CD38-Specific Gallium-68 Labeled Peptide Radiotracer Enables Pharmacodynamic Monitoring in Multiple Myeloma with PET

The limited availability of molecularly targeted low-molecular-weight imaging agents for monitoring multiple myeloma (MM)-targeted therapies has been a significant challenge in the field. In response, a first-in-class peptide-based radiotracer, [68Ga]Ga-AJ206, is developed that can be seamlessly integrated into the standard clinical workflow and is specifically designed to noninvasively quantify CD38 levels and pharmacodynamics by positron emission tomography (PET). A bicyclic peptide, AJ206, is synthesized and exhibits high affinity to CD38 (KD: 19.1 ± 0.99 × 10-9 m) by surface plasmon resonance. Further, [68Ga]Ga-AJ206-PET shows high contrast within 60 min and suitable absorbed dose estimates for clinical use. Additionally, [68Ga]Ga-AJ206 detects CD38 expression in cell line-derived xenografts, patient-derived xenografts (PDXs), and disseminated disease models in a manner consistent with flow cytometry and immunohistochemistry findings. Moreover, [68Ga]Ga-AJ206-PET successfully quantifies CD38 pharmacodynamics in PDXs, revealing increased CD38 expression in the tumor following all-trans retinoic acid (ATRA) therapy. In conclusion, [68Ga]Ga-AJ206 exhibits the salient features required for clinical translation, providing CD38-specific high-contrast images in multiple models of MM. [68Ga]Ga-AJ206-PET could be useful for quantifying total CD38 levels and pharmacodynamics during therapy to evaluate approved and new therapies in MM and other diseases with CD38 involvement.

A Gallium-68-Labeled Peptide Radiotracer For CD38-Targeted Imaging In Multiple Myeloma With PET

PURPOSE

The limited availability of molecularly targeted low-molecular-weight imaging agents for monitoring multiple myeloma (MM)-targeted therapies has been a significant challenge in the field. In response, we developed [68Ga]Ga-AJ206, a peptide-based radiotracer that can be seamlessly integrated into the standard clinical workflow and is specifically designed to non-invasively quantify CD38 levels and pharmacodynamics by positron emission tomography (PET).

EXPERIMENTAL DESIGN

We synthesized a high-affinity binder for quantification of CD38 levels. Affinity was tested using surface plasmon resonance, and In vitro specificity was evaluated using a gallium-68-labeled analog. Distribution, pharmacokinetics, and CD38 specificity of the radiotracer were assessed in MM cell lines and in primary patient-derived myeloma cells and xenografts (PDX) with cross-validation by flow cytometry and immunohistochemistry. Furthermore, we investigated the radiotracer's potential to quantify CD38 pharmacodynamics induced by all-trans retinoic acid therapy (ATRA).

RESULTS

[68Ga]Ga-AJ206 exhibited high CD38 binding specificity (KD: 19.1±0.99 nM) and CD38-dependent In vitro binding. [68Ga]Ga-AJ206-PET showed high contrast within 60 minutes and suitable absorbed dose estimates for clinical use. Additionally, [68Ga]Ga-AJ206 detected CD38 expression in xenografts, PDXs and disseminated disease models in a manner consistent with flow cytometry and immunohistochemistry findings. Moreover, [68Ga]Ga-AJ206-PET successfully quantified CD38 pharmacodynamics in PDXs, revealing increased CD38 expression in the tumor following ATRA therapy.

CONCLUSIONS

[68Ga]Ga-AJ206 exhibited the salient features required for clinical translation, providing CD38-specific high contrast images in multiple models of MM. [68Ga]Ga-AJ206-PET could be useful for quantifying total CD38 levels and pharmacodynamics during therapy to evaluate approved and new therapies in MM and other diseases with CD38 involvement.

Non-invasive PD-L1 quantification using [18F]DK222-PET imaging in cancer immunotherapy

BACKGROUND

Combination therapies that aim to improve the clinical efficacy to immune checkpoint inhibitors have led to the need for non-invasive and early pharmacodynamic biomarkers. Positron emission tomography (PET) is a promising non-invasive approach to monitoring target dynamics, and programmed death-ligand 1 (PD-L1) expression is a central component in cancer immunotherapy strategies. [18F]DK222, a peptide-based PD-L1 imaging agent, was investigated in this study using humanized mouse models to explore the relationship between PD-L1 expression and therapy-induced changes in cancer.

METHODS

Cell lines and xenografts derived from three non-small cell lung cancers (NSCLCs) and three urothelial carcinomas (UCs) were used to validate the specificity of [18F]DK222 for PD-L1. PET was used to quantify anti-programmed cell death protein-1 (PD-1) therapy-induced changes in PD-L1 expression in tumors with and without microsatellite instability (MSI) in humanized mice. Furthermore, [18F]DK222-PET was used to validate PD-L1 pharmacodynamics in the context of monotherapy and combination immunotherapy in humanized mice bearing A375 melanoma xenografts. PET measures of PD-L1 expression were used to establish a relationship between pathological and immunological changes. Lastly, spatial distribution analysis of [18F]DK222-PET was developed to assess the effects of different immunotherapy regimens on tumor heterogeneity.

RESULTS

[18F]DK222-PET and biodistribution studies in mice with NSCLC and UC xenografts revealed high but variable tumor uptake at 60 min that correlated with PD-L1 expression. In MSI tumors treated with anti-PD-1, [18F]DK222 uptake was higher than in control tumors. Moreover, [18F]DK222 uptake was higher in A375 tumors treated with combination therapy compared with monotherapy, and negatively correlated with final tumor volumes. In addition, a higher number of PD-L1+ cells and higher CD8+-to-CD4+ cell ratio was observed with combination therapy compared with monotherapy, and positively correlated with PET. Furthermore, spatial distribution analysis showed higher [18F]DK222 uptake towards the core of the tumors in combination therapy, indicating a more robust and distinct pattern of immune cell infiltration.

CONCLUSION

[18F]DK222-PET has potential as a non-invasive tool for monitoring the effects of immunotherapy on tumors. It was able to detect variable PD-L1 expression in tumors of different cancer types and quantify therapy-induced changes in tumors. Moreover, [18F]DK222-PET was able to differentiate the impact of different therapies on tumors.

THE IMPACT OF CLIMATE CHANGE ON INFECTIOUS DISEASES: A COMPREHENSIVE ANALYSIS OF VECTOR-BORNE DISEASES, WATER-BORNE DISEASES, AND PUBLIC HEALTH STRATEGIES

Climate change is long-term modifications to weather patterns and a rise in extreme weather events. It might modify the hazard to human health and exacerbate current problems. The article explores the scientific data in a description of the effects of Infectious diseases in humans and climate change. It identifies scientific advancements and gaps in potential responses from human civilization and how it might prepare for the changes that come with it by adjusting to them. The impact reflects three aspects, such as climate variables, selected infectious diseases, and infectious disease components. This study demonstrates how vulnerable people are to any ill consequences that climate change may have on their health. Humans can actively influence controllable correlated health impacts by taking proactive measures, such as increasing our understanding of the detrimental effects associated with specific diseases and the patterns in climate change. We can also carefully distribute technology and resources, encouraging exercise and public awareness. It is advised to take the following adaption measures: Considering how infectious diseases and climate change are not the only things that science has discovered and create locally efficient early warning systems for those effects to produce more scientific justifications and go beyond scientific reports. Improve prediction of the spatiotemporal processes behind climate change and changes in infectious illnesses connected at different temporal and spatial scales.

