Low Uptake Research Articles

Molecular imaging with 68Ga-PSMA PET/CT in high grade glioma: A biomarker for tumour neo-angiogenesis.

There are several promising radiotracers used for both staging and restaging of primary and recurrent brain tumours based on various mechanisms of tracer localization in tumour cells. 68Ga-PSMA PET has extremely low background uptake in normal brain tissue and consequently high tumour-to-brain ratio making it a promising imaging radiotracer for gliomas. 68Ga-PSMA demonstrates utility in evaluating high grade glioma during both initial workup or when suspecting recurrence. Herein the authors evaluate the role of this imaging modality and the potential future it holds in the management of high grade gliomas.

Differences of stomatal ozone uptake in leaves of mature trees and seedlings of Zelkova serrata

Ozone uptake through the stomata in tree leaves is an important process for improving air quality by urban trees. Stomatal conductance (gs) is a key determinant of stomatal ozone uptake. The parameterization of gs models for estimating stomatal ozone uptake of trees has mainly been carried out using gs data measured in seedling leaves although the leaf traits may differ between mature trees and seedlings. In the present study, we compared stomatal ozone uptake estimated by gs models parameterised with data from mature trees and seedlings of Zelkova serrata. We measured gs in leaves of mature trees and seedlings of Z. serrata using a leaf porometer for 3–4 growing seasons. The Jarvis-type gs model was parameterised with data from mature trees and seedlings, separately. The maximum gs, and the functions of the seedling gs estimation model regarding the response to air temperature, vapour pressure deficit and atmospheric ozone concentration were the factors inducing lower stomatal ozone uptake. In contrast, the function of the seedling gs estimation model regarding the response to irradiance resulted in a higher estimated stomatal ozone uptake. The estimated stomatal ozone uptake for one growing season (April–September) by the seedling gs estimation model was 27% lower than that by the mature tree gs estimation model. These results indicate that leaf gas exchange traits of Z. serrata were different between mature trees and seedlings, and that estimating ozone uptake in mature tree leaves using a model based on seedling gs measurements results in an underestimation.

Adolescent girls' perceptions regarding the use of contraceptives in Ekurhuleni District, Gauteng.

Unintended pregnancies pose various challenges for adolescent girls and can be prevented through contraceptive use. However, contraceptive use among adolescents is lower compared to among older women. To describe adolescent girls' perceptions of the use of contraceptives. Two high schools in Tembisa were selected as the study setting. Purposive sampling was used to select adolescent girls who had reached menarche and were willing to participate. Data collection involved narrative writing for girls under 16 and interviews for older adolescents. Braun and Clark's six-step method was used for data analysis. A total of 35 adolescent girls were identified, and the final sample size was N = 33 adolescent girls whose ages ranged from 13 to 18 years. Two main themes emerged. Theme 1 was positive perceptions of contraceptives. Theme 1 was supported by two subthemes: the first was the influence of the male partner; the second was financial constraints in families. The second theme was negative perceptions of contraceptives. Four subthemes supported the second main theme, which were: myths and misconceptions, influence of parents, healthcare worker attitudes and negative attitudes of community members. Addressing the low contraceptive uptake among adolescent girls requires understanding their perceptions to tailor interventions accordingly. The study contributes by highlighting the negative perceptions of contraceptive use, including family financial constraints and the influence of male partners. These findings can inform reproductive health initiatives aimed at increasing contraceptive use among adolescents.

Nanoparticles in liposomes: a platform for increased antibiotic selectivity in multidrug resistant bacteria in respiratory tract infections.

