Bothrops Moojeni Snake Venom: A Source of Potential Therapeutic Agents Against Hemostatic Disorders

Abstract Hemostasis is a complex set of biological processes responsible for blood fluidity within normal vessels and for the physiological interruption of bleeding in cases of vascular injury. Bothrops moojeni snake venom is rich in bioactive compounds of pharmacological and clinical interest since its protein components are capable of interfering with many points of the hemostatic process. Here, we present the B. moojeni venom proteins that affect hemostasis and discuss their pharmacological and clinical potential. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Data were obtained from the CAPES Journal Portal database, using the terms "Bothrops" AND "hemostasis", in a search for scientific articles made available in the last 20 years. Many components isolated from B. moojeni snake venom are characterized for their effect on hemostasis and possible application in the diagnosis and treatment of hemostatic disorders.

Real-World Data on Combined EGFR-TKI and Crizotinib Treatment for Acquired and De Novo MET Amplification in Patients with Metastatic EGFR-Mutated NSCLC.

Amplification of the mesenchymal epithelial transition (MET) gene is a mechanism of acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine-kinase-inhibitors (TKIs) in over 20% of patients with advanced EGFR-mutated (EGFRm+) non-small lung cancer (NSCLC). However, it may also occur de novo in 2-8% of EGFRm+ NSCLC cases as a potential mechanism of intrinsic resistance. These patients represent a group with unmet needs, since there is no standard therapy currently approved. Several new MET inhibitors are being investigated in clinical trials, but the results are awaited. Meanwhile, as an alternative strategy, combinations of EGFR-TKIs with the MET/ALK/ROS1-TKI Crizotinib may be used in this setting, despite this use is principally off-label. Thus, we studied five of these MET amplified cases receiving EGFR-TKI and Crizotinib doublet after progression on EGFR-TKI treatment to assess the benefits and challenges related to this combination and the possible occurrence of genomic and phenotypic co-alterations. Furthermore, we compared our cases with other real-world reports on Crizotinib/EGFR-TKI combinations, which appeared effective, especially in patients with high-level MET amplification. Yet, we observed that the co-occurrence of other genomic and phenotypical alterations may affect the response to combined EGFR-TKI and Crizotinib. Finally, given the heterogeneity of MET amplification, the diagnostic methods for assessing it may be discrepant. In this respect, we observed that for optimal detection, immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing should be used together, as these methods possess different sensitivities and complement each other in characterizing MET amplification. Additionally, we addressed the issue of managing EGFR-mutated NSCLC patients with de novo MET amplification causing primary EGFR-TKI resistance. We conclude that, while data from clinical trials with new MET inhibitors are still pending, adding Crizotinib to EGFR-TKI in NSCLC patients acquiring MET amplification at progression on EGFR-TKI monotherapy is a reasonable approach, with a progression-free survival of 3-19 months.

Chest x-ray imaging score is associated with severity of COVID-19 pneumonia: the MBrixia score.

Spatial resolution in existing chest x-ray (CXR)-based scoring systems for coronavirus disease 2019 (COVID-19) pneumonia is low, and should be increased for better representation of anatomy, and severity of lung involvement. An existing CXR-based system, the Brixia score, was modified to increase the spatial resolution, creating the MBrixia score. The MBrixia score is the sum, of a rule-based quantification of CXR severity on a scale of 0 to 3 in 12 anatomical zones in the lungs. The MBrixia score was applied to CXR images from COVID-19 patients at a single tertiary hospital in the period May 4th-June 5th, 2020. The relationship between MBrixia score, and level of respiratory support at the time of performed CXR imaging was investigated. 37 hospitalized COVID-19 patients with 290 CXRs were identified, 22 (59.5%) were admitted to the intensive care unit and 10 (27%) died during follow-up. In a Poisson regression using all 290 MBrixia scored CXRs, a higher MBrixia score was associated with a higher level of respiratory support at the time of performed CXR. The MBrixia score could potentially be valuable as a quantitative surrogate measurement of COVID-19 pneumonia severity, and future studies should investigate the score's validity and capabilities of predicting clinical outcomes.

Baltetin: a new C-type lectin-like isolated from Bothrops alternatus snake venom which act as a platelet aggregation inhibiting.

