Showing papers by "Rakesh K. Jain published in 2020"

A framework for advancing our understanding of cancer-associated fibroblasts

Abstract: Cancer-associated fibroblasts (CAFs) are a key component of the tumour microenvironment with diverse functions, including matrix deposition and remodelling, extensive reciprocal signalling interactions with cancer cells and crosstalk with infiltrating leukocytes. As such, they are a potential target for optimizing therapeutic strategies against cancer. However, many challenges are present in ongoing attempts to modulate CAFs for therapeutic benefit. These include limitations in our understanding of the origin of CAFs and heterogeneity in CAF function, with it being desirable to retain some antitumorigenic functions. On the basis of a meeting of experts in the field of CAF biology, we summarize in this Consensus Statement our current knowledge and present a framework for advancing our understanding of this critical cell type within the tumour microenvironment.

The blood–brain barrier and blood–tumour barrier in brain tumours and metastases

Abstract: For a blood-borne cancer therapeutic agent to be effective, it must cross the blood vessel wall to reach cancer cells in adequate quantities, and it must overcome the resistance conferred by the local microenvironment around cancer cells. The brain microenvironment can thwart the effectiveness of drugs against primary brain tumours as well as brain metastases. In this Review, we highlight the cellular and molecular components of the blood–brain barrier (BBB), a specialized neurovascular unit evolved to maintain brain homeostasis. Tumours are known to compromise the integrity of the BBB, resulting in a vasculature known as the blood–tumour barrier (BTB), which is highly heterogeneous and characterized by numerous distinct features, including non-uniform permeability and active efflux of molecules. We discuss the challenges posed by the BBB and BTB for drug delivery, how multiple cell types dictate BBB function and the role of the BTB in disease progression and treatment. Finally, we highlight emerging molecular, cellular and physical strategies to improve drug delivery across the BBB and BTB and discuss their impact on improving conventional as well as emerging treatments, such as immune checkpoint inhibitors and engineered T cells. A deeper understanding of the BBB and BTB through the application of single-cell sequencing and imaging techniques, and the development of biomarkers of BBB integrity along with systems biology approaches, should enable new personalized treatment strategies for primary brain malignancies and brain metastases. This Review discusses the structure and function of the blood–brain barrier (BBB) and how brain tumours and brain metastases compromise BBB integrity. It also discusses the challenges the BBB poses for cancer therapy and how these might be overcome.

Improving cancer immunotherapy using nanomedicines: progress, opportunities and challenges.

Abstract: Multiple nanotherapeutics have been approved for patients with cancer, but their effects on survival have been modest and, in some examples, less than those of other approved therapies. At the same time, the clinical successes achieved with immunotherapy have revolutionized the treatment of multiple advanced-stage malignancies. However, the majority of patients do not benefit from the currently available immunotherapies and many develop immune-related adverse events. By contrast, nanomedicines can reduce - but do not eliminate - the risk of certain life-threatening toxicities. Thus, the combination of these therapeutic classes is of intense research interest. The tumour microenvironment (TME) is a major cause of the failure of both nanomedicines and immunotherapies that not only limits delivery, but also can compromise efficacy, even when agents accumulate in the TME. Coincidentally, the same TME features that impair nanomedicine delivery can also cause immunosuppression. In this Perspective, we describe TME normalization strategies that have the potential to simultaneously promote the delivery of nanomedicines and reduce immunosuppression in the TME. Then, we discuss the potential of a combined nanomedicine-based TME normalization and immunotherapeutic strategy designed to overcome each step of the cancer-immunity cycle and propose a broadly applicable 'minimal combination' of therapies designed to increase the number of patients with cancer who are able to benefit from immunotherapy.

Physical traits of cancer.

Abstract: The role of the physical microenvironment in tumor development, progression, metastasis, and treatment is gaining appreciation. The emerging multidisciplinary field of the physical sciences of cancer is now embraced by engineers, physicists, cell biologists, developmental biologists, tumor biologists, and oncologists attempting to understand how physical parameters and processes affect cancer progression and treatment. Discoveries in this field are starting to be translated into new therapeutic strategies for cancer. In this Review, we propose four physical traits of tumors that contribute to tumor progression and treatment resistance: (i) elevated solid stresses (compression and tension), (ii) elevated interstitial fluid pressure, (iii) altered material properties (for example, increased tissue stiffness, which historically has been used to detect cancer by palpation), and (iv) altered physical microarchitecture. After defining these physical traits, we discuss their causes, consequences, and how they complement the biological hallmarks of cancer.