Antibiotic resistance is a cause of serious illness and death, originating often from insufficient permeability into gram-negative bacteria. Nanoparticles (NP) can increase antibiotic delivery in bacterial cells, however, may as well increase internalization in mammalian cells and toxicity. In this work, NP in liposome (NP-Lip) formulations were used to enhance the selectivity of the antibiotics (3C and tobramycin) and quorum sensing inhibitor (HIPS-1635) towards Pseudomonas aeruginosa by fusing with bacterial outer membranes and reducing uptake in mammalian cells due to their larger size. Poly (lactic-co-glycolic) acid NPs were prepared using emulsion solvent evaporation and incorporated in larger liposomes. Cytotoxicity and uptake studies were conducted on two lung cell lines, Calu-3 and H460. NP-Lip showed lower toxicity and uptake in both cell lines. Then formulations were investigated for suitability for oral inhalation. The deposition of NP and NP-Lip in the lungs was assessed by next generation impactor and corresponded to 75% and 45% deposition in the terminal bronchi and the alveoli respectively. Colloidal stability and mucus-interaction studies were conducted. NP-Lip showed higher diffusion through mucus compared to NPs with the use of nanoparticle tracking analyzer. Moreover, the permeation of delivery systems across a liquid-liquid interface epithelial barrier model of Calu-3 cells indicated that NP-Lip could cause less systemic toxicity upon in-vivo like administration by aerosol deposition. Monoculture and Pseudomonas aeruginosa biofilm with Calu-3 cells co-culture experiments were conducted, NP-Lip achieved highest toxicity towards bacterial biofilms and least toxicity % of the Calu-3 cells. Therefore, the NP- liposomal platform offers a promising approach for enhancing antibiotic selectivity and treating pulmonary infections.

Synthesis and evaluation of bifunctional DFO2K: a modular chelator with ideal properties for zirconium-89 chelation.

The synthesis and evaluation of the newest generation of our DFO2 chelator family-DFO2K-is described. DFO2K was designed with a simple synthetic route to access different bifunctional derivatives, with each derivative having similar metal ion coordination spheres and high denticity (up to 12 coordinate) to ensure stable coordination of zirconium-89. The high denticity could potentially enhance stability with other large oxophilic radiometals. Zirconium-89 is the most popular radionuclide to pair with large macromolecules such as antibodies (immunoPET) for positron emission tomography applications. Although clinically successful, the stability of the "gold standard" chelator desferrioxamine B (DFO) can be improved as significant bone uptake is observed in animal models, despite no obvious stability issues in humans. Following the synthesis of DFO2K we assessed its radiolabeling efficiency with zirconium-89 and compared with DFO, which revealed rapid and nearly identical radiolabeling kinetics to DFO. The resultant [89Zr]Zr-DFO2K complex showed improved stability over [89Zr]Zr-DFO in different in vitro stability assays such as hydroxyapatite and 1000-fold molar excess EDTA challenges. Furthermore, biodistribution studies of the non-bifunctional chelators in healthy mice showed that [89Zr]Zr-DFO2K had a similar distribution profile and clearance to [89Zr]Zr-DFO. The bifunctional derivative p-SCN-Ph-DFO2K was conjugated to a non-specific human IgG antibody and evaluated after 2 weeks circulating in healthy female CD1 mice. Mice administered [89Zr]Zr-DFO2K-IgG showed substantially lower bone uptake in PET-CT images than [89Zr]Zr-DFO-IgG, with PET ROI data and ex vivo biodistribution revealing a statistically significantly lower bone uptake for DFO2K. Overall, owing to its high denticity, ease of synthesis, improved solubility over DFO2 and DFO2p, and stable chelation of zirconium-89, DFO2K appears to be an improved alternative chelator to DFO for zirconium-89 chelation.

COVID-19 Vaccine Risk Perception and Associated Vaccine Hesitancy Among HIV-Infected People at Parirenyatwa Centre of Excellence

