Kyasanur forest disease: a state-of-the-art review

Kyasanur forest disease (KFD) virus is a flavivirus that can be transmitted to humans from monkeys or other mammals through hard ticks (Haemaphysalis spinigera). The disease is endemic to 16 districts in 5 states of Southern India and is reported in the dry season, most commonly in humans travelling to the forests in these areas. The aim of this systematic review is to raise awareness of the clinical and laboratory manifestation of KFD among physicians and travel medicine practitioners. A total of 153 articles were screened of which 16 articles that met the inclusion and exclusion criteria were included for qualitative analysis. KFD is an acute haemorrhagic fever with a biphasic component in some individuals. The second phase is usually marked by neurological symptoms. Leucopoenia, thrombocytopenia and elevated transaminases are the hallmarks of the first phase of KFD. The diagnostic modality of choice in the first few days of illness is polymerase chain reaction assay, whereas serology is used in the late phase. In the absence of a specific antiviral treatment, the clinical management of patients is limited to supportive care. Avoidance of exposure and vaccination is recommended to prevent this infection.

FDA Approval Summary: Pertuzumab, Trastuzumab, and Hyaluronidase-zzxf Injection for Subcutaneous Use in Patients with HER2-positive Breast Cancer

On June 29, 2020, the FDA approved pertuzumab, trastuzumab, and hyaluronidase-zzxf subcutaneous injection (Phesgo) for the treatment of patients with HER2-positive early-stage and metastatic breast cancer. Patients should be selected for therapy based on an FDA-approved companion diagnostic test. Approval was primarily based on the FeDeriCa trial, a randomized, open-label, multicenter comparability study of pertuzumab, trastuzumab, and hyaluronidase-zzxf subcutaneous injection compared with intravenous pertuzumab and intravenous trastuzumab administered in the neoadjuvant and adjuvant settings with chemotherapy for the treatment of patients with early breast cancer. The pharmacokinetic endpoints were, first, to demonstrate that the exposure of subcutaneous pertuzumab was not inferior to that of intravenous pertuzumab, and then to demonstrate that the exposure of subcutaneous trastuzumab was not inferior to that of intravenous trastuzumab. The primary endpoints were met with the observed lower limit of the two-sided 90% confidence intervals above the prespecified noninferiority margins. The most common adverse reactions were alopecia, nausea, diarrhea, anemia, and asthenia. The totality of the evidence demonstrated comparability of the subcutaneous product to intravenous, allowing for extrapolation and approval of all breast cancer indications for which intravenous trastuzumab and pertuzumab are approved.

Economic costs of Fusarium Head Blight, scab and deoxynivalenol

Fusarium Head Blight (FHB) has led to major economic costs for wheat and barley producers. Grain products and feed grain contaminated with deoxynivalenol (DON) (commonly known as vomitoxin) are subject to Food and Drug Administration advisory limits and as a result end-users place restrictions on their use. This has led to steep price discounts, as well as higher risks for producers and grain merchandisers. Varietal research has led to development of varieties that are resistant or moderately resistant to FHB. Studies indicate combinations of genetic resistance, fungicides and some management practices (combine settings, tillage practices, etc.) can be used to decrease economic costs due to FHB. The purpose of this study was to estimate the economic costs of scab. To do so we developed several economic models, analysed extensive data and conducted surveys of wheat flour millers, barley maltsters, and grain handlers. A detailed assessment of costs indicates the most important costs accrued by the wheat and barley industries were the risk premium paid to induce adoption of DON reducing technologies and the value of yield forgone. These were followed by the direct costs of fungicide, added shipping costs, testing and segregation and discounts.