C-type lectin-like proteins found in snake venom, known as snaclecs, have important effects on hemostasis through targeting membrane receptors, coagulation factors and other hemostatic proteins. Here, we present the isolation and functional characterization of a snaclec isolated from Bothrops alternatus venom, designated as Baltetin. We purified the protein in three chromatographic steps (anion-exchange, affinity and reversed-phase chromatography). Baltetin is a dimeric snaclec that is approximately 15 and 25 kDa under reducing and non-reducing conditions, respectively, as estimated by SDS-PAGE. Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry and Edman degradation sequencing revealed that Baltetin is a heterodimer. The first 40 amino acid residues of the N-terminal region of Baltetin subunits share a high degree of sequence identity with other snaclecs. Baltetin had a specific, dose-dependent inhibitory effect on epinephrine-induced platelet aggregation in human platelet-rich plasma, inhibiting up to 69% of platelet aggregation. Analysis of the infrared spectra suggested that the interaction between Baltetin and platelets can be attributed to the formation of hydrogen bonds between the PO32- groups in the protein and PO2- groups in the platelet membrane. This interaction may lead to membrane lipid peroxidation, which prevents epinephrine from binding to its receptor. The present work suggests that Baltetin, a new C-type lectin-like protein isolated from B. alternatus venom, is the first snaclec to inhibit epinephrine-induced platelet aggregation. This could be of medical interest as a new tool for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders.

DaPeCa-7: comparative assessment of fluorodeoxyglucose positron emission tomography/computed tomography (CT) and conventional diagnostic CT in diagnosis of lymph node metastases, distant metastases and incidental findings in patients with invasive penile cancer.

OBJECTIVES: To evaluate diagnostic accuracy of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) compared to contrast-enhanced CT in assessment of inguinal lymph node (ILN) metastases, distant metastases and synchronous cancers in patients with penile squamous cell carcinoma (pSCC). PATIENTS AND METHODS: During a 4-year period, patients with pSCC were scheduled for FDG PET/CT prior to surgical treatment at two referral centres that manage all penile cancers in Denmark. The primary endpoint was diagnostic accuracy of FDG PET/CT and of CT alone with histopathology or Response Evaluation Criteria In Solid Tumors (RECIST) as reference. RESULTS: We evaluated 171 patients for distant metastases and synchronous incident cancers and examined 286 groins in 143 patients for LN metastases by FDG PET/CT. Six groins disclosed false negatives. FDG PET/CT sensitivity was 85.4% per patient. In 135 patients (270 groins), CT images were evaluated separately and 22 groins disclosed false negatives. CT sensitivity was 47.5% per patient. FDG PET/CT detected pSCC distant metastases in seven patients. Distant metastases from other cancers were newly detected in three patients. In eight patients, an incidental synchronous cancer was detected. Seven out of the 18 distant malignancies detected depended on FDG PET information. CONCLUSION: This study underlines the increased diagnostic accuracy of FDG PET/CT compared to CT alone in the evaluation of ILN status. In patients with palpable LNs, the advantage of FDG PET/CT over CT is less pronounced. FDG PET/CT may play a role in penile cancer evaluation.

Edema, hyperalgesia and myonecrosis induced by Brazilian bothropic venoms: overview of the last decade.

Snakebite accidents are considered serious public health problems. They are often neglected, and individuals who have received insufficient treatment are subjected to various disabling alterations. Snake venoms are secretions composed of biologically active molecules capable of triggering local and systemic effects in envenomation victims. Bothropic snakes are responsible for most of the ophidian accidents in Brazil; their venoms are mainly related to local manifestations, due to a composition that is especially rich in proteases and phospholipases A2. The most common local damages are inflammation, with consequent cellular activation and release of inflammatory mediators, hemorrhage, edema, pain and (myo)necrosis, which may lead to amputation of the affected areas. Antivenom therapy is the main treatment for snakebites. However, the efficiency is mainly due to the neutralization of the toxins responsible for the systemic alterations. Thus, the local damages can evolve to markedly compromise the tissue. The complexity of these local effects associated with the toxicity of the snake venom components of the genus Bothrops, arouse interest in the study of the biochemical and pathophysiological mechanisms involved with the actions caused by toxins of the venom. Therefore, this review aims to analyze the edematogenic, hyperalgesic and myotoxic effects caused by Brazilian bothropic venoms in order to contribute to the study and elucidation of the mechanisms of action of its components and, consequently, enable discoveries of more effective combined therapies in the treatment of local damages resulting from envenoming.

Changing ALK-TKI-Resistance Mechanisms in Rebiopsies of ALK-Rearranged NSCLC: ALK- and BRAF-Mutations Followed by Epithelial-Mesenchymal Transition.