<i>Background:</i> The impact of COVID-19 on people living with HIV (PLWH) is particularly concerning due to their existing health vulnerabilities. The low uptake of the COVID-19 vaccine and the failure to achieve herd immunity highlight the need to address vaccine hesitancy, especially in developing countries battling multiple infectious diseases. <i>Objective:</i> This study aimed to determine the relationship between COVID-19 vaccine risk perception and vaccine hesitancy among PLWH. <i>Materials and Methods:</i> An analytical cross-sectional design was used, involving 348 participants from Parirenyatwa Centre of Excellence, recruited via systematic random sampling. Data collection, following ethical approval, was conducted using a self-administered questionnaire. The data were categorized into structure, process, and outcome, and analyzed with SPSS version 22. <i>Results:</i> The study found that 79.9% of PLWH perceived a risk in taking the COVID-19 vaccine. About 55% had moderate knowledge of COVID-19, and 48.4% of those vaccinated had completed the vaccine course, with 43.2% receiving two doses and 7.2% only one dose. Motivations for vaccination included accessing services, travel compliance, work allowances, and entry permissions. Vaccine hesitancy was evident in 56% of participants, who were also unlikely to recommend vaccination to others. A positive correlation (r=0.159, p<0.03) was observed between vaccine risk perception and hesitancy. Barriers included fear of long waits, vaccine safety concerns, and insufficient information. <i>Conclusions:</i> The study demonstrated a significant positive correlation between vaccine risk perception and hesitancy among PLWH. It underscores the necessity of tailored vaccination messages addressing the specific concerns of PLWH and the need for increased governmental investment in awareness campaigns to achieve 75% herd immunity.

Effectiveness of a culturally tailored HIV intervention in promoting PrEP among black women who use drugs in community supervision programs in New York City: a randomized clinical trial

BackgroundIn the U.S. there are significant racial and gender disparities in the uptake of pre-exposure prophylaxis (PrEP). Black Americans represented 14% of PrEP users in 2022, but accounted for 42% of new HIV diagnoses in 2021 and in the South, Black people represented 48% of new HIV diagnoses in 2021 but only 21% of PrEP users in 2022. Women who use drugs may be even less likely than women who do not use drugs have initiated PrEP. Moreover, women involved in community supervision programs (CSP) are less likely to initiate or use PrEP, More PrEP interventions that focus on Black women with recent history of drug use in CSPs are needed to reduce inequities in PrEP uptake.MethodsWe conducted a secondary analysis from a randomized clinical trial with a sub-sample (n = 336) of the total (N = 352) participants from the parent study (E-WORTH), who tested HIV negative at baseline were considered PrEP-eligible. Black women were recruited from CSPs in New York City (NYC), with recent substance use. Participants were randomized to either E-WORTH (n = 172) an HIV testing plus, receive a 5-session, culturally-tailored, group-based HIV prevention intervention, versus an HIV testing control group (n = 180). The 5 sessions included an introduction to PrEP and access. This paper reports outcomes on improved awareness of PrEP, willingness to use PrEP, and PrEP uptake over the 12-month follow-up period. HIV outcomes are reported in a previous paper.ResultsCompared to control participants, participants in this study assigned to E-WORTH had significantly greater odds of being aware of PrEP as a biomedical HIV prevention strategy (OR = 3.25, 95% CI = 1.64–6.46, p = 0.001), and indicated a greater willingness to use PrEP as an HIV prevention method (b = 0.19, 95% CI = 0.06–0.32, p = 0.004) over the entire 12-month follow-up period.ConclusionsThese findings underscore the effectiveness of a culturally-tailored intervention for Black women in CSP settings in increasing awareness, and intention to initiate PrEP. Low uptake of PrEP in both arms highlight the need for providing more robust PrEP-on-demand strategies that are integrated into other services such as substance abuse treatment.Trial RegistrationClinicalTrials.gov Identifier: NCT02391233.

Factors Influencing the Use of Property Titles as Security for Lending in Rural Kenya: A Case Study of Kivani Location, Machakos County