The critical size of focal articular cartilage defects is associated with strains in the collagen fibers

The size of full-thickness focal cartilage defect is accepted to be predictive of its fate, but at which size threshold treatment is required is unclear. Clarification of the mechanism behind this threshold effect will help determining when treatment is required. The objective was to investigate the effect of defect size on strains in the collagen fibers and the non-fibrillar matrix of surrounding cartilage. These strains may indicate matrix disruption. Tissue deformation into the defect was expected, stretching adjacent superficial collagen fibers, while an osteochondral implant was expected to prevent these deformations. Finite element simulations of cartilage/cartilage contact for intact, 0.5 to 8mm wide defects and 8mm implant cases were performed. Impact, a load increase to 2MPa in 1ms, and creep loading, a constant load of 0.5MPa for 900s, scenarios were simulated. A composition-based material model for articular cartilage was employed. Impact loading caused low strain levels for all models. Creep loading increased deviatoric strains and collagen strains in the surrounding cartilage. Deviatoric strains increased gradually with defect size, but the surface area at which collagen fiber strains exceeded failure thresholds, abruptly increased for small increases of defect size. This was caused by a narrow distribution of collagen fiber strains resulting from the non-linear stiffness of the fibers. We postulate this might be the mechanism behind the existence of a critical defect size. Filling of the defect with an implant reduced deviatoric and collagen fiber strains towards values for intact cartilage.

International Working Group consensus response evaluation criteria in lymphoma (RECIL 2017)

In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new "basket" clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography or bidimensional tumor measurements on computerized tomography scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single-dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47 828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

Normalisation of hypoxaemia following successful percutaneous closure of a bidirectional shunting secundum atrial septal defect without pulmonary hypertension in a patient with severe non-ischaemic cardiomyopathy and refractory ventricular tachycardia

Atrial septal defects (ASD) are an uncommon cause of dyspnoea. A high index of suspicion is required, and further investigation should be prompted in patients with unexplained hypoxaemia, particularly those with pulmonary hypertension. Hypoxic ASD without pulmonary hypertension are rare, and only a handful of cases have been published. We present a middle-aged man with progressive dyspnoea with a successfully closed ASD without pulmonary hypertension caused by elevated right ventricular pressures secondary to an idiopathic cardiomyopathy.

Relative contribution of articular cartilage's constitutive components to load support depending on strain rate

Cartilage is considered a biphasic material in which the solid is composed of proteoglycans and collagen. In biphasic tissue, the hydraulic pressure is believed to bear most of the load under higher strain rates and its dissipation due to fluid flow determines creep and relaxation behavior. In equilibrium, hydraulic pressure is zero and load bearing is transferred to the solid matrix. The viscoelasticity of the collagen network also contributes to its time-dependent behavior, and the osmotic pressure to load bearing in equilibrium. The aim of the present study was to determine the relative contributions of hydraulic pressure, viscoelastic collagen stress, solid matrix stiffness and osmotic pressure to load carriage in cartilage under transient and equilibrium conditions. Unconfined compression experiments were simulated using a fibril-reinforced poroviscoelastic model of articular cartilage, including water, fibrillar viscoelastic collagen and non-fibrillar charged glycosaminoglycans. The relative contributions of hydraulic and osmotic pressures and stresses in the fibrillar and non-fibrillar network were evaluated in the superficial, middle and deep zone of cartilage under five different strain rates and after relaxation. Initially upon loading, the hydraulic pressure carried most of the load in all three zones. The osmotic swelling pressure carried most of the equilibrium load. In the surface zone, where the fibers were loaded in tension, the collagen network carried 20 % of the load for all strain rates. The importance of these fibers was illustrated by artificially modifying the fiber architecture, which reduced the overall stiffness of cartilage in all conditions. In conclusion, although hydraulic pressure dominates the transient behavior during cartilage loading, due to its viscoelastic nature the superficial zone collagen fibers carry a substantial part of the load under transient conditions. This becomes increasingly important with higher strain rates. The interesting and striking new insight from this study suggests that under equilibrium conditions, the swelling pressure generated by the combination of proteoglycans and collagen reinforcement accounts cartilage stiffness for more than 90 % of the loads carried by articular cartilage. This finding is different from the common thought that load is transferred from fluid to solid and is carried by the aggregate modulus of the solid. Rather, it is transformed from hydraulic to osmotic swelling pressure. These results show the importance of considering both (viscoelastic) collagen fibers as well as swelling pressure in studies of the (transient) mechanical behavior of cartilage.

