New Fully Automated Preparation of High Apparent Molar Activity 68Ga-FAPI-46 on a Trasis AiO Platform.

A large number of applications for fibroblast activation protein inhibitors (FAPI)-based PET agents have been evaluated in conditions ranging from cancer to non-malignant diseases such as myocardial infarction. In particular, 68Ga-FAPI-46 was reported to have a high specificity and affinity for FAP-expressing cells, a fast and high accumulation in tumor lesions/injuries together with a fast body clearance when investigated in vivo. Due to the increasing interest in the use of the agent both preclinically and clinically, we developed an automated synthesis for the production of 68Ga-FAPI-46 on a Trasis AiO platform. The new synthetic procedure, which included the processing of the generator eluate using a strong cation exchange resin and a final purification step through an HLB followed by a QMA cartridge, yielded 68Ga-FAPI-46 with high radiochemical purity (>98%) and apparent molar activity (271.1 ± 105.6 MBq/nmol). Additionally, the in vitro and in vivo properties of the product were assessed on glioblastoma cells and mouse model. Although developed for the preparation of 68Ga-FAPI-46 for preclinical use, our method can be adapted for clinical production as a reliable alternative to the manual (i.e., cold kit) or modular systems preparations already described in the literature.

Does chest wall conformation influence myocardial strain parameters in infants with pectus excavatum?

PURPOSE: To investigate the possible influence of chest wall conformation on myocardial strain parameters in a consecutive population of infants with pectus excavatum (PE), noninvasively assessed by modified Haller index (MHI). METHODS: Sixteen consecutive PE infants (MHI >2.5) and 44 infants with normal chest shape (MHI ≤2.5) entered in this prospective case-control study. All infants underwent evaluation by neonatologist, transthoracic echocardiography implemented with two-dimensional speckle tracking echocardiography (2D-STE) analysis of both ventricles and MHI assessment (ratio of chest transverse diameter over the distance between sternum and spine), at two time points: within 3 days and at about 40 days of life. RESULTS: At 2.1 ± 1 days of life, compared to controls (MHI = 2.01 ± 0.2), PE infants (MHI = 2.76 ± 0.2) were diagnosed with significantly smaller cardiac chambers dimensions. Biventricular contractile function and hemodynamics were similar in both groups of infants. Left ventricular (LV) global longitudinal strain (GLS) (-16.0 ± 2.8 vs. -21.7 ± 2.2%), LV-global circumferential strain (GCS) (-16.3 ± 2.7 vs. -24.0 ± 5.2%), LV-global radial strain (GRS) (24.2 ± 3.0 vs. 31.5 ± 6.3%), and right ventricular free wall longitudinal strain (RVFWLS) (-16.0 ± 3.2 vs. -22.3 ± 4.4%) were significantly reduced in PE infants versus controls (all p < 0.001). A strong inverse correlation between MHI and the following parameters: LV-GLS (r = -0.92), LV-GCS (r = -0.88), LV-GRS (r = -0.87), and RVFWLS (r = -0.88), was demonstrated in PE infants, but not in controls, in perinatal period (all p < 0.001). Analogous results were obtained at 36.8 ± 5.2 days after birth. CONCLUSIONS: Abnormal chest anatomy progressively impairs myocardial strain parameters in PE infants. This impairment might reflect intraventricular dyssynchrony due to compressive phenomena rather than intrinsic myocardial dysfunction.

Development and Evaluation of an 18F-Radiolabeled Monocyclam Derivative for Imaging CXCR4 Expression.