Abstract 2768: Non-invasive detection of pancreatic adenocarcinoma using Ga-68 labelled epha2 targeting peptide

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease and early diagnosis is paramount for effective treatment. Molecular imaging techniques such as positron emission tomography (PET) could provide an early diagnosis of PDAC to potentially improve survival. EphA2, a member of Erythropoietin-producing hepatocellular (Eph) receptors, is a desirable target for PDAC detection as it is pro-oncogenic and expressed in > 90% of PDACs. Here, we report the development of a peptide-based PET imaging agent, [68Ga]AJ201, evaluation of its pharmacokinetics, and its potential to non-invasively detect variable EphA2 expression in moue models of PDAC.

Methods: A bicyclic peptide, AJ201, was synthesized and its binding affinity for EphA2 was determined by surface plasmon resonance (SPR). AJ201 was labelled with Gallium-68 in high radiochemical yields and purity. In vitro uptake of the resulting [68Ga]AJ201 was carried out in different PDAC cell lines with variable EphA2 expression (Panc1, CFPAC1, Hs766T, and SU8686) and Jurkat cell line as a negative control. In vivo pharmacokinetic properties of [68Ga]AJ201 were evaluated by PET-MR imaging and ex vivo biodistribution studies in different subcutaneous PDAC xenografts and in Panc1 orthotopic model (n=4-5/tumor). [68Ga]AJ201 in vivo specificity for EphA2 was confirmed by cross-correlative immunohistochemistry of xenografts and by co-injection of a blocking dose of non-radioactive AJ201 (1 mg/kg).

Results: AJ201 binds human EphA2 with high affinity (KD ~ 0.2 nM). Flow cytometry analysis confirmed variable EphA2 expression in all the PDAC cell lines tested with Panc1 and CFPAC cell lines exhibiting highest and lowest expression, respectively. In vitro binding assays showed variable [68Ga]AJ201 uptake in all the PDAC cells and almost no uptake in the presence of 1 µM non-radioactive AJ201 and in negative control Jurkat cells. In vivo dynamic PET-MR imaging revealed high and specific uptake of [68Ga]AJ201 in Panc1 tumor xenografts within 5 min and retained for at least 90 min. In contrast, [68Ga]AJ201 exhibited fast clearance from normal tissues resulting in high contrast images at 60 minutes and a high tumor-to-muscle ratio of 25.8 ± 6.7. [68Ga]AJ201 uptake in tumors was reduced by > 80 % in mice receiving blocking dose, confirming the specificity of the radiotracer. Also, [68Ga]AJ201 PET provided high contrast images of orthotopic Panc1 tumors. Furthermore, [68Ga]AJ201 PET showed variable and expression dependent uptake in all the PDAC xenografts tested that was corroborated by EphA2 expression detected by IHC.

Conclusion: [68Ga]AJ201 is an EphA2 specific high affinity peptide-based PET imaging agent that detects orthotopic PDAC in mouse models at 60 minutes and demonstrates potential to non-invasively detect PDAC in patients.

Citation Format: Ajay Kumar Sharma, Kuldeep Gupta, Akhilesh Mishra, Sophia Chen, Gabriela Lofland, Todd Armstrong, Edward Gabrielson, Lei Zheng, Elizabeth M. Jaffee, Sridhar Nimmagadda. Non-invasive detection of pancreatic adenocarcinoma using Ga-68 labelled epha2 targeting peptide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2768.

Venoms classification and therapeutic uses: a narrative review

The mere glimpse of venomous animals has always terrified humans because of the devastating effects of their venoms. However, researchers across the globe have isolated therapeutically active ingredients from these venoms and continue to explore them for drug leads. These efforts lead to the discovery of therapeutic molecules that the US-FDA has approved to treat different diseases, such as hypertension (Captopril), chronic pain (Ziconotide), and diabetes (Exenatide). The main active constituents of most venoms are proteins and peptides, which gained more attention because of advancements in biotechnology and drug delivery. The utilization of newer screening approaches improved our understanding of the pharmacological complexity of venom constituents and facilitated the development of novel therapeutics. Currently, with many venom-derived peptides undergoing different phases of clinical trials, more are in pre-clinical drug development phases. This review highlights the various sources of venoms, their pharmacological actions, and the current developments in venom-based therapeutics.

Gallium-68-labeled Peptide PET Quantifies Tumor Exposure of PD-L1 Therapeutics

PURPOSE

Immune checkpoint therapy (ICT) is currently ineffective in a majority of patients. Tumor drug exposure measurements can provide vital insights into mechanisms involved in the resistance of solid tumors to those therapeutics; however, tools to quantify in situ drug exposure are few. We have investigated the potential of programmed death-ligand 1 (PD-L1) pharmacodynamics, quantified using PET, to inform on the tumor exposure of anti-PD-L1 (aPD-L1) therapeutics.

EXPERIMENTAL DESIGN

To noninvasively quantify PD-L1 levels, we first developed a novel peptide-based gallium-68-labeled binder, [68Ga]Ga-DK223, and evaluated its in vivo distribution, pharmacokinetics, and PD-L1 specificity in preclinical models of triple-negative breast cancer and urothelial carcinoma with variable PD-L1 expression. We then quantified baseline and accessible PD-L1 levels in tumors as a noninvasive pharmacodynamic measure to assess tumor exposure to two aPD-L1 antibodies (avelumab and durvalumab).

RESULTS

DK223 exhibited a KD of 1.01±0.83 nmol/L for PD-L1 and inhibited the PD-1:PD-L1 interaction in a dose-dependent manner. [68Ga]Ga-DK223 provides high-contrast PET images within 60 minutes of administration and detects PD-L1 in an expression-dependent manner in xenograft models. PD-L1 pharmacodynamics measured using [68Ga]Ga-DK223-PET revealed that avelumab and durvalumab had similar exposure early during therapy, but only durvalumab exhibited sustained exposure at the tumor.

CONCLUSIONS

[68Ga]Ga-DK223 detected variable PD-L1 levels and exhibited salient features required for clinical translation. [68Ga]Ga-DK223-PET could be useful for quantifying total PD-L1 levels at baseline and accessible PD-L1 levels during therapy to understand drug exposure at the tumor, thus supporting its use for guiding and optimizing ICT.