Mutant KRAS Conversion of Conventional T Cells into Regulatory T Cells

Constitutive activation of the KRAS oncogene in human malignancies is associated with aggressive tumor growth and poor prognosis. Similar to other oncogenes, KRAS acts in a cell-intrinsic manner to affect tumor growth or survival. However, we describe here a different, cell-extrinsic mechanism through which mutant KRAS contributes to tumor development. Tumor cells carrying mutated KRAS induced highly suppressive T cells, and silencing KRAS reversed this effect. Overexpression of the mutant KRAS(G12V)gene in wild-type KRAS tumor cells led to regulatory T-cell (Treg) induction. We also demonstrate that mutant KRAS induces the secretion of IL10 and transforming growth factor-β1 (both required for Treg induction) by tumor cells through the activation of the MEK-ERK-AP1 pathway. Finally, we report that inhibition of KRAS reduces the infiltration of Tregs in KRAS-driven lung tumorigenesis even before tumor formation. This cell-extrinsic mechanism allows tumor cells harboring a mutant KRAS oncogene to escape immune recognition. Thus, an oncogene can promote tumor progression independent of its transforming activity by increasing the number and function of Tregs. This has a significant clinical potential, in which targeting KRAS and its downstream signaling pathways could be used as powerful immune modulators in cancer immunotherapy.

Control of PD-L1 Expression by Oncogenic Activation of the AKT-mTOR Pathway in Non-Small Cell Lung Cancer

Alterations in EGFR, KRAS, and ALK are oncogenic drivers in lung cancer, but how oncogenic signaling influences immunity in the tumor microenvironment is just beginning to be understood. Immunosuppression likely contributes to lung cancer, because drugs that inhibit immune checkpoints like PD-1 and PD-L1 have clinical benefit. Here, we show that activation of the AKT-mTOR pathway tightly regulates PD-L1 expression in vitro and in vivo. Both oncogenic and IFNγ-mediated induction of PD-L1 was dependent on mTOR. In human lung adenocarcinomas and squamous cell carcinomas, membranous expression of PD-L1 was significantly associated with mTOR activation. These data suggest that oncogenic activation of the AKT-mTOR pathway promotes immune escape by driving expression of PD-L1, which was confirmed in syngeneic and genetically engineered mouse models of lung cancer where an mTOR inhibitor combined with a PD-1 antibody decreased tumor growth, increased tumor-infiltrating T cells, and decreased regulatory T cells.

A computational spinal motion segment model incorporating a matrix composition-based model of the intervertebral disc

The extracellular matrix of the intervertebral disc is subjected to changes with age and degeneration, affecting the biomechanical behaviour of the spine. In this study, a finite element model of a generic spinal motion segment that links spinal biomechanics and intervertebral disc biochemical composition was developed. The local mechanical properties of the tissue were described by the local matrix composition, i.e. fixed charge density, amount of water and collagen and their organisation. The constitutive properties of the biochemical constituents were determined by fitting numerical responses to experimental measurements derived from literature. This general multi-scale model of the disc provides the possibility to evaluate the relation between local disc biochemical composition and spinal biomechanics.