CCR2 inhibition reduces tumor myeloid cells and unmasks a checkpoint inhibitor effect to slow progression of resistant murine gliomas

Abstract: Immunotherapy directed at the PD-L1/PD-1 axis has produced treatment advances in various human cancers. Unfortunately, progress has not extended to glioblastoma (GBM), with phase III clinical trials assessing anti-PD-1 monotherapy failing to show efficacy in newly diagnosed and recurrent tumors. Myeloid-derived suppressor cells (MDSCs), a subset of immunosuppressive myeloid derived cells, are known to infiltrate the tumor microenvironment of GBM. Growing evidence suggests the CCL2–CCR2 axis is important for this process. This study evaluated the combination of PD-1 blockade and CCR2 inhibition in anti-PD-1–resistant gliomas. CCR2 deficiency unmasked an anti-PD-1 survival benefit in KR158 glioma-bearing mice. CD11b+/Ly6Chi/PD-L1+ MDSCs within established gliomas decreased with a concomitant increase in overall CCR2+ cells and MDSCs within bone marrow of CCR2-deficient mice. The CCR2 antagonist CCX872 increased median survival as a monotherapy in KR158 glioma-bearing animals and further increased median and overall survival when combined with anti-PD-1. Additionally, combination of CCX872 and anti-PD-1 prolonged median survival time in 005 GSC GBM-bearing mice. In both models, CCX872 decreased tumor associated MDSCs and increased these cells within the bone marrow. Examination of tumor-infiltrating lymphocytes revealed an elevated population, increased IFNγ expression, indicating enhanced cytolytic activity, as well as decreased expression of exhaustion markers in CD4+ and CD8+ T cells following combination treatment. These data establish that combining CCR2 and PD-1 blockade extends survival in clinically relevant murine glioma models and provides the basis on which to advance this combinatorial treatment toward early-phase human trials.

A metastasis map of human cancer cell lines.

Abstract: Most deaths from cancer are explained by metastasis, and yet large-scale metastasis research has been impractical owing to the complexity of in vivo models. Here we introduce an in vivo barcoding strategy that is capable of determining the metastatic potential of human cancer cell lines in mouse xenografts at scale. We validated the robustness, scalability and reproducibility of the method and applied it to 500 cell lines1,2 spanning 21 types of solid tumour. We created a first-generation metastasis map (MetMap) that reveals organ-specific patterns of metastasis, enabling these patterns to be associated with clinical and genomic features. We demonstrate the utility of MetMap by investigating the molecular basis of breast cancers capable of metastasizing to the brain—a principal cause of death in patients with this type of cancer. Breast cancers capable of metastasizing to the brain showed evidence of altered lipid metabolism. Perturbation of lipid metabolism in these cells curbed brain metastasis development, suggesting a therapeutic strategy to combat the disease and demonstrating the utility of MetMap as a resource to support metastasis research. A method in which pooled barcoded human cancer cell lines are injected into a mouse xenograft model enables simultaneous mapping of the metastatic potential of multiple cell lines, and shows that breast cancer cells that metastasize to the brain have altered lipid metabolism.

Combining microenvironment normalization strategies to improve cancer immunotherapy

Abstract: Advances in immunotherapy have revolutionized the treatment of multiple cancers. Unfortunately, tumors usually have impaired blood perfusion, which limits the delivery of therapeutics and cytotoxic immune cells to tumors and also results in hypoxia—a hallmark of the abnormal tumor microenvironment (TME)—that causes immunosuppression. We proposed that normalization of TME using antiangiogenic drugs and/or mechanotherapeutics can overcome these challenges. Recently, immunotherapy with checkpoint blockers was shown to effectively induce vascular normalization in some types of cancer. Although these therapeutic approaches have been used in combination in preclinical and clinical studies, their combined effects on TME are not fully understood. To identify strategies for improved immunotherapy, we have developed a mathematical framework that incorporates complex interactions among various types of cancer cells, immune cells, stroma, angiogenic molecules, and the vasculature. Model predictions were compared with the data from five previously reported experimental studies. We found that low doses of antiangiogenic treatment improve immunotherapy when the two treatments are administered sequentially, but that high doses are less efficacious because of excessive vessel pruning and hypoxia. Stroma normalization can further increase the efficacy of immunotherapy, and the benefit is additive when combined with vascular normalization. We conclude that vessel functionality dictates the efficacy of immunotherapy, and thus increased tumor perfusion should be investigated as a predictive biomarker of response to immunotherapy.

Limited Environmental Serine and Glycine Confer Brain Metastasis Sensitivity to PHGDH Inhibition.