In humans, C-X-C chemokine receptor type 4 (CXCR4) is a protein that is encoded by the CXCR4 gene and binds the ligand CXCL12 (also known as SDF-1). The CXCR4-CXCL12 interaction in cancer elicits biological activities that result in tumor progression and has accordingly been the subject of significant investigation for detection and treatment of the disease. Peptidic antagonists have been labeled with a variety of radioisotopes for the detection of CXCR4, but the methodology utilizing small molecules has predominantly used radiometals. We report here the development of a 18F-radiolabeled cyclam-based small molecule radioprobe, [18F]MCFB, for imaging CXCR4 expression. The IC50 value of [19F]MCFB for CXCR4 was similar to that of AMD3465 (111.3 and 89.8 nM, respectively). In vitro binding assays show that the tracer depicted a differential CXCR4 expression, which was blocked in the presence of AMD3465, demonstrating the specificity of [18F]MCFB. Positron emission tomography (PET) imaging studies showed a distinct uptake of the radioprobe in lymphoma and breast cancer xenografts. High liver and kidney uptakes were seen with [18F]MCFB, leading us to further examine the basis of its pharmacokinetics in relation to the tracer's cationic nature and thus the role of organic cation transporters (OCTs). Substrate competition following the intravenous injection of metformin led to a marked decrease in the urinary excretion of [18F]MCFB, with moderate changes observed in other organs, including the liver. Our results suggest involvement of OCTs in the renal elimination of the tracer. In conclusion, the 18F-radiolabeled monocyclam, [18F]MCFB, has potential to detect tumor CXCR4 in nonhepatic tissues.

Access to hearing health service in Curitiba-PR for the elderly with hearing loss and tinnitus.

OBJECTIVE: To determine the incidence of complaints of hearing loss and tinnitus in a group of seniors and their access to hearing health services in the city of Curitiba. METHOD: 578 elderly, attending general practice clinic of two public hospitals in the city. Three questionnaires were applied: for user identification, to check for hearing loss/tinnitus and on access to hearing health services. RESULTS: Of the 578 subjects, 187 (31%) had hearing complaints and 112 (20%) had tinnitus; of these, 72% have never had an audiological evaluation, 12% received treatment for tinnitus without success, 16% reported having hearing aids, 14% had hearing aid devices managed by SUS; 76% of the sample showed the desire to carry out an assessment and be awarded hearing aids; 37% did not know where to seek help. CONCLUSION: The number of individuals with hearing complaints in the studied group is significant, as is the number of people with hearing complaints such as tinnitus who have never had a hearing examination. The access of people to public programs is deficient in this group.

Twelve-year trends in unprotected left main coronary artery occlusion: insights from a real-world multicentre study.

AIMS: Acute myocardial infarction (AMI) resulting from unprotected left main coronary artery (LMCA) occlusion and subtotal occlusion is a life-threatening condition. Although AMI management has improved in the past two decades, there is limited information on recent trends in patient characteristics, management, and outcomes for acute unprotected LMCA-related AMI. This study aims to assess such trends over a 12 year period. METHODS AND RESULTS: This retrospective multicentre study includes patients with unprotected LMCA occlusion/subtotal occlusion admitted to three tertiary hospitals between 2008 and 2020. The patients were divided into two groups based on the chronology of presentation: a 'past group' (January 2008 to December 2014) and a 'contemporary group' (January 2015 to December 2020). The study compares clinical characteristics, management approaches, and outcomes between the two groups. The study includes 128 patients, with 51 (40%) in the 'past group' and 77 (60%) in the 'contemporary group'. Baseline risk factors did not show statistically significant differences between the two groups, except for hypertension (49% vs. 74%; P = 0.005). Chest pain was more frequent in the 'past group' (98% vs. 89%; P = 0.014), and a trend towards more cardiac arrests was observed in the 'contemporary group' (18% vs. 31%; P = 0.087). Revascularization type did not differ significantly (P = 0.419), but manual thrombectomy was less frequently used (41% vs. 23%; P = 0.032) and stent implantation showed a trend towards higher rates (66% vs. 78%; P = 0.150) in the 'contemporary cohort'. There was a gradual shift from bare-metal to drug-eluting stents, with a significantly higher percentage of ticagrelor/prasugrel loading in the 'contemporary cohort' (5% vs. 79%; P < 0.001). The use of mechanical circulatory support (MCS), although not statistically significant, was higher among patients in the 'past group' (67% vs. 51%; P = 0.073). The type of MCS differed significantly between groups, with a decrease in intra-aortic balloon pump use (67% vs. 42%; P = 0.005) and an increase in veno-arterial extracorporeal membrane oxygenation (4% vs. 22%; P = 0.005) and Impella system (0% vs. 3%) over time. Survival analysis showed no significant differences (P = 0.599; log-rank test) in all-cause mortality between the different time groups, with the long-term survival rate being approximately 30%. CONCLUSIONS: In our real-world population, despite the progressive use of newer drugs and more advanced devices over time, patients with unprotected LMCA occlusion/subtotal occlusion remain a subpopulation with poor prognosis.