Phytochemical Analysis and Demonstration of Antioxidant, Antibacterial, and Antibiofilm Activities of Ethnomedicinal Plants of North East India

Ethnomedicinal plants are a rich reservoir of active compounds with potent pharmacological properties. Therefore, plants could serve as a source for the discovery of active antimicrobial and antioxidant agents and are focused because of their low toxicity, economic viability, easy availability, etc. In this regard, phytochemical analyses, viz. β-carotene, total sugar, reducing sugar, vitamin C, total carotenoids, protein, total phenolic content (TPC), and total flavonoid content (TFC) of 20 ethnomedicinal plants of North East India (NEI) were evaluated in this study. The antibacterial activity against human pathogens and antioxidant potential of plant extracts was also demonstrated. The minimum inhibitory concentration (MIC₈₀), minimum bactericidal concentration (MBC), and total antibacterial activity (TAA) of the active extracts were evaluated against Pseudomonas aeruginosa and Chromobacterium violaceum. The active extracts were also examined for antibiofilm as well as anti-pyocyanin activities against P. aeruginosa and anti-QS activity against C. violaceum at sub-MICs. The study demonstrated variable concentration of phytochemicals of the extracts, viz. β-carotene (0.29-8.91 mg g^-1), total sugar (2.92-30.6 mM), reducing sugar (0.44-14.5 mM), vitamin C (8.41-31.3 mg g^-1), total carotenoids (14.9-267.0 mg g^-1), protein (5.65-283 mg g^-1), TPC (5.32-31.0 mg GAE/g DW), and TFC (1.74-68.2 mg QE/g DW). The plant extracts also exhibited potent antioxidant and antibacterial activities against both Gram-positive and Gram-negative bacteria. Some of the extracts also demonstrated significant biofilm inhibition and eradication, anti-pyocyanin, and anti-QS activities at sub-MICs. The selected ethnomedicinal plants are rich in phytochemicals and demonstrated potent antioxidant, antibacterial, and antibiofilm activities, thus could serve as the important source of novel antioxidant and antimicrobial agents.

Independent prognostic value of ventricular premature complexes during exercise and recovery in asymptomatic patients: a meta-analysis of observational studies

Introduction

Ventricular premature contractions (VPCs) are a common finding during a cardiac stress test. The independent prognostic value of these findings in asymptomatic participants is not clear.

Purpose

To investigate the cumulative independent prognostic value of VPC for adverse outcomes.

Methods

We conducted a systematic review and meta-analysis of observational studies in the following databases: MEDLINE, Embase®, and Cochrane Central from inception till January 28, 2022. The primary outcome was the cumulative hazard of all-cause mortality with VPCs during exercise or recovery in asymptomatic participants. The secondary outcome was cardiovascular mortality. We stratified results based on VPC during exercise or recovery.

We included studies with participants with no known CV disease and known CV disease. If there was known CV disease at baseline, the study should have adjusted for at least ≥1 known confounder. If a study reported low risk or higher risk VPCs, we included outcomes with higher risk VPCs to make the data comparable across literature. Random effect meta-analyses were used to predict cumulative hazard ratios. The review was registered with PROSPERO (registration number CRD42022297028)

Results

We found 10 studies with 47,497 participants that met our inclusion criteria (8 studies with all-cause and CV mortality, 2 studies with CV mortality only). Three studies included patients with baseline CV disease (proportion 12–33%). Follow-up duration ranged from 5.3 to 20.3 years. Definition of VPCs differed in the individual studies.

Both VPCs during exercise and recovery were associated with a higher hazard of all-cause mortality (HR 1.21, 95% confidence interval [CI] 1.07, 1.34 and 1.32, 95% CI 1.06, 1.58, p<0.001 and low heterogeneity for both, respectively, Figure 1A). There was no small study treatment effect bias.

Similarly, both VPCs during exercise and recovery were associated with a higher hazard of CV mortality (HR 1.63, 95% CI 1.30, 1.96 and 1.68, 95% CI 1.00, 2.35, p<0.001, and low heterogeneity for both, respectively, Figure 1B).

The presence of VPC had a numerically stronger association with CV mortality than all-cause mortality. VPCs during recovery seem to have more prognostic value than VPC during rest.

Conclusion

After adjusting for known confounders, VPCs during exercise and recovery predict a higher risk of all-cause and CV mortality. The risk is higher with VPCs during recovery.

Funding Acknowledgement

Type of funding sources: None.

Ecofriendly phytofabrication of silver nanoparticles using aqueous extract of Cuphea carthagenensis and their antioxidant potential and antibacterial activity against clinically important human pathogens

The green synthesis of nanoparticles (NPs) is the safest, ecofriendly, cost-effective, and non-hazardous approach of nanotechnology. In the current study, we described the green synthesis of silver nanoparticles (AgNPs) using Cuphea carthagenensis aqueous leaf extract as a reducing, capping, and stabilizing agent. The study aims at the synthesis, characterization, optimization, and determination of the antibacterial activity of Cc-AgNPs against clinically important human pathogens. Coating of cotton fabrics with Cc-AgNPs and their efficacy against skin infection causing organisms was also evaluated. Furthermore, antioxidant activity, growth assay and time kill assay of Cc-AgNPs were also performed in the study. The biosynthesized Cc-AgNPs were characterized by UV-visible spectrometry, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The spectroscopic and microscopic analysis demonstrated biosynthesis of face-centered cubic (fcc) crystalline spherical Cc-AgNPs with an average particle size of 10.65 ± 0.1 nm. Optimized peak synthesis of Cc-AgNPs was reported at pH7, 55 °C, 4 mM silver nitrate, and 5:45 (plant extract: silver nitrate). Cc-AgNPs exhibited potent antioxidant effect and antibacterial activity against both Gram-positive and Gram-negative bacteria. The lowest MIC (15 μg/ml) and MBC (25 μg/ml) values were reported against S. typhimurium. The Cc-AgNPs coated fabrics demonstrated potent antibacterial activity against tested strains. This application could be helpful in wound healing management. Furthermore, the hemolytic analysis demonstrated that Cc-AgNPs exhibit non-toxic nature against Red Blood Cells (RBCs) at the tested concentrations. In conclusion, the investigation demonstrated a fast, stable, and eco-friendly approach to the biosynthesis of Cc-AgNPs along with their antibacterial and antioxidant properties.

Diagnostic Tools for Rapid Screening and Detection of SARS-CoV-2 Infection

The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has severely impacted human health and the health management system globally. The ongoing pandemic has required the development of more effective diagnostic strategies for restricting deadly disease. For appropriate disease management, accurate and rapid screening and isolation of the affected population is an efficient means of containment and the decimation of the disease. Therefore, considerable efforts are being directed toward the development of rapid and robust diagnostic techniques for respiratory infections, including SARS-CoV-2. In this article, we have summarized the origin, transmission, and various diagnostic techniques utilized for the detection of the SARS-CoV-2 virus. These higher-end techniques can also detect the virus copy number in asymptomatic samples. Furthermore, emerging rapid, cost-effective, and point-of-care diagnostic devices capable of large-scale population screening for COVID-19 are discussed. Finally, some breakthrough developments based on spectroscopic diagnosis that could revolutionize the field of rapid diagnosis are discussed.

Abstract 2477: PD-L1 PET quantifies the pharmacodynamic effects of immunotherapy

Introduction: Immune checkpoint protein targeted therapeutics have transformed cancer treatment but only a subset of patients derive benefit. To improve efficacy, a variety of combination therapies are being studied. Programmed death ligand-1 (PD-L1) immunohistochemistry (IHC) is used as a biomarker to guide many of those therapies. Non-invasive evaluation of therapy induced changes in PD-L1 levels in the whole body could provide insights to guide those therapies. Here, we investigated the potential of [18F]DK222, a novel PD-L1 binding positron emission tomography (PET) imaging agent, to quantify PD-L1 levels and pharmacodynamics in humanized mouse modes.

