58 research outputs found

    A bicyclic α-iminophosphonate improves cognitive decline in 5xFAD murine model of neurodegeneration

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    I2 receptors (I2-IR) are widely distributed in the central nervous system. I2-IR ligands are associated with a neuroprotective effect but, as I2-IR structure remains unknown, the discovery of better and more selective ligands is necessary to understand the pharmacological and molecular implications of I2-IR. Recently, we described a new imidazoline-structure family which showed high affinity and selectivity for I2-IR. In vivo studies in mice indicated a neuroprotective role and revealed beneficial effects in behaviour and cognition with a murine model of neurodegeneration, senescence-accelerated prone mouse (SAMP8). Herein, we report a novel non-imidazoline-structure of bicyclic α-iminophosphonates family with high affinities for I2-IR. In vivo studies in 5X-FAD mice (a transgenic representative model of AD) and SAMP8 mice (a model of neurodegeneration linked to aging) showed an improvement in behaviour and cognition, a reduction of AD hallmarks and of neuroinflammation markers for the mice treated with the lead compound B06. After evaluating several pathways associated with neurodegeneration, we demonstrated that CaN pathway plays a critical role on the neuroprotective effects of I2-IR ligands on SAMP8 mice model. To rule out warnings of the novel family, we calculated DMPK and physicochemical properties for the novel bicyclic α-iminophosphonates. As well, we carried out drug metabolism, safety studies and in vivo pharmacokinetics for lead compound B06. In summary, we present a novel family of I2-IR ligands, its effectiveness in in vivo models and the possible neuroprotective molecular mechanism mediated by them. This highlights that the modulation of I2-IR by bicyclic α-iminophosphonates may open a new therapeutic venue for unmet neurodegenerative conditions

    Cold non-ischemic heart preservation with continuous perfusion prevents early graft failure in orthotopic pig-to-baboon xenotransplantation

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    Background Successful preclinical transplantations of porcine hearts into baboon recipients are required before commencing clinical trials. Despite years of research, over half of the orthotopic cardiac xenografts were lost during the first 48 hours after transplantation, primarily caused by perioperative cardiac xenograft dysfunction (PCXD). To decrease the rate of PCXD, we adopted a preservation technique of cold non-ischemic perfusion for our ongoing pig-to-baboon cardiac xenotransplantation project. Methods Fourteen orthotopic cardiac xenotransplantation experiments were carried out with genetically modified juvenile pigs (GGTA1- KO/hCD46/hTBM) as donors and captive-bred baboons as recipients. Organ preservation was compared according to the two techniques applied: cold static ischemic cardioplegia (IC; n = 5) and cold non-ischemic continuous perfusion (CP; n = 9) with an oxygenated albumin-containing hyperoncotic cardioplegic solution containing nutrients, erythrocytes and hormones. Prior to surgery, we measured serum levels of preformed anti-non-Gal-antibodies. During surgery, hemodynamic parameters were monitored with transpulmonary thermodilution. Central venous blood gas analyses were taken at regular intervals to estimate oxygen extraction, as well as lactate production. After surgery, we measured troponine T and serum parameters of the recipient's kidney, liver and coagulation functions. Results In porcine grafts preserved with IC, we found significantly depressed systolic cardiac function after transplantation which did not recover despite increasing inotropic support. Postoperative oxygen extraction and lactate production were significantly increased. Troponin T, creatinine, aspartate aminotransferase levels were pathologically high, whereas prothrombin ratios were abnormally low. In three of five IC experiments, PCXD developed within 24 hours. By contrast, all nine hearts preserved with CP retained fully preserved systolic function, none showed any signs of PCXD. Oxygen extraction was within normal ranges; serum lactate as well as parameters of organ functions were only mildly elevated. Preformed anti-non-Gal-antibodies were similar in recipients receiving grafts from either IC or CP preservation. Conclusions While standard ischemic cardioplegia solutions have been used with great success in human allotransplantation over many years, our data indicate that they are insufficient for preservation of porcine hearts transplanted into baboons: Ischemic storage caused severe impairment of cardiac function and decreased tissue oxygen supply, leading to multi-organ failure in more than half of the xenotransplantation experiments. In contrast, cold non-ischemic heart preservation with continuous perfusion reliably prevented early graft failure. Consistent survival in the perioperative phase is a prerequisite for preclinical long-term results after cardiac xenotransplantation

    Bicyclic alfa-iminophosphonates as high affinity imidazoline I2 receptor ligands for Alzheimer's disease

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    Imidazoline I2 receptors (I2-IR), widely distributed in the CNS and altered in patients that suffered from neurodegenerative disorders, are orphan from the structural point of view and new I2-IR ligands are urgently required for improving their pharmacological characterization. We report the synthesis and 3D-QSAR studies of a new family of bicyclic α-iminophosphonates endowed with relevant affinities for human brain I2-IR. Acute treatment in mice with a selected compound significantly decreased the FADD protein in the hippocampus, a key marker in neuroprotective actions. Additionally, in vivo studies in the familial Alzheimer's disease 5xFAD murine model revealed beneficial effects in behavior and cognition. These results are supported by changes in molecular pathways related to cognitive decline and Alzheimer's disease. Therefore bicyclic α-iminophosphonates are tools that may open new therapeutic avenues for I2-IR, particularly for unmet neurodegenerative conditions