Abstract: A hallmark of metastasis is the adaptation of tumor cells to new environments. Metabolic constraints imposed by the serine and glycine-limited brain environment restrict metastatic tumor growth. How brain metastases overcome these growth-prohibitive conditions is poorly understood. Here, we demonstrate that 3-phosphoglycerate dehydrogenase (PHGDH), which catalyzes the rate-limiting step of glucose-derived serine synthesis, is a major determinant of brain metastasis in multiple human cancer types and preclinical models. Enhanced serine synthesis proved important for nucleotide production and cell proliferation in highly aggressive brain metastatic cells. In vivo, genetic suppression and pharmacological inhibition of PHGDH attenuated brain metastasis, but not extracranial tumor growth, and improved overall survival in mice. These results reveal that extracellular amino acid availability determines serine synthesis pathway dependence, and suggests that PHGDH inhibitors may be useful in the treatment of brain metastasis.

Vessel co-option in glioblastoma: emerging insights and opportunities.

Abstract: Vessel co-option is the movement of cancer cells towards and along the pre-existing vasculature and is an alternative to angiogenesis to gain access to nutrients. Vessel co-option has been shown as a strategy employed by some glioblastoma (GBM) cells to invade further into the brain, leading to one of the greatest challenges in treating GBM. In GBM, vessel co-option may be an intrinsic feature or an acquired mechanism of resistance to anti-angiogenic treatment. Here, we describe the histological features and the dynamics visualized through intravital microscopy of vessel co-option in GBM, as well as the molecular players discovered until now. We also highlight key unanswered questions, as answering these is critical to improve understanding of GBM progression and for developing more effective approaches for GBM treatment.

Regorafenib combined with PD1 blockade increases CD8 T-cell infiltration by inducing CXCL10 expression in hepatocellular carcinoma.

Abstract: Background and purpose Combining inhibitors of vascular endothelial growth factor and the programmed cell death protein 1 (PD1) pathway has shown efficacy in multiple cancers, but the disease-specific and agent-specific mechanisms of benefit remain unclear. We examined the efficacy and defined the mechanisms of benefit when combining regorafenib (a multikinase antivascular endothelial growth factor receptor inhibitor) with PD1 blockade in murine hepatocellular carcinoma (HCC) models. Basic procedures We used orthotopic models of HCC in mice with liver damage to test the effects of regorafenib—dosed orally at 5, 10 or 20 mg/kg daily—combined with anti-PD1 antibodies (10 mg/kg intraperitoneally thrice weekly). We evaluated the effects of therapy on tumor vasculature and immune microenvironment using immunofluorescence, flow cytometry, RNA-sequencing, ELISA and pharmacokinetic/pharmacodynamic studies in mice and in tissue and blood samples from patients with cancer. Main findings Regorafenib/anti-PD1 combination therapy increased survival compared with regofarenib or anti-PD1 alone in a regorafenib dose-dependent manner. Combination therapy increased regorafenib uptake into the tumor tissues by normalizing the HCC vasculature and increasing CD8 T-cell infiltration and activation at an intermediate regorafenib dose. The efficacy of regorafenib/anti-PD1 therapy was compromised in mice lacking functional T cells (Rag1-deficient mice). Regorafenib treatment increased the transcription and protein expression of CXCL10—a ligand for CXCR3 expressed on tumor-infiltrating lymphocytes—in murine HCC and in blood of patients with HCC. Using Cxcr3-deficient mice, we demonstrate that CXCR3 mediated the increased intratumoral CD8 T-cell infiltration and the added survival benefit when regorafenib was combined with anti-PD1 therapy. Principal conclusions Judicious regorafenib/anti-PD1 combination therapy can inhibit tumor growth and increase survival by normalizing tumor vasculature and increasing intratumoral CXCR3+CD8 T-cell infiltration through elevated CXCL10 expression in HCC cells.

Comparing Machine Learning Algorithms for Predicting ICU Admission and Mortality in COVID-19

Abstract: As predicting the trajectory of COVID-19 disease is challenging, machine learning models could assist physicians determine high-risk individuals. This study compares the performance of 18 machine learning algorithms for predicting ICU admission and mortality among COVID-19 patients. Using COVID-19 patient data from the Mass General Brigham (MGB) healthcare database, we developed and internally validated models using patients presenting to Emergency Department (ED) between March-April 2020 (n = 1144) and externally validated them using those individuals who encountered ED between May-August 2020 (n = 334). We show that ensemble-based models perform better than other model types at predicting both 5-day ICU admission and 28-day mortality from COVID-19. CRP, LDH, and procalcitonin levels were important for ICU admission models whereas eGFR

Bevacizumab Reduces Permeability and Concurrent Temozolomide Delivery in a Subset of Patients with Recurrent Glioblastoma.