Methods: Non-small cell lung cancer (NSCLC), urothelial carcinoma (UC) and melanoma cell lines were screened by flow cytometry (FC) for PD-L1 expression and density. In vitro cell uptake assays, in vivo PET imaging and ex vivo biodistribution studies were used to evaluate the specificity of [18F]DK222 to bind PD-L1 (n=5-6/tumor). To quantify immunotherapy induced changes in PD-L1, A375 melanoma xenografts were inoculated in NSG mice humanized with CD34+ cells. Mice were treated with either 5 mg/kg anti- PD-1; (pembrolizumab) or 5 mg/kg of anti-PD-1 + 4 mg/kg of anti- CTLA-4 (ipilimumab) (n=5) and [18F]DK222 PET was acquired before and 7 days after start of treatment. Tumor growth was monitored. FC of tumors was performed to measure changes in TME and immune cell infiltrates.

Results: In vitro uptake of [18F]DK222 in NSCLC (H244 > H226 > A549) and UC (BFTC909 > T24 > SCaBER) correlated with PD-L1 density (R2=0.96). [18F]DK222 PET and biodistribution studies in mice with NSCLC and UC xenografts revealed high and variable tumor uptake at 60 min, which was in agreement with PD-L1 levels detected by IHC. These data established sensitivity of [18F]DK222 PET to quantify variable PD-L1 levels in vivo. We next sought to quantify therapy induced changes in PD-L1 levels. We observed higher [18F]DK222 uptake in tumors of mice treated with combination therapy compared to monotherapy (1.83 vs 0.47 %ID/cc). A significant delay in tumor growth was observed with combination therapy compared to monotherapy. Two out of five mice with highest increase in [18F]DK222 uptake in combination therapy group exhibited least tumor growth. Also, final tumor volumes negatively correlated with [18F]DK222 uptake (R2=0.33) irrespective of treatment regimen. FC analysis showed higher immune infiltrates (1320 vs 230 per milligram of tumor), PD-L1+ cells (6005 vs 2739/mg) and ratio of CD8+ to CD4+ cells (1.94 vs 0.47) in tumors treated with combination therapy compared with monotherapy. These observations confirmed that immunotherapy induced changes in PD-L1 levels in tumors can be quantified using [18F]DK222 PET.

Conclusion: [18F]DK222 PET can effectively quantify variable PD-L1 levels in tumors. Moreover, [18F]DK222 PET exhibits the sensitivity to quantify PD-L1 pharmacodynamics to inform on tumor response to therapy.

Citation Format: Akhilesh Mishra, Dhiraj Kumar, Kuldeep Gupta, Patrick M. Forde, Edward Gabrielson, Sridhar Nimmagadda. PD-L1 PET quantifies the pharmacodynamic effects of immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2477.

Abstract 2481: Imaging pancreatic ductal adenocarcinoma using an EphA2 receptor tyrosine kinase binding 68Ga-labeled peptide radiotracer

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is difficult to diagnose and has dismal survival rates. Molecular imaging techniques such as positron emission tomography (PET) could fulfill an unmet need and enable an early diagnosis of PDAC to potentially improve survival. EphA2, a member of Erythropoietin-producing hepatocellular (Eph) receptors, plays a pivotal role in the tumorigenesis and development of an immune suppressive microenvironment in PDAC. We therefore developed a peptide-based PET imaging agent for EphA2, [68Ga]AJ201, and evaluated its pharmacokinetics and potential to non-invasively quantify variable EphA2 expression in PDAC.

Methods: A Gallium-68 labeled EphA2 binding peptide, [68Ga]AJ201, was synthesized in high radiochemical yields and purity. Surface plasmon resonance (SPR) analysis was carried out to measure binding affinity. EphA2 expression was assessed in PDAC cell lines and tissues in CCLE and TCGA. EphA2 expression in seven PDAC cell lines (Panc1, AsPC1 BxPC3, CFPAC1, Hs766T, Panc1005, and SU8686) was validated by RT-qPCR and flow cytometry. Those cell lines were then used for in vitro binding assays and the corresponding xenografts in NSG mice for PET imaging and ex vivo biodistribution studies (n=4-5/tumor). Specificity of [68Ga]AJ201 was confirmed by co-injection of a blocking dose of non-radioactive AJ201 (1 mg/kg).

Results: SPR analysis showed that AJ201 binds EphA2 with a high affinity (KD) of 0.2 nM. TCGA analysis revealed higher expression of EphA2 in PDAC vs healthy tissues. Flow cytometry analysis revealed high and variable EphA2 expression in all the PDAC cell lines tested with Panc1 exhibiting the highest levels. In vitro binding assays showed high and variable [68Ga]AJ201 uptake in all the PDAC cell lines and low uptake in the presence of 1µM non-radioactive AJ201 and in EphA2 negative Jurkat cells. Pharmacokinetics of [68Ga]AJ201 in mice with Panc1 tumors showed high contrast images of EphA2 expression at 60 minutes with a tumor/muscle ratio of 25.9±6.7. That high tumor uptake was significantly reduced in mice receiving blocking dose confirming the specificity of the radiotracer. Also, [68Ga]AJ201 PET quantified variable EphA2 expression in all the seven PDAC xenografts tested, with highest uptake observed in Panc1 tumor, followed by SU8686, and lowest in CFPAC1. Ex vivo biodistribution studies corroborated PET imaging findings.

Conclusion: [68Ga]AJ201 is a EphA2 specific high affinity peptide-based PET imaging agent that provides high contrast PET images of PDAC by 60 minutes. [68Ga]AJ201 PET has the potential to non-invasively detect PDAC in patients.

Citation Format: Kuldeep Gupta, Ajay Kumar Sharma, Akhilesh Mishra, Sophia Y. Chen, Gabi Lofland, Todd M. Armstrong, Lei Zhang, Elizabeth M. Jaffee, Sridhar Nimmagadda. Imaging pancreatic ductal adenocarcinoma using an EphA2 receptor tyrosine kinase binding 68Ga-labeled peptide radiotracer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2481.

Use of pulse oximetry during nitrous oxide- oxygen inhalation sedation: mandatory or recommended?

AIM

There is skepticism amongst many dentists about the interference of nitrous oxide with the physiological parameters. This commentary attempts to make clear recommendations on the use of pulse oximeter during nitrous oxide inhalation sedation.

BACKGROUND

Nitrous oxide is used commonly in dentistry as a tool to reduce fear/ anxiety and build a positive dental attitude. Dentists use pulse oximeter to monitor oxygen saturation during the period of administration of nitrous oxide. There is no consensus amongst various guidelines across the world on the necessity of using pulse oximeter during the period of administration of nitrous oxide CONCLUSION: Pulse oximetry may not be considered mandatory when nitrous oxide gas is being administered for minimal sedation to a healthy patient having no pre- existing diseases/illness.

Lung Function Tests in Hairdressers of Gangtok: A Cross-Sectional Study

Background

Hairdressers undergo extensive and prolonged exposure to a variety of chemical substances present in the air in their salons. Although in low concentrations, the various products used for hair care are harmful as most of these products generate chemical aerosols during different procedures. These aerosols which have irritant or sensitizing effects on respiratory mucosa have been found to enter into the airways.

Aim

The aim of this study is to assess the impairment of lung function in hairdressers in Gangtok.