Anaplastic lymphoma-kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) is prone to developing heterogeneous, only partly known mechanisms of resistance to ALK-tyrosine-kinase-inhibitors (ALK-TKIs). We present a case of a 38-year old male, who never smoked with disseminated ALK-rearranged (EML4 (20) - ALK (20) fusion variant 2) lung adenocarcinoma, who received four sequentially different ALK-TKIs and two lines of chemotherapy in-between. We observed significant clinical benefit by the first three ALK-TKIs (Crizotinib, Ceritinib, Alectinib) and chemotherapy with Pemetrexed, resulting in overall survival over 3 years. Longitudinal assessment of progressions by rebiopsies from hepatic metastases showed different mechanisms of resistance to each ALK-TKI, including secondary ALK-mutations and the downstream p.V600E BRAF-mutation that had not been linked to second-generation ALK-TKIs before. Ultimately, in connection with terminal rapid progression and resistance to Alectinib and Lorlatinib, we identified phenotypical epithelial-mesenchymal transition (EMT) of newly occurred metastatic cells, a phenomenon not previously related to these two ALK-TKIs. This resistance heterogeneity suggests a continuously changing disease state. Sequential use of different generation's ALK-TKIs and combination therapies may yield prolonged responses with satisfactory quality of life in patients with advanced ALK-positive NSCLC. However, the development of EMT is a major hurdle and may explain rapid disease progression and lack of response to continued ALK-inhibition.

Very Early Response Evaluation by PET/MR in Patients with Lung Cancer-Timing and Feasibility.

Purpose: With the increasing number of therapy options available for patients with lung cancer, early response evaluation is needed. We performed this pilot study to assess the feasibility of early, repeated Positron emission tomography-magnetic resonance (PET/MR), the impact of timing and the capability for response prediction in lung tumors during chemotherapy. Methods: Patients with stage IV non-small cell lung cancer referred for chemotherapy were prospectively recruited. Fluorine-18-Fluorodeoxyglucose(18F-FDG)-PET/MR scans were performed prior to, during and after the first or second cycle of chemotherapy. Primary tumors were defined on all scans and size, FDG-uptake and apparent diffusion coefficient (ADC) were measured. Early response was described over time and a Standard Linear Mixed Model was applied to analyze changes over time. Results: 45 FDG-PET/MR scans were performed in 11 patients. Whereas the overall changes measured by ADC did not change significantly, there was an overall significant decrease in FDG-uptake from pre to post treatment scans. There was no difference in the FDG-uptake measured 1 or 3 weeks after therapy, but uptake measured 2 weeks after therapy differed from measurements at week 3. Changes measured in patients scanned during the first treatment cycle appeared more pronounced than during the second cycle. Conclusions: This pilot study indicates that response evaluation shortly after initiation of chemotherapy appears concordant with later evaluation and probably more reliable than evaluation midway between cycles. Responses during or after the first cycle of chemotherapy rather than during subsequent cycles are likely to be more readily measured.

Gestar o real do corpo: o direito à maternidade possível / Compulsory adoption of children of mothers who are criminalized for being drug users: the right to maternity

Os autores apresentam narrativas e relato de vivências a partir das histórias dos sujeitos acompanhados pelo Consultório de Rua, dispositivo da Rede de Saúde Mental de Belo Horizonte, apresentando o "retrato" de mulheres gestantes nas cenas de uso de drogas. Violência de gênero, racismo e criminalização da pobreza são temas transversais à vida destas mulheres, que precisam fazer um esforço descomunal para tentar garantir o direito de permanecer com a guarda de seus filhos gestados.(AU)

In this paper, the authors present a "portrait" of drug dependent pregnant women through the narratives, experiences and life stories of the individuals seen by the multidisciplinary team of the Consultório de Rua. The health service aims to reduce the negative consequences of drug use for people living on the streets as part of Belo Horizonte Mental Health Program. A profile of the drug dependent pregnant women in their challenge to maintain custody of their children despite living in circumstances defined by violence against women, criminalization of poverty and racism is addressed. (AU)

Systemic alterations induced by phospholipase A2 , BmooTX-I, isolated from Bothrops moojeni snake venom.