Abstract: Purpose: Targeting tumor blood vessels is an attractive therapy in glioblastoma (GBM), but the mechanism of action of these agents and how they modulate delivery of concomitant chemotherapy are not clear in humans. We sought to elucidate how bevacizumab modulates tumor vasculature and the impact those vascular changes have on drug delivery in patients with recurrent GBM. Experimental Design: Temozolomide was labeled with [11C], and serial PET-MRI scans were performed in patients with recurrent GBM treated with bevacizumab and daily temozolomide. PET-MRI scans were performed prior to the first bevacizumab dose, 1 day after the first dose, and prior to the third dose of bevacizumab. We calculated tumor volume, vascular permeability (Ktrans), perfusion (cerebral blood flow), and the standardized uptake values (SUV) of [11C] temozolomide within the tumor. Results: Twelve patients were enrolled, resulting in 23 evaluable scans. Within the entire contrast-enhancing tumor volume, both temozolomide uptake and vascular permeability decreased after initiation of bevacizumab in most patients, whereas change in perfusion was more variable. In subregions of the tumor where permeability was low and the blood–brain barrier not compromised, increased perfusion correlated with increased temozolomide uptake. Conclusions: Bevacizumab led to a decrease in permeability and concomitant delivery of temozolomide. However, in subregions of the tumor where permeability was low, increased perfusion improved delivery of temozolomide, suggesting that perfusion may modulate the delivery of chemotherapy in certain settings. These results support exploring whether lower doses of bevacizumab improve perfusion and concomitant drug delivery.

Brain Metastasis Cell Lines Panel: A Public Resource of Organotropic Cell Lines.

Abstract: Spread of cancer to the brain remains an unmet clinical need in spite of the increasing number of cases among patients with lung, breast cancer, and melanoma most notably. Although research on brain metastasis was considered a minor aspect in the past due to its untreatable nature and invariable lethality, nowadays, limited but encouraging examples have questioned this statement, making it more attractive for basic and clinical researchers. Evidences of its own biological identity (i.e., specific microenvironment) and particular therapeutic requirements (i.e., presence of blood-brain barrier, blood-tumor barrier, molecular differences with the primary tumor) are thought to be critical aspects that must be functionally exploited using preclinical models. We present the coordinated effort of 19 laboratories to compile comprehensive information related to brain metastasis experimental models. Each laboratory has provided details on the cancer cell lines they have generated or characterized as being capable of forming metastatic colonies in the brain, as well as principle methodologies of brain metastasis research. The Brain Metastasis Cell Lines Panel (BrMPanel) represents the first of its class and includes information about the cell line, how tropism to the brain was established, and the behavior of each model in vivo. These and other aspects described are intended to assist investigators in choosing the most suitable cell line for research on brain metastasis. The main goal of this effort is to facilitate research on this unmet clinical need, to improve models through a collaborative environment, and to promote the exchange of information on these valuable resources.

Antibody-mediated delivery of viral epitopes to tumors harnesses CMV-specific T cells for cancer therapy

Abstract: Several cancer immunotherapy approaches, such as immune checkpoint blockade and adoptive T-cell therapy, boost T-cell activity against the tumor, but these strategies are not effective in the absence of T cells specific for displayed tumor antigens. Here we outline an immunotherapy in which endogenous T cells specific for a noncancer antigen are retargeted to attack tumors. The approach relies on the use of antibody-peptide epitope conjugates (APECs) to deliver suitable antigens to the tumor surface for presention by HLA-I. To retarget cytomegalovirus (CMV)-specific CD8+ T cells against tumors, we used APECs containing CMV-derived epitopes conjugated to tumor-targeting antibodies via metalloprotease-sensitive linkers. These APECs redirect pre-existing CMV immunity against tumor cells in vitro and in mouse cancer models. In vitro, APECs activated specifically CMV-reactive effector T cells whereas a bispecific T-cell engager activated both effector and regulatory T cells. Our approach may provide an effective alternative in cancers that are not amenable to checkpoint inhibitors or other immunotherapies.

Non-invasive monitoring of chronic liver disease via near-infrared and shortwave-infrared imaging of endogenous lipofuscin.

Abstract: Monitoring the progression of non-alcoholic fatty liver disease is hindered by a lack of suitable non-invasive imaging methods. Here, we show that the endogenous pigment lipofuscin displays strong near-infrared and shortwave-infrared fluorescence when excited at 808 nm, enabling label-free imaging of liver injury in mice and the discrimination of pathological processes from normal liver processes with high specificity and sensitivity. We also show that the near-infrared and shortwave-infrared fluorescence of lipofuscin can be used to monitor the progression and regression of liver necroinflammation and fibrosis in mouse models of non-alcoholic fatty liver disease and advanced fibrosis, as well as to detect non-alcoholic steatohepatitis and cirrhosis in biopsied samples of human liver tissue. Label-free imaging of the endogenous pigment lipofuscin at near-infrared and shortwave-infrared wavelengths enables the longitudinal monitoring of liver injury in mice and in biopsied human livers.

A bilateral tumor model identifies transcriptional programs associated with patient response to immune checkpoint blockade.