Method

This is a cross-sectional, comparative study conducted on 50 hairdressers and 50 age- and sex-matched non-hairdresser comparison group. The sampling technique used was simple random sampling. Permission from Institutional Ethical Committee was obtained before beginning the study. A standard questionnaire was used to record the respiratory symptoms. The pulmonary function parameters of the subjects were measured using portable spirometer HELIOS 720.

Results

All the parameters were decreased in hairdressers and almost all the differences were statistically significant. FEV1 (P = 0.023) and FEV1/FVC ratio (P < 0.05) were reduced significantly. FEF25-75% and PEFR were also significantly reduced (P < 0.05 in both parameters). FVC was also reduced in hairdressers, but it was not statistically significant (P = 0.342).

Conclusion

Hairdressers undergo exposure to different chemicals in their workplace and carry the risk of decreased pulmonary function.

Assessment of prescribing pattern of drugs and completeness of prescriptions as per the World Health Organization prescribing indicators in various Indian tertiary care centers: A multicentric study by Rational Use of Medicines Centers-Indian Council of Medical Research network under National Virtual Centre Clinical Pharmacology activity

OBJECTIVE

The rational use of medicines as per the World Health Organization (WHO) should be practiced globally. However, data regarding the completeness of the prescriptions and their rational use is lacking from developing countries like India. Thus, the aim of this study was to assess the prescribing patterns of drugs and completeness of prescriptions as per WHO core drug use and complementary indicators to provide real-life examples for the Indian Council of Medical Research (ICMR) online prescribing skill course for medical graduates.

METHODS

Prescriptions of the patients, fulfilling inclusion criteria, attending Outpatient Departments of various specialties of tertiary care hospitals, were collected by thirteen ICMR Rational use of medicines centers located in tertiary care hospitals, throughout India. Prescriptions were evaluated for rational use of medicines according to the WHO guidelines and for appropriateness as per standard treatment guidelines using a common protocol approved by local Ethics committees.

RESULTS

Among 4838 prescriptions, an average of about three drugs (3.34) was prescribed to the patients per prescription. Polypharmacy was noted in 83.05% of prescriptions. Generic drugs were prescribed in 47.58% of the prescriptions. Further, antimicrobials were prescribed in 17.63% of the prescriptions and only 4.98% of prescriptions were with injectables. During the prescription evaluation, 38.65% of the prescriptions were incomplete due to multiple omissions such as dose, duration, and formulation.

CONCLUSION

Most of the parameters in the present study were out of the range of WHO-recommended prescribing indicators. Therefore, effective intervention program, like training, for the promotion of rational drug use practice was recommended to improve the prescribing pattern of drugs and the quality of prescriptions all over the country.

Metachronous isolated inferior vena cava tumour thrombus in renal cell cancer: a rare aftermath

Renal cell cancer (RCC) accounts for 3% of all solid malignancies. Synchronous tumour thrombus in the renal vein or inferior vena cava is reported in 4-10% cases and is a surgical challenge. Contemporary imaging modalities that are used to define the presence and extent of venous thrombus include colour Doppler, contrast-enhanced computed tomography and magnetic resonance venography. Surgical management depends upon the degree of tumour thrombus. We report isolated recurrence of RCC in the inferior vena cava 2 years after radical nephrectomy, and discuss its pathophysiology and management.

Microbial biofilm: formation, architecture, antibiotic resistance, and control strategies

The assembly of microorganisms over a surface and their ability to develop resistance against available antibiotics are major concerns of interest. To survive against harsh environmental conditions including known antibiotics, the microorganisms form a unique structure, referred to as biofilm. The mechanism of biofilm formation is triggered and regulated by quorum sensing, hostile environmental conditions, nutrient availability, hydrodynamic conditions, cell-to-cell communication, signaling cascades, and secondary messengers. Antibiotic resistance, escape of microbes from the body's immune system, recalcitrant infections, biofilm-associated deaths, and food spoilage are some of the problems associated with microbial biofilms which pose a threat to humans, veterinary, and food processing sectors. In this review, we focus in detail on biofilm formation, its architecture, composition, genes and signaling cascades involved, and multifold antibiotic resistance exhibited by microorganisms dwelling within biofilms. We also highlight different physical, chemical, and biological biofilm control strategies including those based on plant products. So, this review aims at providing researchers the knowledge regarding recent advances on the mechanisms involved in biofilm formation at the molecular level as well as the emergent method used to get rid of antibiotic-resistant and life-threatening biofilms.

The SARS-CoV-2 Spike protein alters human cardiac pericyte function and interaction with endothelial cells through a non-infective mechanism involving activation of CD147 receptor signalling

Background

Human cardiac pericytes (PC) were proposed as the main cellular target for SARS-CoV-2 in the heart due to high transcriptional levels of the angiotensin-converting enzyme 2 (ACE2) receptor. Emerging reports indicate CD147/Basigin (BSG), highly expressed in endothelial cells (EC), is an alternative SARS-CoV-2 receptor. To date, the mechanism by which the virus infects and disrupts the heart vascular cells was not identified yet. Moreover, cleaved Spike (S) protein molecules could be released into the bloodstream from the leaking pulmonary epithelial-endothelial barrier in patients with severe COVID-19, opening to the possibility of non-infective diseases in organs distant from the primary site of infection.

Purposes

(1) to confirm that human primary cardiac PC express ACE2 and CD147; (2) to verify if PC are permissible to SARS-CoV-2 infection; (3) to investigate if the recombinant SARS-CoV-2 S protein alone, without the other viral elements, can trigger molecular signalling and induce functional alterations in PC; (4) to explore which viral receptor is responsible for the observed events.

Methods and results

Cardiac PC express both the ACE2 and CD147 receptors at mRNA and protein level. Incubation of PC for up to 5 days with SARS-CoV-2 expressing the green fluorescent protein (GFP) did not show any evidence of cell infection or viral replication. Next, we exposed the PC to the recombinant S protein (5.8 nM) and confirmed that the protein engaged with cellular receptors (western blot analysis of S protein in treated and control PC). Incubation with the S protein increased PC migration (wound closure assay, P&lt;0.01 vs ctrl) and reduced the formation of tubular structures between PC and EC in a Matrigel assay (P&lt;0.01 vs ctrl). Moreover, the S protein promoted the production of pro-inflammatory factors typical of the cytokine storm in PC (ELISA measurement of MCP1, IL-6, IL-1β, TNFα, P&lt;0.05 vs ctrl), and induced the secretion of pro-apoptotic factors responsible for EC death (Caspase 3/7 assay, P&lt;0.05 vs ctrl). Signalling studies revealed that the S protein triggers the phosphorylation/activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) through the CD147 receptor, but not ACE2, in cardiac PC. The neutralization of CD147, using a blocking antibody, prevented ERK1/2 activation in PC, and was reflected into a partial rescue of the cell functional behaviour (migration and pro-angiogenic capacity). In contrast, blockage of CD147 failed to prevent the pro-inflammatory response in PC.