The impact of gender medicine on neonatology: the disadvantage of being male: a narrative review.

This narrative non-systematic review addresses the sex-specific differences observed both in prenatal period and, subsequently, in early childhood. Indeed, gender influences the type of birth and related complications. The risk of preterm birth, perinatal diseases, and differences on efficacy for pharmacological and non-pharmacological therapies, as well as prevention programs, will be evaluated. Although male newborns get more disadvantages, the physiological changes during growth and factors like social, demographic, and behavioural reverse this prevalence for some diseases. Therefore, given the primary role of genetics in gender differences, further studies specifically targeted neonatal sex-differences will be needed to streamline medical care and improve prevention programs.

Immuno-PET Imaging of Tumour PD-L1 Expression in Glioblastoma.

There is no established method to assess the PD-L1 expression in brain tumours. Therefore, we investigated the suitability of affibody molecule (ZPD-L1) radiolabelled with F-18 (Al18F) and Ga-68 to measure the expression of PD-L1 in xenograft mouse models of GBM. Mice bearing subcutaneous and orthotopic tumours were imaged 1 h post-radioconjugate administration. Ex vivo biodistribution studies and immunohistochemistry (IHC) staining were performed. Tumoural PD-L1 expression and CD4+/CD8+ tumour-infiltrating lymphocytes were evaluated in human GBM specimens. ZPD-L1 was radiolabelled with radiochemical yields of 32.2 ± 4.4% (F-18) and 73.3 ± 1.8% (Ga-68). The cell-associated radioactivity in vitro was consistent with PD-L1 expression levels assessed with flow cytometry. In vivo imaging demonstrated that 18F-AlF-NOTA-ZPD-L1 can distinguish between PD-L1 high-expressing tumours (U87-MGvIII) and PD-L1-negative ones (H292PD-L1Ko). The radioconjugate was quickly cleared from the blood and normal tissues, allowing for high-contrast images of brain tumours as early as 1 h post-injection. 68Ga-NOTA-ZPD-L1 showed heterogeneous and diffuse accumulation that corresponded to the extensively infiltrating GCGR-E55 tumours involving contiguous lobes of the brain. Lastly, 39% of analysed GBM patient samples showed PD-L1+ staining of tumour cells that was associated with elevated levels of CD4+ and CD8+ lymphocytes. Our results suggest that the investigated radioconjugates are very promising agents with the potential to facilitate the future design of treatment regimens for GBM patients.

Acute total occlusion of the unprotected left main coronary artery: Patient characteristics and outcomes.

INTRODUCTION AND OBJECTIVES: Acute total occlusion of the unprotected left main coronary artery (LMCA) is a dramatic event. There are limited data regarding this population. We aimed to describe the clinical presentation and outcomes of patients and to determine predictors of in-hospital mortality. METHODS: This retrospective study included patients presenting with acute (<12 h) myocardial infarction due to total occlusion of the LMCA (TIMI flow 0) between January 2008 and December 2020 in three tertiary hospitals. RESULTS: During this period, 11036 emergent coronary angiographies were performed, 59 (0.5%) of which revealed acute total occlusion of the LMCA. Patients' mean age was 61.2 (SD±12.2) years and 73% were male. No patients had left dominance. At presentation, 73% were in cardiogenic shock, aborted cardiac arrest occurred in 27% and 97% underwent myocardial revascularization. Primary percutaneous coronary intervention was performed in 90% of cases and angiographic success was achieved in 56% of procedures, while 7% of patients underwent surgical revascularization. In-hospital mortality was 58%. Among survivors, 92% and 67% were alive after one and five years, respectively. After multivariate analysis, only cardiogenic shock and angiographic success were independent predictors of in-hospital mortality. Use of mechanical circulatory support and presence of well-developed collateral circulation were not predictive of short-term prognosis. CONCLUSION: Acute total occlusion of the LMCA is associated with a dismal prognosis. Cardiogenic shock and angiographic success play a major role in predicting the prognosis of these patients. The effect of mechanical circulatory support on patient prognosis remains to be determined.