Abstract: Immune checkpoint blockade (ICB) is efficacious in many diverse cancer types, but not all patients respond. It is important to understand the mechanisms driving resistance to these treatments and to identify predictive biomarkers of response to provide best treatment options for all patients. Here we introduce a resection and response-assessment approach for studying the tumor microenvironment before or shortly after treatment initiation to identify predictive biomarkers differentiating responders from nonresponders. Our approach builds on a bilateral tumor implantation technique in a murine metastatic breast cancer model (E0771) coupled with anti-PD-1 therapy. Using our model, we show that tumors from mice responding to ICB therapy had significantly higher CD8+ T cells and fewer Gr1+CD11b+ myeloid-derived suppressor cells (MDSCs) at early time points following therapy initiation. RNA sequencing on the intratumoral CD8+ T cells identified the presence of T cell exhaustion pathways in nonresponding tumors and T cell activation in responding tumors. Strikingly, we showed that our derived response and resistance signatures significantly segregate patients by survival and associate with patient response to ICB. Furthermore, we identified decreased expression of CXCR3 in nonresponding mice and showed that tumors grown in Cxcr3−/− mice had an elevated resistance rate to anti-PD-1 treatment. Our findings suggest that the resection and response tumor model can be used to identify response and resistance biomarkers to ICB therapy and guide the use of combination therapy to further boost the antitumor efficacy of ICB.

Genetics of Thrips palmi (Thysanoptera: Thripidae)

Abstract: Melon thrips (Thrips palmi) is the principal insect pest of vegetable and ornamental plants worldwide. In addition to inflicting feeding injuries on host plants, they act as vectors of economically damaging tospoviruses. Application of insecticides and host plant resistance has proven largely ineffective in the management of T. palmi. However, increasingly, genetic knowledge is being successfully utilized to manage insect pests. A number of recent studies have enriched the genetic database of T. palmi. In this review, we report on genetics of T. palmi for species identification and to study its populations structure. For example, a DNA polymorphism analysis of global T. palmi populations has revealed the existence of 29 haplotypes. The T. palmi population can be divided into three lineages based on phylogenetic analysis. A high maximum intraspecific distance is indicative of cryptic species within T. palmi populations. Regarding climate adaptability, the upregulation of trehalose biosynthesis genes, and genes encoding several heat-shock proteins is expected to enable T. palmi thermal adaptation to both cold and hot conditions. Genetics of T. palmi has shown that resistance to conventional insecticides like cypermethrin appears to be linked to mutations in the sodium channel. On the other hand, resistance to imidacloprid appears to be a result of cytochrome P450-mediated detoxification. T. palmi genes potentially involved in tospovirus transmission are also reviewed and new molecular tools for genetic study presented. Molecular modeling and docking analyses of groundnut bud necrosis virus glycoprotein demonstrated protein–protein interactions with T. palmi vacuolar ATP synthase E subunit, cathepsin, clathrin, adaptor protein 2, and enolase. Overall, a better knowledge of T. palmi genes will assist elucidation of thrips identification, means of adaptation in diverse ecological niches, mechanisms of insecticide resistance, and transmission of plant viruses. This data will be an invaluable tool for integrated thrips management.

A phase II study of cabozantinib alone or in combination with trastuzumab in breast cancer patients with brain metastases.

Abstract: To analyze the efficacy and tolerability of cabozantinib—a small molecule inhibitor of MET and VEGFR2—alone or with trastuzumab in patients with breast cancer brain metastases (BCBM). This single-arm phase II study enrolled patients with new or progressive measurable BCBM into 3 cohorts: Cohort 1 (HER2-positive), Cohort 2 (hormone receptor-positive/HER2-negative), and Cohort 3 (triple-negative). Patients received cabozantinib 60-mg daily on a 21-day cycle. Cohort 1 added trastuzumab every 3 weeks and had a primary objective of central nervous system (CNS) objective response rate (ORR) by RECIST 1.1. Secondary objectives for all cohorts were progression-free survival, overall survival, toxicity, and changes in vascular parameters and circulating biomarkers. Cohorts 2 and 3 also had CNS ORR as a secondary objective. Thirty-six BCBM patients enrolled (cohort 1, n = 21; cohort 2, n = 7; cohort 3, n = 8), with a median age of 50. Patients had a median of 3 prior lines for metastatic disease (range 1–9). Treatments prior to enrollment included craniotomy (n = 4), whole brain radiation (n = 24) and stereotactic radiosurgery (n = 11). CNS ORR was 5% in cohort 1, 14% in cohort 2, and 0% in cohort 3. Most common grade 3/4 adverse events included elevations in lipase (11%), AST (8%), ALT (6%), hyponatremia (8%), and hypertension (6%). Cabozantinib increased plasma concentrations of CA-IX, soluble (s)MET, PlGF, sTIE-2, VEGF, and VEGF-D, and decreased sVEGFR2 and TNF-α and total tumor blood volume. Cabozantinib had insufficient activity in heavily pretreated BCBM patients. Biomarker analysis showed that cabozantinib had antiangiogenic activity and increased tissue hypoxia. Clinicaltrial.gov registration: NCT02260531.