Conclusions

We propose the novel hypothesis that COVID-19 associated heart's microvascular dysfunction is prompted by circulating S protein molecules rather than by the direct coronavirus infection of PC. Besides, we propose CD147, and not ACE2, as the leading receptor mediating S protein signalling in cardiac PC.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): BHF project grant “Targeting the SARS-CoV-2 S-protein binding to the ACE2 receptor to preserve human cardiac pericytes function in COVID-19” BHF Centre for Vascular Regeneration II

516 Does the Use of Adjuvant Chemotherapy Increase Incisional Hernia Rates in Colorectal Cancer Patients – A Retrospective Single Centre Cohort Study

Aim

Incisional hernias (IH) are a known complication of any major abdominal surgery. It is known that chemotherapy impairs healing processes via delayed inflammation, impaired collagen synthesis and reduced fibrin deposition and wound contraction. There are currently, to our knowledge, no trials examining the effect of adjuvant chemotherapy on incidence of IH in patients with colorectal cancer. This study aims to assess the same by comparing IH rates between chemotherapy and non-chemotherapy patient groups.

Method

All the patients who had major surgery for colorectal cancer between January 2009 and January 2014 were divided into two groups of chemotherapy (A) and non-chemotherapy (B). Records of first 160 patients from each group were retrospectively analysed.

Results

There were non-significant differences between groups for sex, tumour location, primary operation, and type of procedure (emergency or elective). Significant differences were observed for age (more elder patients in group B, p = 0.000011), method of access (more open procedures in group B and more laparoscopic procedures in group A, p = 0.0007) and Charlson co-morbidity scores (more advanced score in group B, p = 0.029). We found that 21/120 (21.21%) patients in the chemotherapy group and 12/99 (13.79%) patients in non-chemotherapy group developed Incisional hernias. Although there was a higher rate of IH in the chemotherapy group, this was not statistically significant (p = 0.27).

Conclusions

Although this study fails to demonstrate any statistically significant difference in IH incidence between two groups, but this study can act as a pilot in order to fuel further high-quality research to draw more valid conclusions.

Delineating the Role of Aedes aegypti ABC Transporter Gene Family during Mosquito Development and Arboviral Infection via Transcriptome Analyses

Aedes aegypti acts as a vector for several arboviral diseases that impose a major socio-economic burden. Moreover, the absence of a vaccine against these diseases and drug resistance in mosquitoes necessitates the development of new control strategies for vector-borne diseases. ABC transporters that play a vital role in immunity and other cellular processes in different organisms may act as non-canonical immune molecules against arboviruses, however, their role in mosquito immunity remains unexplored. This study comprehensively analyzed various genetic features of putative ABC transporters and classified them into A-H subfamilies based on their evolutionary relationships. Existing RNA-sequencing data analysis indicated higher expression of cytosolic ABC transporter genes (E & F Subfamily) throughout the mosquito development, while members of other subfamilies exhibited tissue and time-specific expression. Furthermore, comparative gene expression analysis from the microarray dataset of mosquito infected with dengue, yellow fever and West Nile viruses revealed 31 commonly expressed ABC transporters suggesting a potentially conserved transcriptomic signature of arboviral infection. Among these, only a few transporters of ABCA, ABCC and ABCF subfamily were upregulated, while most were downregulated. This indicates the possible involvement of ABC transporters in mosquito immunity.

Implementation of an acute tonsillitis management protocol within a clinical decisions unit

INTRODUCTION

With tonsillectomy surgery subject to increasingly strict commissioning criteria over the past 20 years in the UK, the total number of admissions for acute tonsillitis has been rising steadily. Multiple single-centre studies have demonstrated how introduction of a standardised management protocol can be effective in improving the delivery of treatment for acute tonsillitis in the emergency department.

METHODS

Using a novel approach, we aimed to implement an acute tonsillitis management protocol within a formal clinical decisions unit (CDU) pathway. Following a retrospective baseline audit, we carried out two post-intervention cycles of data collection to assess safety and efficacy.

RESULTS

The median number of initial treatments increased significantly from two of five at baseline, to three of five in both the first (U = 86, p = 0.004) and second (z = 2.959, p = 0.003) audit cycles. Admission rate was reduced from 0.79 to 0.44 in the first cycle, representing a 44.6% relative risk reduction [95% confidence interval (CI) 0.304-1.012; p = 0.0547]. Admission rate remained reduced at 0.48 in the second cycle, with a relative risk reduction of 39.2% compared with baseline (95% CI 0.380-0.972; p = 0.038).

CONCLUSIONS

Utilisation of the CDU led to an improvement in the delivery of initial treatment, an extended period of observation and subsequently a greater percentage of patients being discharged. An acute tonsillitis management protocol within a CDU appears to be a safe and effective model and is now standard practice in our hospital.

Comparative evaluation of the conventional tube test and column agglutination technology for ABO antibody titration in healthy individuals: a report from India

Determination of accurate anti-A/-B titers is important for treatment selection in ABO-incompatible stem cell and solid-organ transplants. The standard method for ABO antibody titration is the conventional tube test (CTT). Dithiothreitol (DTT) is commonly used to inactivate the IgM antibody component. The aim of this study was to compare six different methods for ABO antibody titration and to observe the effectiveness of DTT on antibody estimation. A total of 90 healthy voluntary blood donors were enrolled in this study, including 30 each for blood groups A, B, and O. Antibody titrations were performed and tested using the CTT-immediate spin (IS), CTT-antihuman globulin (AHG) with and without DTT, column agglutination technology (CAT)-IS, and CAT-AHG with and without DTT methods. Bead-CAT was used, and the positive cutoff value was set to 1+ for each method to determine the endpoint of the titer. The median values of anti-A/-B titers by IS were found to be higher than those values by AHG in CTT and CAT among group B and A individuals, whereas no statistically significant differences were observed in values from group O individuals for IS and AHG anti-A/-B titers, estimated by each method. Although there was positive correlation between the anti-A/-B titer results obtained using the CTT and CAT in all blood groups, testing using AHG showed poor agreement with and without DTT pretreatment (kappa value of 0.11 and 0.20, respectively). Moderate agreement was observed between CTT-IS and CAT-IS (kappa value of 0.46). Median anti-A/-B AHG titers were reduced by the use of DTT in all blood group samples. Significant differences in the interpretability of anti-A/-B titers were observed among different methods. A uniform approach for selecting the method for ABO antibody titration is highly recommended, and DTT pretreatment of plasma to neutralize IgM activity should be considered to obtain precise values of IgG anti-A/-B titers. Immunohematology 2021;37:25-32 .

Determination of accurate anti-A/-B titers is important for treatment selection in ABO-incompatible stem cell and solid-organ transplants. The standard method for ABO antibody titration is the conventional tube test (CTT). Dithiothreitol (DTT) is commonly used to inactivate the IgM antibody component. The aim of this study was to compare six different methods for ABO antibody titration and to observe the effectiveness of DTT on antibody estimation. A total of 90 healthy voluntary blood donors were enrolled in this study, including 30 each for blood groups A, B, and O. Antibody titrations were performed and tested using the CTT-immediate spin (IS), CTT-antihuman globulin (AHG) with and without DTT, column agglutination technology (CAT)-IS, and CAT-AHG with and without DTT methods. Bead-CAT was used, and the positive cutoff value was set to 1+ for each method to determine the endpoint of the titer. The median values of anti-A/-B titers by IS were found to be higher than those values by AHG in CTT and CAT among group B and A individuals, whereas no statistically significant differences were observed in values from group O individuals for IS and AHG anti-A/-B titers, estimated by each method. Although there was positive correlation between the anti-A/-B titer results obtained using the CTT and CAT in all blood groups, testing using AHG showed poor agreement with and without DTT pretreatment (kappa value of 0.11 and 0.20, respectively). Moderate agreement was observed between CTT-IS and CAT-IS (kappa value of 0.46). Median anti-A/-B AHG titers were reduced by the use of DTT in all blood group samples. Significant differences in the interpretability of anti-A/-B titers were observed among different methods. A uniform approach for selecting the method for ABO antibody titration is highly recommended, and DTT pretreatment of plasma to neutralize IgM activity should be considered to obtain precise values of IgG anti-A/-B titers. Immunohematology 2021;37:25–32 .