Abstract A23: Differentiation of PI3K/Akt/mTOR inhibition in cancer models using dual dissociative TORC1/TORC2 (P529), single dissociative TORC1 (rapalogs) and catalytic inhibitors (PI3K/Akt, PI3K/mTOR)

P529 is a first-in-class, allosteric, small molecule, dual dissociative inhibitor of the TORC1 and TORC2 protein complexes within the PI3K/Akt/mTOR pathway. P529 has been previously shown to cause the rapid dissociation of the TORC1 and TORC2 complexes both in vitro and in vivo tumor xenograft models. Other PI3K inhibitors include rapalogs which cause the dissociation of the TORC1 complex and, PI3K/mTOR and PI3K/Akt inhibitors aimed at protein kinase catalytic site inhibition. Although these inhibitors have shown some utility in inhibiting cancer growth, they have deficiencies inherent to their mechanism of action. Rapalogs have been shown to stimulate the PI3K pathway through the induction of the IRS-1 negative feedback loop. Although mTOR resides in both TORC1 and TORC2, catalytic inhibition of mTOR does not dissociate both complexes allowing other proteins within the complexes to retain and exert signalling activity. Hence they are not true dual TORC1/TORC2 inhibitors, but only mTOR inhibitors. Here we show comparison of P529 with rapalogs and the catalytic inhibitors PI3K/mTOR and PI3K/Akt delineating activity in prostate, lung, glioblastoma and hepatic tumor evaluating cell survival, phosphoprotein PI3K signaling (IC50), CT scanning, tumor volume and growth arrest in cellular models and murine xenografts, showing superiority of allosteric dual TORC1/TORC2 dissociative inhibition. Furthermore, in addition to evaluation in cancer treatment models, data will be presented showing activity in cancer prevention using the mutant EGFR (L858R/T790M) transgene lung expression model.

Citation Format: David Sherris, Philip A. Dennis, Willie Wilson, III, Shigeru Kawabata, Chunrong Yu, Giovanni Luca Gravina, Andrea Mancini, Claudio Festuccia. Differentiation of PI3K/Akt/mTOR inhibition in cancer models using dual dissociative TORC1/TORC2 (P529), single dissociative TORC1 (rapalogs) and catalytic inhibitors (PI3K/Akt, PI3K/mTOR). [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr A23.

Successful transcatheter occlusion of an anomalous pulmonary vein with dual drainage to the left atrium

We describe a case of a scimitar syndrome "variant" where dual drainage existed from the right upper and middle pulmonary veins to the inferior vena cava and left atrium. Device closure of the anomalous vein at the level of the connection to the IVC was successful in achieving diversion of pulmonary venous flow to the left atrium. Vigilance during work-up of anomalous pulmonary venous drainage (whether isolated or associated with other cardiac defects that may be amenable to device closure) is important to define the presence of dual connections to the left atrium, in which case a less-invasive transcatheter approach may be feasible.

A tissue adaptation model based on strain-dependent collagen degradation and contact-guided cell traction

Soft biological tissues adapt their collagen network to the mechanical environment. Collagen remodeling and cell traction are both involved in this process. The present study presents a collagen adaptation model which includes strain-dependent collagen degradation and contact-guided cell traction. Cell traction is determined by the prevailing collagen structure and is assumed to strive for tensional homeostasis. In addition, collagen is assumed to mechanically fail if it is over-strained. Care is taken to use principally measurable and physiologically meaningful relationships. This model is implemented in a fibril-reinforced biphasic finite element model for soft hydrated tissues. The versatility and limitations of the model are demonstrated by corroborating the predicted transient and equilibrium collagen adaptation under distinct mechanical constraints against experimental observations from the literature. These experiments include overloading of pericardium explants until failure, static uniaxial and biaxial loading of cell-seeded gels in vitro and shortening of periosteum explants. In addition, remodeling under hypothetical conditions is explored to demonstrate how collagen might adapt to small differences in constraints. Typical aspects of all essentially different experimental conditions are captured quantitatively or qualitatively. Differences between predictions and experiments as well as new insights that emerge from the present simulations are discussed. This model is anticipated to evolve into a mechanistic description of collagen adaptation, which may assist in developing load-regimes for functional tissue engineered constructs, or may be employed to improve our understanding of the mechanisms behind physiological and pathological collagen remodeling.