In vivo compression and imaging in mouse brain to measure the effects of solid stress.

Abstract: We recently developed an in vivo compression device that simulates the solid mechanical forces exerted by a growing tumor on the surrounding brain tissue and delineates the physical versus biological effects of a tumor. This device, to our knowledge the first of its kind, can recapitulate the compressive forces on the cerebellar cortex from primary (e.g., glioblastoma) and metastatic (e.g., breast cancer) tumors, as well as on the cerebellum from tumors such as medulloblastoma and ependymoma. We adapted standard transparent cranial windows normally used for intravital imaging studies in mice to include a turnable screw for controlled compression (acute or chronic) and decompression of the cerebral cortex. The device enables longitudinal imaging of the compressed brain tissue over several weeks or months as the screw is progressively extended against the brain tissue to recapitulate tumor growth-induced solid stress. The cranial window can be simply installed on the mouse skull according to previously established methods, and the screw mechanism can be readily manufactured in-house. The total time for construction and implantation of the in vivo compressive cranial window is <1 h (per mouse). This technique can also be used to study a variety of other diseases or disorders that present with abnormal solid masses in the brain, including cysts and benign growths.

Using opportunistic screening with abdominal CT to identify osteoporosis and osteopenia in patients with diabetes.

Abstract: Opportunistic osteoporosis screening involves measuring the attenuation of L1 vertebrae on abdominal computed tomography (CT), which correlates with DXA T-score. We found that this approach is useful for detecting low bone mass in patients with diabetes and propose L1 attenuation ≤ 135 Hounsfield units (HU) as a threshold for which DXA should be strongly considered. Attenuation of the L1 vertebrae on computer tomography (CT) images done for other reasons (“Opportunistic Osteoporosis Screening”) has been found to correlate well with DXA-derived T-score. However, the method and the thresholds have never been tested specifically in those with diabetes mellitus (DM), in whom the fracture risk is greater than explained by BMD. In a retrospective study of subjects with DM who had both abdominal CT and DXA within 6 months of each other, we compared L1 attenuation and DXA T-score to define the sensitivity and specificity of thresholds previously established in the general population. There were 313 subjects among whom 18 (5.8%) had prior major osteoporotic fracture (MOF). Subjects with MOF had lower T-scores (− 2.3 ± 1.4 vs. − 0.9 ± 1.4, p < 0.001) and L1 attenuation (104 HU ± 46 vs. 149 HU ± 47, p < 0.001) than non-fracture subjects. L1 attenuation ≤ 160 HU was 91% sensitive for osteoporosis, while ≤ 110 HU was 80% specific. For a higher T-score of ≤ − 1.5, L1 attenuation ≤ 135 HU showed balanced sensitivity and specificity (65% and 69%, respectively). Opportunistic osteoporosis screening with abdominal CT is useful in determining the need for DXA screening in subjects with diabetes. We propose L1 attenuation ≤ 135 HU as a reasonable threshold for detecting the T-score of ≤ − 1.5, which is likely associated with increased fragility in DM.

Present Status and Future Management Strategies for Sugarcane Yellow Leaf Virus: A Major Constraint to the Global Sugarcane Production

Abstract: Sugarcane yellow leaf virus (SCYLV) is a distinct member of the Polerovirus genus of the Luteoviridae family. SCYLV is the major limitation to sugarcane production worldwide and presently occurring in most of the sugarcane growing countries. SCYLV having high genetic diversity within the species and presently ten genotypes are known to occur based on the complete genome sequence information. SCYLV is present in almost all the states of India where sugarcane is grown. Virion comprises of 180 coat protein units and are 24-29 nm in diameter. The genome of SCYLV is a monopartite and comprised of single-stranded (ss) positive-sense (+) linear RNA of about 6 kb in size. Virus genome consists of six open reading frames (ORFs) that are expressed by sub-genomic RNAs. The SCYLV is phloem-limited and transmitted by sugarcane aphid Melanaphis sacchari in a circulative and non-propagative manner. The other aphid species namely, Ceratovacuna lanigera, Rhopalosiphum rufiabdominalis, and R. maidis also been reported to transmit the virus. The virus is not transmitted mechanically, therefore, its transmission by M. sacchari has been studied in different countries. SCYLV has a limited natural host range and mainly infect sugarcane (Sachharum hybrid), grain sorghum (Sorghum bicolor), and Columbus grass (Sorghum almum). Recent insights in the protein-protein interactions of Polerovirus through protein interaction reporter (PIR) technology enable us to understand viral encoded proteins during virus replication, assembly, plant defence mechanism, short and long-distance travel of the virus. This review presents the recent understandings on virus biology, diagnosis, genetic diversity, virus-vector and host-virus interactions and conventional and next generation management approaches.