Post-acute sequelae of COVID-19 is characterized by diminished peripheral CD8+ß7 integrin+ T cells and anti-SARS-CoV-2 IgA response.

Several millions of individuals are estimated to develop post-acute sequelae SARS-CoV-2 condition (PASC) that persists for months after infection. Here we evaluate the immune response in convalescent individuals with PASC compared to convalescent asymptomatic and uninfected participants, six months following their COVID-19 diagnosis. Both convalescent asymptomatic and PASC cases are characterised by higher CD8+ T cell percentages, however, the proportion of blood CD8+ T cells expressing the mucosal homing receptor ß7 is low in PASC patients. CD8 T cells show increased expression of PD-1, perforin and granzyme B in PASC, and the plasma levels of type I and type III (mucosal) interferons are elevated. The humoral response is characterized by higher levels of IgA against the N and S viral proteins, particularly in those individuals who had severe acute disease. Our results also show that consistently elevated levels of IL-6, IL-8/CXCL8 and IP-10/CXCL10 during acute disease increase the risk to develop PASC. In summary, our study indicates that PASC is defined by persisting immunological dysfunction as late as six months following SARS-CoV-2 infection, including alterations in mucosal immune parameters, redistribution of mucosal CD8+ß7Integrin+ T cells and IgA, indicative of potential viral persistence and mucosal involvement in the etiopathology of PASC.

Design, synthesis, and evaluation of a novel PET imaging agent targeting lipofuscin in senescent cells.

Promoting a senescent phenotype to suppress tumour progression may present an alternative strategy for treating cancer and encourages the development of positron emission tomography (PET) imaging biomarkers for assessing response to treatment. The accumulation of lipofuscin deposits in senescent cells is visualised using the pathology stain Sudan Black B (SBB) which is an emerging biomarker of senescence. We describe the design, synthesis and evaluation of [18F]fluoroethyltriazole-SBB ([18F]FET-SBB), a fluorine-18 radiolabelled derivative of SBB. The in vitro uptake of [18F]FET-SBB in a senescent cell line corelated with lipofuscin deposits; in vivo PET imaging and metabolite analysis confirm a favourable pharmacokinetic and metabolic profile for further studies of in vivo models of senescence.

Chest Shape Influences Ventricular-Arterial Coupling Parameters in Infants with Pectus Excavatum.

Background: The present study was designed to investigate the possible influence of chest shape, noninvasively assessed by modified Haller index (MHI), on ventricular-arterial coupling (VAC) parameters in a population of term infants with pectus excavatum (PE). Methods: Sixteen consecutive PE infants (MHI >2.5) and 44 infants with normal chest shape (MHI ≤2.5) were prospectively analyzed. All infants underwent evaluation by a neonatologist, transthoracic echocardiography, and MHI assessment (ratio of chest transverse diameter over the distance between sternum and spine) within 3 days of life. Arterial elastance index (EaI) was determined as end-systolic pressure (ESP)/stroke volume index, whereas end-systolic elastance index (EesI) was measured as ESP/left ventricular end-systolic volume index. Finally, VAC was derived by the Ea/Ees ratio. Results: At 2.1 ± 1 days after birth, compared to controls (MHI = 2.01 ± 0.2), PE infants (MHI = 2.76 ± 0.2) were diagnosed with significantly smaller size of all cardiac chambers. Biventricular systolic function, left ventricular filling pressures, and pulmonary hemodynamics were similar in both the groups of infants. Both EaI (4.4 ± 1.0 mmHg/ml/m2 vs. 3.4 ± 0.6 mmHg/ml/m2, P < 0.001) and EesI (15.1 ± 3.0 mmHg/ml/m2 vs. 12.7 ± 2.5 mmHg/ml/m2, P = 0.003) were significantly increased in PE infants than controls. The resultant VAC (0.30 ± 0.10 vs. 0.30 ± 0.08, P > 0.99) was similar in both the groups of infants. Both EaI (r = 0.93) and EesI (r = 0.87) were linearly correlated with MHI in PE infants, but not in controls. On the other hand, no correlation was found between MHI and VAC in both the groups of infants. Conclusions: Chest deformity strongly influences both Ea and Ees in PE infants, due to extrinsic cardiac compression, in the absence of any intrinsic cardiovascular dysfunction.

