates whose catheters were colonized were predominantly of a lower gestational age (median 254/7, p = 0.05) and males (100%, p = 0.01). In addition, the median colony count in the colonized IP-PICC catheters was lower as compared to S- PICC group (53 vs 250, p = 0.06).

CONCLUSIONS

The use of antibiotic and antimycotic impregnated PICC-lines in neonates tended to decrease colonization rates in neonates in our centers but this difference was not significant. Lower gestational age and male sex are risk factors for catheter colonization.

Aurora Kinase B Expression, Its Regulation and Therapeutic Targeting in Human Retinoblastoma

Purpose

Aurora kinase B (AURKB) plays a pivotal role in the regulation of mitosis and is gaining prominence as a therapeutic target in cancers; however, the role of AURKB in retinoblastoma (RB) has not been studied. The purpose of this study was to determine if AURKB plays a role in RB, how its expression is regulated, and whether it could be specifically targeted.

Methods

The protein expression of AURKB was determined using immunohistochemistry in human RB patient specimens and immunoblotting in cell lines. Pharmacological inhibition and shRNA-mediated knockdown were used to understand the role of AURKB in cell viability, apoptosis, and cell cycle distribution. Cell viability in response to AURKB inhibition was also assessed in enucleated RB specimens. Immunoblotting was employed to determine the protein levels of phospho-histone H3, p53, p21, and MYCN. Chromatin immunoprecipitation-qPCR was performed to verify the binding of MYCN on the promoter region of AURKB.

Results

The expression of AURKB was found to be markedly elevated in human RB tissues, and the overexpression significantly correlated with optic nerve and anterior chamber invasion. Targeting AURKB with small-molecule inhibitors and shRNAs resulted in reduced cell survival and increased apoptosis and cell cycle arrest at the G2/M phase. More importantly, primary RB specimens showed decreased cell viability in response to pharmacological AURKB inhibition. Additional studies have demonstrated that the MYCN oncogene regulates the expression of AURKB in RB.

Conclusions

AURKB is overexpressed in RB, and targeting it could serve as a novel therapeutic strategy to restrict tumor cell growth.