Ophidic accidents are among the problems of public health in Brazil. The components from bothropic venom are responsible for many systemic clinical complications resulting from envenomation. The present work aimed to analyse the systemic changes induced in mice after intraperitoneal administration of BmooTX-I, a myotoxic acidic phospholipase A2 isolated from Bothrops moojeni venom. Urinalysis was performed and the following plasma biochemical markers were documented: urea, creatinine and uric acid (renal function); glucose and amylase (pancreatic function); alanine aminotransferase, alkaline phosphatase and gamma-GT (intra- and extrahepatic function); creatine kinase and enzymatic lactate (muscle function). Our results showed that after the intraperitoneal injection of BmooTX-I the urine of these animals showed glycosuria, proteinuria, haematuria, bacteriuria, bilirubinuria, polyuria and nitrite. The plasma biochemical analysis showed alterations in levels of urea, creatinine and uric acid. Amylase concentration was not altered significantly, but the plasma glucose increased significantly compared to controls. The plasma levels of alanine aminotransferase and alkaline phosphatase decreased and increased, respectively, in these same animals. On the other hand, the plasma γGT concentration did not undergo significant modification compared to the control group. The plasma concentration of CK increased, while the enzymatic lactate concentration decreased after the injection of the BmooTX-I. Therefore, in mice BmooTX-I is capable of causing systemic alterations which manifest as renal, muscular, hepatic and pancreatic impairment.

Metal artefact reduction for accurate tumour delineation in radiotherapy.

BACKGROUND AND PURPOSE: Two techniques for metal artefact reduction for computed tomography were studied in order to identify their impact on tumour delineation in radiotherapy. MATERIALS AND METHODS: Using specially designed phantoms containing metal implants (dental, spine and hip) as well as patient images, we investigated the impact of two methods for metal artefact reduction on (A) the size and severity of metal artefacts and the accuracy of Hounsfield Unit (HU) representation, (B) the visual impact of metal artefacts on image quality and (C) delineation accuracy. A metal artefact reduction algorithm (MAR) and two types of dual energy virtual monochromatic (DECT VM) reconstructions were used separately and in combination to identify the optimal technique for each implant site. RESULTS: The artefact area and severity was reduced (by 48-76% and 58-79%, MAR and DECT VM respectively) and accurate Hounsfield-value representation was increased by 22-82%. For each energy, the observers preferred MAR over non-MAR reconstructions (p < 0.01 for dental and hip cases, p < 0.05 for the spine case). In addition, DECT VM was preferred for spine implants (p < 0.01). In all cases, techniques that improved target delineation significantly (p < 0.05) were identified. CONCLUSIONS: DECT VM and MAR techniques improve delineation accuracy and the optimal of reconstruction technique depends on the type of metal implant.

A New Platelet-Aggregation-Inhibiting Factor Isolated from Bothrops moojeni Snake Venom.

This work reports the purification and functional characterization of BmooPAi, a platelet-aggregation-inhibiting factor from Bothrops moojeni snake venom. The toxin was purified by a combination of three chromatographic steps (ion-exchange on DEAE-Sephacel, molecular exclusion on Sephadex G-75, and affinity chromatography on HiTrap™ Heparin HP). BmooPAi was found to be a single-chain protein with an apparent molecular mass of 32 kDa on 14% SDS-PAGE, under reducing conditions. Sequencing of BmooPAi by Edman degradation revealed the amino acid sequence LGPDIVPPNELLEVM. The toxin was devoid of proteolytic, haemorrhagic, defibrinating, or coagulant activities and induced no significant oedema or hyperalgesia. BmooPAi showed a rather specific inhibitory effect on ristocetin-induced platelet aggregation in human platelet-rich plasma, whereas it had little or no effect on platelet aggregation induced by collagen and adenosine diphosphate. The results presented in this work suggest that BmooPAi is a toxin comprised of disintegrin-like and cysteine-rich domains, originating from autolysis/proteolysis of PIII SVMPs from B. moojeni snake venom. This toxin may be of medical interest because it is a platelet aggregation inhibitor, which could potentially be developed as a novel therapeutic agent to prevent and/or treat patients with thrombotic disorders.

Heterogeneous resistance mechanisms in an EGFR exon 19-mutated non-small cell lung cancer patient treated with erlotinib: Persistent FGFR3-mutation, localized transformation to EGFR-mutated SCLC, and acquired T790M EGFR-mutation.