Comprehensive assessment of biventricular myocardial function by two-dimensional speckle tracking echocardiography in infants of gestational diabetic mothers.

AIMS: No previous research provided a complete biventricular and multidirectional left ventricular (LV) functional assessment by two-dimensional (2D) speckle tracking echocardiography (STE) in infants of gestational diabetic mothers (IGDM) METHODS: A total of 30 consecutive IGDM and 30 infants of healthy mothers were examined between March 2021 and July 2021. Both groups of infants underwent evaluation by neonatologist and 2D transthoracic echocardiography (TTE) implemented with 2D-STE quantification of LV-global longitudinal strain (GLS), LV-global circumferential strain (GCS), LV-global radial strain (GRS) and right ventricular (RV)-GLS, within 3 days of life and at 40 days after birth. Predictors of persistent subclinical myocardial dysfunction, defined as a LVGLS less negative than -20% at 40-day follow-up, in IGDM population, were determined. RESULTS: At 2.2 ± 1.3 days after birth, LV-GLS (- 17.2 ± 1.9 vs. - 23.9 ± 3.8%), LV-GCS (- 17.9 ± 2.7 vs. - 27.3 ± 3.4%), LV-GRS (25.6 ± 3.4 vs. 35.8 ± 3.6%) and RV-GLS (- 17.6 ± 3.6 vs. - 22.6 ± 3.8%) were significantly impaired in IGDM than controls (all p < 0.001). At 36.8 ± 5.2 days of life, LV-GLS was still impaired (less negative than -20%) in 26.6% of IGDM. Maternal third trimester body mass index (BMI) (OR 1.89, 95%CI 1.05-3.39) and third trimester glycosylated hemoglobin (HbA1C) (OR 1.59, 95%CI 1.08-2.19) were independently associated with persistent LV-GLS impairment in IGDM. Maternal BMI ≥ 30 Kg/m2 and HbA1C ≥ 38 mmol/mol showed the maximum of sensitivity and specificity for predicting persistent subclinical myocardial dysfunction in IGDM at 40 days of life. CONCLUSIONS: IGDM have diffuse pattern of myocardial dysfunction during perinatal period. This dysfunction may be persistent up to 40 days of life in infants of GDM women with obesity and uncontrolled diabetes.

Acute Myocarditis: A New Manifestation of Monkeypox Infection?

A 31-year-old male patient with confirmed monkeypox infection developed acute myocarditis days after the eruption of skin lesions. Cardiac magnetic resonance study confirmed myocardial inflammation. The patient was treated with supportive care and had full clinical recovery. This case highlights cardiac involvement as a potential complication associated with monkeypox. (Level of Difficulty: Intermediate.).

Epigenetic potentiation of somatostatin-2 by guadecitabine in neuroendocrine neoplasias as a novel method to allow delivery of peptide receptor radiotherapy.

BACKGROUND: Somatostatin receptor-2 (SSTR2) is expressed on cell surface of neuroendocrine neoplasias; its presence is exploited for the delivery of peptide receptor radionuclide therapy (PRRT). Patients with no or low expression of SSTR2 are not candidates for PRRT. SSTR2 promotor undergoes epigenetic modification, known to regulate gene expression. We investigated whether the demethylation agent, guadecitabine, could enhance the expression of SSTR2 in NET models, using radioligand uptake/PET imaging as a biomarker of epigenetic modification. METHODS: The effects of guadecitabine on the transcriptional, translational, and functional regulation of SSTR2 both in vitro and in vivo using low (QGP-1) and high (BON-1) methylated neuroendocrine neoplasia models was characterised. Promotor region methylation profiling of clinical samples (n = 61) was undertaken. Safety of combination guadecitabine and PRRT was assessed in vivo. RESULTS: Pyrosequencing of cell lines illustrated differential methylation indices - BON: 1 94%, QGP: 1 21%. Following guadecitabine treatment, a dose-dependent increase in SSTR2 in BON-1 at a transcriptional, translational, and functional levels using the SSTR2-directed radioligand, 18F-FET-ßAG-TOCA ([18F]-FETO) (150% increase [18F]-FETO uptake, p < 0.05) was observed. In vivo, guadecitabine treatment resulted in a 70% increase in [18F]-FETO uptake in BON-1 tumour models compared models with low baseline percentage methylation (p < 0.05). No additive toxicity was observed with the combination treatment of PRRT and guadecitabine in vivo. Methylation index in clinical samples was 10.5% compared to 5.2% in controls (p = 0.03) and correlated with SSTR2 expression (Wilcoxon rank sign -3.75,p < 0.01). CONCLUSION: Guadecitabine increases SSTR2 expression both in vitro and in vivo. The combination of demethylation agents with PRRT warrants further investigation.