In silico dynamics of COVID-19 phenotypes for optimizing clinical management

Abstract: Understanding the underlying mechanisms of COVID-19 progression and the impact of various pharmaceutical interventions is crucial for the clinical management of the disease We developed a comprehensive mathematical framework based on the known mechanisms of the SARS-CoV-2 virus infection, incorporating the renin-angiotensin system and ACE2, which the virus exploits for cellular entry, key elements of the innate and adaptive immune responses, the role of inflammatory cytokines and the coagulation cascade for thrombus formation The model predicts the evolution of viral load, immune cells, cytokines, thrombosis, and oxygen saturation based on patient baseline condition and the presence of co-morbidities Model predictions were validated with clinical data from healthy people and COVID-19 patients, and the results were used to gain insight into identified risk factors of disease progression including older age, co-morbidities such as obesity, diabetes, and hypertension, and dysregulated immune response (1,2) We then simulated treatment with various drug classes to identify optimal therapeutic protocols We found that the outcome of any treatment depends on the sustained response rate of activated CD8 (+) T cells and sufficient control of the innate immune response Furthermore, the best treatment -or combination of treatments - depends on the pre-infection health status of the patient Our mathematical framework provides important insight into SARS-CoV-2 pathogenesis and could be used as the basis for personalized, optimal management of COVID-19

NAD+-mediated rescue of prenatal forebrain angiogenesis restores postnatal behavior.

Abstract: Intrinsic defects within blood vessels from the earliest developmental time points can directly contribute to psychiatric disease origin. Here, we show that nicotinamide adenine dinucleotide (NAD+), administered during a critical window of prenatal development, in a mouse model with dysfunctional endothelial γ-aminobutyric acid type A (GABAA) receptors (Gabrb3 endothelial cell knockout mice), results in a synergistic repair of impaired angiogenesis and normalization of brain development, thus preventing the acquisition of abnormal behavioral symptoms. The prenatal NAD+ treatment stimulated extensive cellular and molecular changes in endothelial cells and restored blood vessel formation, GABAergic neuronal development, and forebrain morphology by recruiting an alternate pathway for cellular repair, via previously unknown transcriptional mechanisms and purinergic receptor signaling. Our findings illustrate a novel and powerful role for NAD+ in sculpting prenatal brain development that has profound implications for rescuing brain blood flow in a permanent and irreversible manner, with long-lasting consequences for mental health outcome.

A multiplex PCR assay for rapid identification of major tospovirus vectors reported in India

Abstract: To date, four thrips vectors have been reported to transmit five different tospoviruses in India. Their identification at an early stage is crucial in formulating appropriate pest management strategies. Since morphometric key-based thrips identification based on the adult stage is time-consuming, there is a need to develop diagnostic tools which are rapid, accurate, and independent of developmental stages. Here, we report a multiplex PCR assay to identify four major thrips vectors viz. Thrips palmi, T. tabaci, Scirtothrips dorsalis, and Frankliniella schultzei present in India. Cytochrome oxidase subunit III and internal transcribed spacer region 2 were utilized to design species-specific primers. Of 38 pairs of primers tested, primer pairs AG35F-AG36R, AG47F-AG48R, AG87F-AG88R, and AG79F-AG80R amplified 568 bp, 713 bp, 388 bp, and 200 bp products from the DNA templates of T. palmi, S. dorsalis, T. tabaci, and F. schultzei, respectively at same PCR conditions. The specificity of the primer pairs was validated with a large number of known specimens and no cross-reactivity was observed with other thrips species. The multiplex PCR assay with a cocktail of all the four primer pairs detected four thrips vectors efficiently and could discriminate all of them concurrently in a single reaction. The multiplex PCR reported in this study could identify the major thrips vectors reported in India. The assay will be useful in ascertaining distribution profile of major thrips vectors, disease epidemiology, screening large samples, and quarantine.