Patients with epidermal growth factor receptor (EGFR) gene-mutated non-small cell lung cancer (NSCLC) obtain substantial clinical benefit from EGFR tyrosine-kinase inhibitors (TKIs), but will ultimately develop TKI-resistance resulting in median progression-free survival of 9-15 months during first-line TKI-therapy. However, type and timing of TKI-resistance cannot be predicted and several mechanisms may simultaneously/subsequently occur during TKI-treatment. In this respect, we present a 49 year-old Caucasian male ex-smoker with metastatic pulmonary adenocarcinoma (ADC) that concomitantly harbored an EGFR exon 19-mutation (p.E746_A750delELREA) and a previously unreported 2bp frame-shift microdeletion in the fibroblast growth factor receptor 3 (FGFR3; p.D785fs*31) gene. Interestingly, FGFR3-mutations have previously been described in other cancer types of Caucasian patients and may represent an alternative pathway to EGFR-signaling. The patient received first-line erlotinib but after only 7 weeks showed metastatic pleural effusion, in which transformation to small cell lung cancer (SCLC) that retained the EGFR- and FGFR3-mutations was identified. Consequently, standard carboplatin-etoposide regimen for SCLC combined with erlotinib continuation was implemented obtaining significant objective response. However, after completing 6 cycles of this combination, new pulmonary and hepatic metastases appeared and showed persistence of the original EGFR- and FGFR3-mutated ADC phenotype together with acquisition of the erlotinib-resistant T790M EGFR-mutation. The patient rapidly deteriorated and deceased. Thus, this advanced EGFR-mutated NSCLC displayed very rapid onset and heterogeneous genetic and phenotypic mechanisms of TKI-resistance occurring at different times and locations of metastatic disease: concomitant FGFR3-mutation before and during TKI-treatment as potential intrinsic mechanism for the rapid progression; transformation to SCLC at first progression during TKI-therapy; acquired T790M EGFR-mutation at second progression. Our case also underlines that, when achievable, rebiopsies of progressive sites during TKI-treatment are important for identifying heterogeneous histopathological and molecular resistance mechanisms and better defining possible treatment modifications.

Toxicity and efficacy of re-irradiation of high-grade glioma in a phase I dose- and volume escalation trial.

INTRODUCTION: The purpose of this study was to evaluate the safety and efficacy of PET and MRI guided re-irradiation of recurrent high-grade glioma (HGG) and to assess the impact of radiotherapy dose, fractionation and irradiated volume. MATERIAL AND METHODS: Patients with localized, recurrent HGG (grades III-IV) and no other treatment options were eligible for a prospective phase I trial. Gross tumor volumes for radiotherapy were defined using T1-contrast enhanced MRI and 18F-fluoro-ethyl tyrosine PET. Radiotherapy was delivered using volumetric modulated arc therapy with a 2-mm margin. The dose prescription of four consecutive groups was (1) 35 Gy/10fr., (2) 42 Gy/10fr., (3) 29.5 Gy/5fr. and (4) 35 Gy/10fr. to larger tumor volumes (100-300 cm3), respectively. RESULTS: Thirty-one patients were treated of which 81% had glioblastoma. The median progression-free survival was 2.8 months (95%CI: 2.1-3.5) and the median overall survival was 7.0 months (95%CI: 3.5-10.5). Early side effects were mild and included headache and fatigue. Seven patients were progression-free beyond 10 weeks and were evaluable for late toxicity. Among these patients, three (43%) suffered late adverse events which included radionecrosis and irreversible white matter changes. CONCLUSION: Re-irradiation showed limited efficacy and 43% of patients achieving disease control suffered late toxicity that was manageable but not negligible.

BaltDC: purification, characterization and infrared spectroscopy of an antiplatelet DC protein isolated from Bothrops alternatus snake venom.

BACKGROUND: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. METHODS: The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. RESULTS: BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO32- groups, present in BaltDC, form hydrogen bonds with the PO2- groups present in the non-lipid portion of the membrane platelets. CONCLUSIONS: BaltDC may be of medical interest since it was able to inhibit platelet aggregation.

The role of platelets in hemostasis and the effects of snake venom toxins on platelet function.