Prediction of Noninvasive Ventilation Failure in COVID-19 Patients: When Shall We Stop?

INTRODUCTION: In coronavirus disease 2019 (COVID-19), there are no tools available for the difficult task of recognizing which patients do not benefit from maintaining respiratory support, such as noninvasive ventilation (NIV). Identifying treatment failure is crucial to provide the best possible care and optimizing resources. Therefore, this study aimed to build a model that predicts NIV failure in patients who did not progress to invasive mechanical ventilation (IMV). METHODS: This retrospective observational study included critical COVID-19 patients treated with NIV who did not progress to IMV. Patients were admitted to a Portuguese tertiary hospital between October 1, 2020, and March 31, 2021. The outcome of interest was NIV failure, defined as COVID-19-related in-hospital death. A binary logistic regression was performed, where the outcome (mortality) was the dependent variable. Using the independent variables of the logistic regression a decision-tree classification model was implemented. RESULTS: The study sample, composed of 103 patients, had a mean age of 66.3 years (SD=14.9), of which 38.8% (40 patients) were female. Most patients (82.5%) were autonomous for basic activities of daily living. The prediction model was statistically significant with an area under the curve of 0.994 and a precision of 0.950. Higher age, a higher number of days with increases in the fraction of inspired oxygen (FiO2), a higher number of days of maximum expiratory positive airway pressure, a lower number of days on NIV, and a lower number of days from disease onset to hospital admission were, with statistical significance, associated with increased odds of death. A decision-tree classification model was then obtained to achieve the best combination of variables to predict the outcome of interest. CONCLUSIONS: This study presents a model to predict death in COVID-19 patients treated with NIV in patients who did not progress to IMV, based on easily applicable variables that mainly reflect patients' evolution during hospitalization. Along with the decision-tree classification model, these original findings may help clinicians define the best therapeutical approach to each patient, prioritizing life-comforting measures when adequate, and optimizing resources, which is crucial within limited or overloaded healthcare systems. Further research is needed on this subject of treatment failure, not only to understand if these results are reproducible but also, in a broader sense, helping to fill this gap in modern medicine guidelines.

Novel Non-Congeneric Derivatives of the Choline Kinase Alpha Inhibitor ICL-CCIC-0019.

Choline kinase alpha (CHKA) is a promising target for the development of cancer therapeutics. We have previously reported ICL-CCIC-0019, a potent CHKA inhibitor with high cellular activity but with some unfavorable pharmacological properties. In this work, we present an active analogue of ICL-CCIC-0019 bearing a piperazine handle (CK146) to facilitate further structural elaboration of the pharmacophore and thus improve the biological profile. Two different strategies were evaluated in this study: (1) a prodrug approach whereby selective CHKA inhibition could be achieved through modulating the activity of CK146, via the incorporation of an ε-(Ac) Lys motif, cleavable by elevated levels of histone deacetylase (HDAC) and cathepsin L (CTSL) in tumour cells; (2) a prostate-specific membrane antigen (PSMA) receptor targeted delivery strategy. Prodrug (CK145) and PSMA-targeted (CK147) derivatives were successfully synthesized and evaluated in vitro. While the exploitation of CK146 in those two strategies did not deliver the expected results, important and informative structure-activity relationships were observed and have been reported.

Cardiac rehabilitation in older patients: Indication or limitation?