Vascular dysfunction promotes regional hypoxia after bevacizumab therapy in recurrent glioblastoma patients

Abstract: Background Hypoxia is a driver of treatment resistance in glioblastoma. Antiangiogenic agents may transiently normalize blood vessels and decrease hypoxia before excessive pruning of vessels increases hypoxia. The time window of normalization is dose and time dependent. We sought to determine how VEGF blockade with bevacizumab modulates tumor vasculature and the impact that those vascular changes have on hypoxia in recurrent glioblastoma patients. Methods We measured tumor volume, vascular permeability (Ktrans), perfusion parameters (cerebral blood flow/volume, vessel caliber, and mean transit time), and regions of hypoxia in patients with recurrent glioblastoma before and after treatment with bevacizumab alone or with lomustine using [18F]FMISO PET-MRI. We also examined serial changes in plasma biomarkers of angiogenesis and inflammation. Results Eleven patients were studied. The magnitude of global tumor hypoxia was variable across these 11 patients prior to treatment and it did not significantly change after bevacizumab. The hypoxic regions had an inefficient vasculature characterized by elevated cerebral blood flow/volume and increased vessel caliber. In a subset of patients, there were tumor subregions with decreased mean transit times and a decrease in hypoxia, suggesting heterogeneous improvement in vascular efficiency. Bevacizumab significantly changed known pharmacodynamic biomarkers such as plasma VEGF and PlGF. Conclusions The vascular signature in hypoxic tumor regions indicates a disorganized vasculature which, in most tumors, does not significantly change after bevacizumab treatment. While some tumor regions showed improved vascular efficiency following treatment, bevacizumab did not globally alter hypoxia or normalize tumor vasculature in glioblastoma.

Tumor Microenvironment: Vascular and Extravascular Compartment

Abstract: A solid tumor is an organ composed of neoplastic cells and host stromal cells nourished by the vasculature made of endothelial cells—all embedded in an extracellular matrix. The interactions among these cells, their surrounding matrix, and their local microenvironment control the expression of various genes. The products encoded by these genes, in turn, control the pathophysiologic characteristics of the tumor. Tumor pathophysiology governs not only tumor growth, invasion, and metastasis but also the response to various therapies. This chapter discusses various pathophysiologic parameters that characterize the vascular and extravascular compartments of a tumor and the mechanisms governing the formation and function of these compartments.

An observation on the embryonic development in Thrips palmi (Thysanoptera: Thripidae) eggs obtained by an artificial oviposition setup

Abstract: Thrips palmi is an important insect pest of vegetables and ornamental crops worldwide. Besides direct damage caused by feeding, it transmits several tospoviruses in a persistent-propagative manner. Eggs of T. palmi are microscopic and embedded within plant tissue by the sharp ovipositor of adult female. In the present study, an artificial oviposition setup has been standardized for T. palmi. Eggs of T. palmi were harvested in sterile water between two thin membranes. The developmental stages of T. palmi embryo were studied starting from oviposition up to hatching by inverted and confocal reflection microscopy. Energids were homogeneously distributed at an early stage of development. The anterior end of the egg curved with a constriction post 38 h. Initiation of tissue organization, mouthparts, appendages, compound eyes were observed at different time points. Appendages were well developed and segmentation was prominent post 70 h. The embryo was completely developed at around 80 h and hatched by 86 h post oviposition at 28 °C temperature. The study first time reports the embryonic development of T. palmi that would be helpful in detailed investigations of thrips developmental biology and evolution.

Multiple simultaneous fractures are associated with higher all-cause mortality: results from a province-wide fracture liaison service

Abstract: Mortality rates in our fracture liaison service ranged from 2.7% at year 1 to 14.8% at year 5 post-screening. Presentation with multiple simultaneous fractures at screening was associated with higher risk of death. This finding indicates the need for increased focus on this high-risk group. To examine all-cause mortality rates in a provincial fracture liaison service (FLS) and the association between the index fracture type, particularly multiple simultaneous fractures, and the risk of death at follow-up. This cohort study includes fragility fracture patients aged 50+, enrolled in a provincial FLS in Ontario, Canada, between 2007 and 2010. All-cause mortality was assessed using administrative data. Multivariable Cox proportional hazards model was used to examine the risk of death 5 years after screening. Crude mortality rates for 6543 fragility fracture patients were 2.7% at year 1, 5.6% at year 2, and 14.8% at year 5 after screening. After adjusting for age and sex, and relative to distal radius fracture, patients with multiple (simultaneous) fractures at screening had a higher risk of dying (HR = 1.8, 95%CI 1.3–2.4), followed by those with a hip fracture (HR = 1.5, 95%CI 1.3–1.8), a proximal humerus fracture (HR = 1.4, 95%CI 1.2–1.7), and other single fractures (HR = 1.4, 95%CI 1.1–1.7). Having an index ankle fracture was not associated with the risk of death over a distal radius fracture. As compared to the 50–65 age group, patients 66 years and older had a higher risk of death (for 66–70 age group: HR = 2.5, 95%CI 1.9–3.3; for 71–80: HR = 4.3, 95%CI 3.5–5.4; and for 81+: HR = 10.6, 95%CI 8.7–13.0). Females had a lower risk of death (HR = 0.5, 95%CI 0.5–0.6) than males. Presenting with multiple fractures was an indicator of higher risk of death relative to a distal radius fracture. This finding indicates the need for increased focus on this high-risk group.