    Combined approach of perioperative 18F-FDG PET/CT imaging and intraoperative 18F-FDG handheld gamma probe detection for tumor localization and verification of complete tumor resection in breast cancer

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    <p>Abstract</p> <p>Background</p> <p><sup>18</sup>F-fluorodeoxyglucose (<sup>18</sup>F-FDG) positron emission tomography/computed tomography (PET/CT) has become an established method for detecting hypermetabolic sites of known and occult disease and is widely used in oncology surgical planning. Intraoperatively, it is often difficult to localize tumors and verify complete resection of tumors that have been previously detected on diagnostic PET/CT at the time of the original evaluation of the cancer patient. Therefore, we propose an innovative approach for intraoperative tumor localization and verification of complete tumor resection utilizing <sup>18</sup>F-FDG for perioperative PET/CT imaging and intraoperative gamma probe detection.</p> <p>Methods</p> <p>Two breast cancer patients were evaluated. <sup>18</sup>F-FDG was administered and PET/CT was acquired immediately prior to surgery. Intraoperatively, tumors were localized and resected with the assistance of a handheld gamma probe. Resected tumors were scanned with specimen PET/CT prior to pathologic processing. Shortly after the surgical procedure, patients were re-imaged with PET/CT utilizing the same preoperatively administered <sup>18</sup>F-FDG dose.</p> <p>Results</p> <p>One patient had primary carcinoma of breast and a metastatic axillary lymph node. The second patient had a solitary metastatic liver lesion. In both cases, preoperative PET/CT verified these findings and demonstrated no additional suspicious hypermetabolic lesions. Furthermore, intraoperative gamma probe detection, specimen PET/CT, and postoperative PET/CT verified complete resection of the hypermetabolic lesions.</p> <p>Conclusion</p> <p>Immediate preoperative and postoperative PET/CT imaging, utilizing the same <sup>18</sup>F-FDG injection dose, is feasible and image quality is acceptable. Such perioperative PET/CT imaging, along with intraoperative gamma probe detection and specimen PET/CT, can be used to verify complete tumor resection. This innovative approach demonstrates promise for assisting the oncologic surgeon in localizing and verifying resection of <sup>18</sup>F-FDG positive tumors and may ultimately positively impact upon long-term patient outcomes.</p

    AMPLIFICATION OF CYCLINE D1, C-MYC AND EGFR ONCOGENES IN TUMOUR SAMPLES OF BREAST CANCER PATIENTS AMPLIFIKACIJA CIKLIN D1, C-MYC AND EGFR ONKOGENA U TUMORSKIM UZORCIMA PACIJENTKINJA OBOLELIH OD KANCERA DOJKE

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    Summary Background: Breast cancer is the most common form of cancer in women. It arises from multiple genetic changes in oncogenes and tumor suppressor genes. Among so far studied oncogenes relatively few, including epdermal growth factor receptor (EGFR), cyclinD1 (CCND1)and cmyc, have been found to play an important role in progression of this type of human malignancy. The aim of this study was to examine the prognostic potential of CCND1, c-myc and EGFR amplification and their possible cooperation in breast carcinogenesis. Methods: Copy number analyses of CCND1 and c-myc genes were done by TaqMan based quantitative real time PCR. Am pli fication status of EGFR was determined by differential PCR

    Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging

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    In the last decade, PET-only systems have been phased out and replaced with PET-CT systems. This merger of a functional and anatomical imaging modality turned out to be extremely useful in clinical practice. Currently, PET-CT is a major diagnostic tool in oncology. At the dawn of the merger of MRI and PET, another breakthrough in clinical imaging is expected. The combination of these imaging modalities is challenging, but has particular features such as imaging biological processes at the same time in specific body locations

    Maternal outcomes and risk factors for COVID-19 severity among pregnant women.

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    Pregnant women may be at higher risk of severe complications associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which may lead to obstetrical complications. We performed a case control study comparing pregnant women with severe coronavirus disease 19 (cases) to pregnant women with a milder form (controls) enrolled in the COVI-Preg international registry cohort between March 24 and July 26, 2020. Risk factors for severity, obstetrical and immediate neonatal outcomes were assessed. A total of 926 pregnant women with a positive test for SARS-CoV-2 were included, among which 92 (9.9%) presented with severe COVID-19 disease. Risk factors for severe maternal outcomes were pulmonary comorbidities [aOR 4.3, 95% CI 1.9-9.5], hypertensive disorders [aOR 2.7, 95% CI 1.0-7.0] and diabetes [aOR2.2, 95% CI 1.1-4.5]. Pregnant women with severe maternal outcomes were at higher risk of caesarean section [70.7% (n = 53/75)], preterm delivery [62.7% (n = 32/51)] and newborns requiring admission to the neonatal intensive care unit [41.3% (n = 31/75)]. In this study, several risk factors for developing severe complications of SARS-CoV-2 infection among pregnant women were identified including pulmonary comorbidities, hypertensive disorders and diabetes. Obstetrical and neonatal outcomes appear to be influenced by the severity of maternal disease
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