OBJECTIVE: To assess the clinical impact of a cardiac rehabilitation program in an older population. METHODS: This is a retrospective analysis of 731 coronary patients who attended phase 2 of a cardiac rehabilitation program between January 2009 and December 2016. We compared the response to the program of older (≥65 years) and younger (<65 years) patients, analyzing changes in metabolic profile (including body mass index, waist circumference and lipid profile), exercise capacity, cardiac autonomic regulation parameters (such as chronotropic index and resting heart rate), and health-related quality of life scores. RESULTS: Older patients represented 15.9% of our cohort. They showed significant reductions in waist circumference (male patients: 98.0±7.9 cm vs. 95.9±7.9 cm, p<0.001; female patients: 90.5±11.4 cm vs. 87.2±11.7 cm, p<0.001), LDL cholesterol (102.5 [86.3-128.0] mg/dl vs. 65.0 [55.0-86.0] mg/dl, p<0.001) and triglycerides (115.0 [87.8-148.5] mg/dl vs. 97.0 [81.8-130.0] mg/dl, p<0.001). Post-training data also showed a noticeable improvement in older patients' exercise capacity (7.6±1.8 METs vs. 9.3±1.8 METs, p<0.001), along with a higher chronotropic index and lower resting heart rate. Additionally, health-related quality of life indices improved in older subjects. However, our overall analysis found no significant differences between the groups in changes of the studied parameters. CONCLUSION: Older coronary patients benefit from cardiac rehabilitation interventions, similarly to their younger counterparts. Greater involvement of elderly patients in cardiac rehabilitation is needed to fully realize the therapeutic and secondary preventive potential of such programs.

A kit-based aluminium-[18F]fluoride approach to radiolabelled microbubbles.

The production of 18F-labelled microbubbles (MBs) via the aluminium-[18F]fluoride ([18F]AlF) radiolabelling method and facile inverse-electron-demand Diels-Alder (IEDDA) 'click' chemistry is reported. An [18F]AlF-NODA-labelled tetrazine was synthesised in excellent radiochemical yield (>95% RCY) and efficiently conjugated to a trans-cyclooctene (TCO) functionalised phospholipid (40-50% RCY), which was incorporated into MBs (40-50% RCY). To demonstrate the potential of producing 18F-labelled MBs for clinical studies, we also describe a kit-based approach which is amenable for use in a hospital radiopharmacy setting.

Detecting hypoxia in vitro using 18F-pretargeted IEDDA "click" chemistry in live cells.

We have exemplified a pretargeted approach to interrogate hypoxia in live cells using radioactive bioorthogonal inverse electron demand Diels-Alder (IEDDA) "click" chemistry. Our novel 18F-tetrazine probe ([18F]FB-Tz) and 2-nitroimidazole-based TCO targeting molecule (8) showed statistically significant (P < 0.0001) uptake in hypoxic cells (ca. 90 %ID per mg) vs. normoxic cells (<10 %ID per mg) in a 60 min incubation of [18F]FB-Tz. This is the first time that an intracellularly targeted small-molecule for IEDDA "click" has been used in conjunction with a radioactive reporter molecule in live cells and may be a useful tool with far-reaching applicability for a variety of applications.

Radiolabelling an 18F biologic via facile IEDDA "click" chemistry on the GE FASTLab™ platform.

The use of biologics in positron emission tomography (PET) imaging is an important area of radiopharmaceutical development and new automated methods are required to facilitate their production. We report an automated radiosynthesis method to produce a radiolabelled biologic via facile inverse electron demand Diels-Alder (IEDDA) "click" chemistry on a single GE FASTLab™ cassette. We exemplified the method by producing a fluorine-18 radiolabelled interleukin-2 (IL2) radioconjugate from a trans-cyclooctene (TCO) modified IL2 precursor. The radioconjugate was produced using a fully automated radiosynthesis on a single FASTLab™ cassette in a decay-corrected radiochemical yield (RCY, d.c.) of 19.8 ± 2.6% in 110 min (from start of synthesis); the molar activity was 132.3 ± 14.6 GBq µmol-1. The in vitro uptake of [18F]TTCO-IL2 correlated with the differential receptor expression (CD25, CD122, CD132) in PC3, NK-92 and activated human PBMCs. The automated method may be adapted for the radiosynthesis of any TCO-modified protein via IEDDA chemistry.