908 Personal Protective Equipment (PPE) Guidance During A Global Pandemic: A Statistical Analysis of National Perceived Confidence, Knowledge, And Educational Deficits Amongst U.K. Based Doctors

Introduction

March 11th, 2020 saw the World Health Organisation declare a global pandemic following the eruption of the novel coronavirus disease 2019. Unprecedented global demand for personal protective equipment (PPE) was complicated by limited availability and conflicting guidance from healthcare bodies. This study aimed to assess perceived confidence and knowledge of Public Health England’s PPE guidance amongst doctors of varying specialties and grades.

Method

A nationwide 11-point survey comprising of multiple-choice questions (MCQs) and a Likert scale assessing perceived confidence (1=not confident, 5=very confident) was disseminated to U.K. based doctors using multiple platforms.

Results

Data collated from 697 respondents revealed average perceived confidence was low. Notably, 59% felt they had received insufficient education regarding up-to-date guidance, with 81% advocating further training. Anaesthetics and ophthalmology were the highest and lowest scoring specialties in knowledge based MCQs, achieving 59% and 31% respectively. Subsequent statistical analysis revealed significant differences between specialties."

Conclusions

Ensuring consistency in published PPE guidance and education can develop doctor’s confidence and knowledge of appropriate PPE use. The absence of a unified consensus and global education regarding the use of PPE poses significant ramifications for patient and healthcare professional (HCP) safety whilst risking further depletion of already sparse resources.

Ultrasound-guided sacral multifidus plane block for analgesia following excision of sacrococcygeal teratoma in two neonates

Peri-operative pain management in the neonate with a sacrococcygeal teratoma poses significant challenges to the anaesthetist. Involvement of the sacrococcygeal area by the tumour often prevents the use of conventional regional anaesthetic techniques such as caudal or epidural analgesia, with a subsequent reliance on intravenous opioids and paracetamol. Since opioids are associated with respiratory depression, constipation and urinary retention, there is high incidence of opiophobia with consequent inappropriate dosage prescription, particularly in the paediatric population. We describe the use of an ultrasound-guided sacral multifidus plane block in two neonates undergoing surgical excision of sacrococcygeal teratoma. The block is technically easy to perform and also avoids traversing critical structures. Hence, it may be regarded as a promising analgesic technique for painful interventions in the sacrococcygeal area.

Psychological assessment and lived experiences of recovered COVID-19 patients who presented for convalescent plasma donation

Background

Increasingly, it has been seen that patients recovering from COVID-19 may face a second battle of coping with its mental health ramifications. These psychological issues can even be experienced by patients who were asymptomatic or had mild to moderate symptoms, potentially impacting their quality of life.

Methodology

This was a prospective observational study to analyse the psychological impact of COVID-19 in recovered patients who presented as prospective convalescent plasma (CP) donors. An interview for the psychological assessment of the prospective donors was carried out. Depression and anxiety in the participants were assessed by HAM-A, and HAM-D scores and Quality of Life were assessed using the WHOQOL-BREF scale.

Results

A total of 51 prospective donors were assessed, with a mean age of 34.37 (±9.08) years, with the majority being males (46). No clinically significant depression and anxiety were found on the basis of HAM-D and HAM-A scores. The worst affected quality of life parameter, based on the WHOQOL-BREF scale, was physical quality of life followed by environmental, psychological, and social relationships. Moreover, due to infection, social stigma was experienced by 49.02% of the donors, while 21.97% had anxiety related to convalescent plasma donation as a common livid experience.

Conclusion

Poor quality of life and social stigma during the recovery phase is prevalent in COVID-19 recovered patients, for which formulation of holistic support strategies are the need of the hour.

Inhibition of biofilm and quorum sensing-regulated virulence factors in Pseudomonas aeruginosa by Cuphea carthagenensis (Jacq.) J. F. Macbr. Leaf extract: An in vitro study

ETHNOPHARMCOLOGICAL RELEVANCE

Microbial biofilm formation, a quorum sensing (QS) regulated process, is one of the major causes of nosocomial and chronic infections, foodborne diseases, and associated deaths. Various approaches have been used to eradicate the menace of biofilm. Ethnomedicinal plants as potent antibiofilm agents are gaining a lot of interest in an era where the drug resistance is increasing and the availability of potent antibiotics is no longer promised. In this context, the methanol extract of Cuphea carthagenensis (CCMD), an ethno-medicinal and culinary herb, was evaluated as an antibiofilm and anti-QS agent against Pseudomonas aeruginosa.

AIM OF THE STUDY

The aim of the study is to evaluate the antibiofilm and anti-QS activity of an ethnomedicinal plant against a strong biofilm forming microorganism, P. aeruginosa.

METHODS

Antibiofilm activity of CCMD was demonstrated at different concentrations by Tissue Culture Plate, Test Tube method and other microscopic techniques. The effect of CCMD on QS and QS-related virulence factors viz. Pyocyanin, exopolymeric substance matrix (EPS), total protease, elastase, pyoverdin and swimming motility in P. aeruginosa were also evaluated. Antioxidant activity (DPPH & FRAP), total phenolic and flavonoid content were also checked. In order to determine the composition of the extract HPLC analysis was also performed.

RESULTS

In vitro study demonstrated a significant inhibition of biofilm formation (81.88 ± 2.57%) as well as production of QS-dependent virulence factors in P. aeruginosa. The extract also inhibited violacein production (83.31 ± 2.77%) in Chromobacterium violaceum which correlates with the reduction in QS-mediated virulence factors. The extract showed 64.79% ± 0.83% DPPH scavenging activity and reduction of ferricyanide complex (Fe³⁺) to the ferrous form (Fe²⁺) in DPPH and FRAP assay, respectively. Furthermore, the extract showed thermal stability and does not have any growth inhibitory effect on P. aeruginosa. The HPLC analysis demonstrated the presence of ellagic acid, ascorbic acid and hippuric acid in the extract.

CONCLUSION

This work is the first to demonstrate that C. carthagenensis can attenuate biofilm formation and QS-mediated virulence factors of P. aeruginosa. Further investigation is required to use this ethnomedicinal plant (CCMD) as an important source of antibiofilm agents.

Cognitive Performance and Neuro-Metabolites in HIV Using 3T Magnetic Resonance Spectroscopy: A Cross-Sectional Study from India

BACKGROUND

Cognitive impairment in patients with human immunodeficiency virus (HIV) is associated with higher morbidity. The prevalence of the metabolite changes in the brain associated with cognitive impairment in anti-retroviral therapy naïve patients with HIV is unknown.

OBJECTIVE

To estimate the prevalence of the neurometabolites associated with cognitive impairment in antiretroviral therapy (ART) naïve patients with HIV.