The development of the world's economies, especially in emerging countries, depends significantly on land. Despite being a crucial tool for obtaining loans, the use of land as collateral is relatively low in rural Kenya. This has largely been attributed to lack of formal ownership documents attributable to poor titling, which has subsequently hindered investments and development in these areas. The research gap, therefore, lies in the need to understand and address the reasons behind the low uptake of land as collateral in rural Kenya, despite its potential as a valuable asset and its significant role in rural livelihoods and development. This study set out to establish factors influencing the use of property titles as loan security in a rural setting using Machakos County as a case study. Employing a descriptive research design, the study targeted 724 households in Kivani and 30 financial institution officers. Data was collected using questionnaires and topical discussions, achieving response rates of 96% and 100%, respectively. Findings reveal that 67 percent of respondents have never used land titles as collateral. Several factors were identified: social relations, lending conditions, and loan pricing. Social relations factors included communal land ownership, land succession problems, cultural norms, and sentimental attachment to land. Lending conditions encompassed land valuation processes, borrower creditworthiness requirements, collateral quality, and the need for family consent. Loan pricing factors involve the costs and fees associated with credit financing. The study recommends increasing awareness of individual land ownership, exploring alternative collateral options, establishing insurance markets for collateral assets, and improving loan evaluation processes to better support rural residents. These measures aim to enhance access to financing, thereby promoting rural development

Self-Collection for HPV Testing: Potential Issues Related to Performance Measures and Quality Improvement Among Federally Qualified Health Centers.

Most incident cases of cervical cancer in the United States are attributable to inadequate screening. Federally qualified health centers (FQHCs) serve a large proportion of women who are low-income, have no insurance, and are underserved-risk factors for insufficient cervical cancer screening. FQHCs must maintain quality measures to preserve their accreditation, address financial reimbursements, and provide quality care. Implementation of human papillomavirus (HPV) self-collection can improve cervical cancer screening coverage within FQHCs. To understand perspectives from clinical personnel on current cervical cancer screening rates at FQHCs in North Carolina and the impact of implementing HPV self-collection among underscreened patients on screening rates and performance measures. The study used focus groups and key informant interviews. Coding-based thematic analysis was applied to both focus group and interview transcripts. Emergent themes regarding perspectives on self-collection implementation were mapped onto Consolidated Framework for Implementation Research (CFIR) constructs to identify future barriers and facilitators to implementation. Two FQHCs in North Carolina and a cloud-based videoconferencing platform. Six FQHCs in North Carolina; 45 clinical and administrative staff from the 6 FQHCs; 1 chief executive officer (n = 6), 1 senior-level administrator (n = 6), 1 chief medical officer (n = 6), and 1 clinical data manager (n = 6) from each FQHC. Achievement of clinical perspectives. Societal-, practice-, and patient-level factors currently contribute to subpar cervical cancer screening rates. HPV self-collection was expected to improve screening uptake among underscreened women at FQHCs, and thus quality and performance measures, by offering an alternative screening approach for in-clinic or at-home use. Implementation barriers include financial uncertainties and HPV self-collection not yet a Food and Drug Administration-approved test. HPV self-collection has potential to improve cervical cancer screening quality and performance measures of FQHCs. For a successful implementation, multilevel factors that are currently affecting low screening uptake need to be addressed. Furthermore, the financial implications of implementation and approval of HPV self-collection as a test for cervical cancer screening quality measures need to be resolved.

18F-FDG whole-body PET/CT for the evaluation of suspected native valve infective endocarditis

18F-FDG-PET/CT is indicated in the workup of patients with suspected infective endocarditis to detect intra-cardiac and disseminated infections, as well as its source. We present the case of a 66-year-old female patient known for recurrent diabetic foot infection, with equivocal TTE results and persistent MRSA bacteremia despite medical management. PET/CT revealed evidence of left foot osteomyelitis. Whole body PET/CT diagnosed native mitral valve infective endocarditis (IE) and right lower lobe segmental pulmonary artery uptake, consistent with septic pulmonary embolism (PE).