The human body has a set of physiological processes, known as hemostasis, which keeps the blood fluid and free of clots in normal vessels; in the case of vascular injury, this process induces the local formation of a hemostatic plug, preventing hemorrhage. The hemostatic system in humans presents complex physiological interactions that involve platelets, plasma proteins, endothelial and subendothelial structures. Disequilibrium in the regulatory mechanisms that control the growth and the size of the thrombus is one of the factors that favors the development of diseases related to vascular disorders such as myocardial infarction and stroke, which are among the leading causes of death in the western world. Interfering with platelet function is a strategy for the treatment of thrombotic diseases. Antiplatelet drugs are used mainly in cases related to arterial thrombosis and interfere in the formation of the platelet plug by different mechanisms. Aspirin (acetylsalicylic acid) is the oldest and most widely used antithrombotic drug. Although highly effective in most cases, aspirin has limitations compared to other drugs used in the treatment of homeostatic disorders. For this reason, research related to molecules that interfere with platelet aggregation are of great relevance. In this regard, snake venoms are known to contain a number of molecules that interfere with hemostasis, including platelet function. The mechanisms by which snake venom components inhibit or activate platelet aggregation are varied and can be used as tools for the diagnosis and the treatment of several hemostatic disorders. The aim of this review is to present the role of platelets in hemostasis and the mechanisms by which snake venom toxins interfere with platelet function.

Patterns of failure for patients with glioblastoma following O-(2-[18F]fluoroethyl)-L-tyrosine PET- and MRI-guided radiotherapy.

BACKGROUND AND PURPOSE: To evaluate the patterns of failure following clinical introduction of amino-acid O-(2-[18F]fluoroethyl)-L-tyrosine (FET)-PET-guided target definition for radiotherapy (RT) of glioblastoma patients. MATERIALS AND METHODS: The first 66 consecutive patients with confirmed histology, scanned using FET-PET/CT and MRI were selected for evaluation. Chemo-radiotherapy was delivered to a volume based on both MRI and FET-PET (PETvol). The volume of recurrence (RV) was defined on MRI data collected at the time of progression according to RANO criteria. RESULTS: Fifty patients were evaluable, with median follow-up of 45months. Central, in-field, marginal and distant recurrences were observed for 82%, 10%, 2%, and 6% of the patients, respectively. We found a volumetric overlap of 26%, 31% and 39% of the RV with the contrast-enhancing MR volume, PETvol and the composite MRPETvol, respectively. MGMT-methylation (p=0.03), larger PETvol (p<0.001), and less extensive surgery (p<0.001), were associated with larger PETvol overlap. CONCLUSION: The combined MRPETvol had a stronger association with the recurrence volume than either of the modalities alone. Larger overlap of PETvol and RV was observed for patients with MGMT-methylation, less extensive surgery, and large PETvol on the RT-planning scans.

Feasibility of Multiparametric Imaging with PET/MR in Head and Neck Squamous Cell Carcinoma.

The purpose of this study was to investigate and assess the correlation and reproducibility of multiparametric imaging in head and neck cancer patients. METHODS: Twenty-one patients were included in this prospective scan-rescan study. All patients were scanned twice on an integrated PET and MRI scanner. Gross tumor volumes were defined on T2-weighted MR images, and volumes of interest were defined on diffusion-weighted MRI and 18F-FDG PET (VOIDWI, VOIPET). Overlap between volumes was assessed as a percentwise overlap. 18F-FDG uptake and diffusion were measured using SUV and apparent diffusion coefficient, and correlation was tested across and within patients and as a voxel-by-voxel analysis. RESULTS: Seventeen patients were available for correlation analysis, and 12 patients were available for assessment of tumor overlap. The median tumor overlap between VOIDWI and VOIPET was 82% (VOIDWI in VOIPET) and 62% (VOIPET in VOIDWI) on scan 1 and scan 2, respectively. Across patients, the correlation between SUV and apparent diffusion coefficient was weak and nonsignificant. However, in individual patients a weak but significant correlation was identified on a voxel-by-voxel basis. CONCLUSION: In multiparametric imaging with the integrated PET/MR scanner, the VOIs from DWI and 18F-FDG PET were both within the target volume for radiotherapy and overlapped substantially although not completely. No correlation between 18F-FDG uptake and DWI could be found across patients, but within individual patients a statistically significant, but weak, voxel-by-voxel correlation was found. The findings suggest that information on glucose uptake and diffusion coefficient carries complementary information of interest that may be relevant for radiotherapy treatment planning.

BaltDC: purification, characterization and infrared spectroscopy of an antiplatelet DC protein isolated from Bothrops alternatus snake venom

Background: Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. Methods: The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. Results: BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO 3 2 − groups, present in BaltDC, form hydrogen bonds with the PO 2 − groups present in the non-lipid portion of the membrane platelets. Conclusions: BaltDC may be of medical interest since it was able to inhibit platelet aggregation.(AU)