METHODS

We conducted a cross-sectional study among ART naïve patients with HIV aged 18-50 years in a tertiary care center in India. Cognition was tested using the Post Graduate Institute battery of brain dysfunction across five domains; memory, attention-information processing, abstraction executive, complex perceptual, and simple motor skills. We assessed the total N-acetyl aspartyl (tNAA), creatine (tCr) and glutamate + glutamine (Glx) using 3T magnetic resonance spectroscopy. Cognitive impairment was defined as an impairment in ≥2 domains.

RESULTS

Among 43 patients eligible for this study, the median age was 32 years (IQR 29, 40) and 30% were women. Median CD4 count and viral load were 317 cells/μL (IQR 157, 456) and 9.3 copies/ μL (IQR 1.4, 38), respectively. Impairment in at least one cognitive domain was present in 32 patients (74.4%). Impairment in simple motor skills and memory was present in 46.5% and 44% of patients, respectively. Cognitive impairment, defined by impairment in ≥2 domains, was found in 22 (51.2%) patients. There was a trend towards higher concentration of tNAA (7.3 vs. 7.0 mmol/kg), tGlx (9.1 vs. 8.2 mmol/kg), and tCr (5.5 vs. 5.2 mmol/kg) in the frontal lobe of patients with cognitive impairment vs. without cognitive impairment but it did not reach statistical significance (p>0.05 for all). There was no difference in the concentration of these metabolites in the two groups in the basal ganglia.

CONCLUSION

There is a high prevalence of cognitive impairment in ART naïve patients with HIV. There is no difference in metabolites in patients with or without cognitive impairment. Further studies, with longitudinal follow-up are required to understand the underlying pathophysiological mechanisms.

Microbial biofilm: A matter of grave concern for human health and food industry

Pathogenic microorganisms have adapted different strategies during the course of time to invade host defense mechanisms and overcome the effect of potent antibiotics. The formation of biofilm on both biotic and abiotic surfaces by microorganisms is one such strategy to resist and survive even in presence of antibiotics and other adverse environmental conditions. Biofilm is a safe home of microorganisms embedded within self-produced extracellular polymeric substances comprising of polysaccharides, extracellular proteins, nucleic acid, and water. It is because of this adaptation strategy that pathogenic microorganisms are taking a heavy toll on the health and life of organisms. In this review, we discuss the colonization of pathogenic microorganisms on tissues and medically implanted devices in human beings. We also focus on food spoilage, disease outbreaks, biofilm-associated deaths, burden on economy, and other major concerns of biofilm-forming pathogenic microorganisms in food industries like dairy, poultry, ready-to-eat food, meat, and aquaculture.

Embryonal tumors with multilayered rosettes: A tertiary care centre experience

BACKGROUND

Embryonal tumors with multilayered rosettes (ETMR) is an extremely rare and highly aggressive tumor. It includes three distinct entities i.e, embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL) and medulloepithelioma (MEPL). Here, we present our institutional experience of seven ETMR cases treated over a period of five years.

MATERIALS AND METHODS

Patients' records from 2015 to 2019 were reviewed manually and electronically to retrieve the data. Clinicopathological and outcome details of ETMR cases were entered in a predesigned proforma.

RESULTS

A total of seven cases of ETMR were registered from 2015 to 2019 with a median age at presentation of four years (range 3-7 years). All patients underwent surgery. However, only three patients completed the planned adjuvant treatment, comprising of focal radiotherapy (RT) alone, craniospinal irradiation (CSI) alone and CSI followed by six cycles of chemotherapy in one patient each respectively. Two patients commenced CSI but deteriorated during RT and thereafter needed best supportive care. Two patients could not be started on any adjuvant treatment. Unfortunately, six patients succumbed to their disease within one year of their diagnosis. Only one patient who received both CSI and adjuvant chemotherapy is alive at 15 months of diagnosis.

CONCLUSION

ETMR is a rare and aggressive entity. Majority of the patients die within one year of the diagnosis despite multimodality treatment.

Plant genetic resources in India: management and utilization

Plant genetic resources (PGR) are the foundation of agriculture as well as food and nutritional security. The ICAR-NBPGR is the nodal institution at national level for management of PGR in India under the umbrella of Indian Council of Agricultural Research (ICAR), New Delhi. India being one of the gene-rich countries faces a unique challenge of protecting its natural heritage while evolving mutually beneficial strategies for germplasm exchange with other countries. The Bureaus activities include PGR exploration, collection, exchange, characterization, evaluation, conservation and documentation. It also has the responsibility to carry out quarantine of all imported PGR including transgenics meant for research purposes. The multifarious activities are carried out from ICAR-NBPGR headquarters and its 10 regional stations located in different agro-climatic zones of India. It has linkages with international organizations of the Consultative Group on International Agricultural Research (CGIAR) and national crop-based institutes to accomplish its mandated activities. NBPGR collects and acquires germplasm from various sources, conserves it in the Genebank, characterizes and evaluates it for different traits and provides ready material for breeders to develop varieties for farmers. ICAR-NBPGR encompasses the National Genebank Network and at present, the National Genebank conserves more than 0.40 million accessions. NBPGR works in service-mode for effective utilization of PGR in crop improvement programmes which depends mainly on its systematic characterization and evaluation, and identification of potentially useful germplasm. NBPGR is responsible for identifying trait-specific pre-adapted climate resilient genotypes, promising material with disease resistance and quality traits which the breeders use for various crop improvement programmes. The system has contributed immensely towards safeguarding the indigenous and introducing useful exotic PGR for enhancing the agricultural production. Presently, our focus is on characterization of ex situ conserved germplasm and detailed evaluation of prioritized crops for enhanced utilization; assessment of impact of on-farm conservation practices on genetic diversity; genome-wide association mapping for identification of novel genes and alleles for enhanced utilization of PGR; identification and deployment of germplasm/landraces using climate analog data; validation of trait-specific introduced germplasm for enhanced utilization. Key words: plant genetic resources; gene banks; wild relatives; biotic and abiotic stresses; marker-assisted selection.

Effect of prophylactic granulocyte-colony stimulating factor (G-CSF) on acute hematological toxicity in medulloblastoma patients during craniospinal irradiation (CSI)

OBJECTIVES

Haematological toxicity and treatment breaks are common during cranio-spinal irradiation (CSI) due to irradiation of large volume of bone marrow. We conducted this study to see the effect of prophylactic granulocyte colony stimulating factor (GCSF) in reducing treatment breaks.

PATIENTS AND METHODS

The study was conducted over a period of 15 months from August 2017 to November 2018. Histopathologically proven Medulloblastoma patients received prophylactic GCSF during CSI. Acute hematological toxicities and treatment breaks were noted and effect of age and pretreatment blood counts were analyzed by SPSS (Statistical Package for Social Sciences) version 23.

RESULTS

A total of 28 patients were included in the study. During CSI, hematological toxicity leading to treatment breaks was observed in 11 (39.3 %) patients, of which grade 3 and 2 toxicities were seen in ten and one patients respectively. Younger age (<10 years) at diagnosis was significantly associated with the development of hematological toxicity (p = 0.028, Chi-Square). No correlation was found with pre-treatment blood counts.

CONCLUSION

Prophylactic use of GCSF may be effective in preventing radiation induced hematological toxicity and treatment breaks.