ALDH5A1/miR-210 axis plays a key role in reprogramming cellular metabolism and has a significant correlation with glioblastoma patient survival

BackgroundGlioblastoma (GBM) is the most aggressive among the tumors of the central nervous system (CNS), and has a dismal prognosis. Altered metabolism, especially the increased rate of aerobic glycolysis promotes rapid proliferation of GBM cells. Here, we investigated the role of aldehyde dehydrogenase 5 family member A1 (ALDH5A1), a mitochondrial enzyme in the aspect of GBM metabolism. We also studied the regulatory mechanisms of altered ALDH5A1 expression in GBM.Approach and resultsWe show that ALDH5A1 is significantly downregulated in GBM patients in a grade dependent manner as compared to control brain and its low expression is associated with poor prognosis. It is significantly downregulated under hypoxia and is a direct target of the hypoxia induced microRNA: miR-210. Ectopic overexpression of ALDH5A1 in GBM cell lines U-87 MG and T98G markedly reduced their proliferation, 3D spheroid forming ability, and formation of reactive oxygen species (ROS). ALDH5A1 upregulation increased the oxygen consumption rate (OCR), and reduced the extracellular acidification rate (ECAR) of GBM cells while miR-210 overexpression showed the opposite. A significant downregulation in the transcript levels of LDHA, PDK1, and SLC2A1; coupled with lower glucose uptake and lactate production upon ALDH5A1 overexpression reveals that ALDH5A1 significantly reduces the glycolytic capacity of GBM cells. Total ATP generated in 24 h was more when miR-210 was overexpressed, while a slight decrease in ATP formation was observed upon ALDH5A1 upregulation. Interestingly, we also observed that ALDH5A1 expression is elevated and miR-210 levels are downregulated in IDH-mutant glioma as compared to its wild-type form.ConclusionOverall, our findings suggest that miR-210 mediated downregulation of ALDH5A1 plays a critical role in tumor metabolism and helps maintaining a high glycolytic phenotype in GBM.

Hormone therapy is associated with lower Alzheimer’s disease tau biomarkers in post-menopausal females -evidence from two independent cohorts

BackgroundFemales represent approximately 70% of the Alzheimer’s disease (AD) cases and the literature has proposed a connection between the decreased estrogen levels during menopause and an increased AD risk. Previous investigations have predominantly focused on assessing how hormone therapy (HT) affects the likelihood of AD development and cognitive deterioration. However, as the research framework has shifted toward a biomarker-defined AD and alterations in specific biomarkers could take place years before cognitive decline becomes discernible, it is crucial to examine how HT influences AD biomarkers. The main goal of this study was to evaluate the impact of HT on AD biomarker-informed pathophysiology in both cognitively unimpaired (CU) and cognitively impaired (CI) post-menopausal females across the aging and AD spectrum.MethodsThis cross-sectional study included post-menopausal females without HT history (HT-) and with HT (HT+) at the time of PET imaging assessment from two cohorts: the Translational Biomarkers in Aging and Dementia (TRIAD) cohort, and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Participants underwent magnetic resonance imaging (MRI), positron emission tomography (PET) and biofluid collection. Voxel-based t-tests were performed to assess the differences in amyloid-β (Aβ) and tau neurofibrillary tangles (NFTs) loads between HT- and HT + females. Linear regression models with interaction terms were also conducted to examine the interactive effects of HT and Aβ-PET on regional tau-PET.ResultsHT + females demonstrated significantly lower tau-PET standardized uptake value ratio (SUVR) in Braak I-II ROIs (P < 0.05, Hedges’ g = 0.73), Braak III-IV ROIs (P < 0.0001, Hedges’ g = 0.74) and Braak V-VI ROIs (P < 0.0001, Hedges’ g = 0.69) compared to HT- females. HT + females also showed significantly lower CSF p-tau181 (P < 0.001) and plasma p-tau181 (P < 0.0001) concentrations. Additionally, results from multivariate linear regression models indicated that HT interacts with cortical Aβ and is associated with lower regional NFT load.ConclusionsOverall, findings from this observational study suggest that HT is associated with lower tau neuroimaging and fluid biomarkers in postmenopausal females. Due to the close link between tau and cognition, this study highlights the need for large randomized controlled trials designed to systemically study the influences of HT on AD biomarkers and disease progression.

Association between striatal amyloid deposition and motor prognosis in Parkinson's disease.

The co-occurrence of amyloid-β pathology in Parkinson's disease (PD) is common; however, the role of amyloid-β deposition in motor prognosis remains elusive. This study aimed to investigate the association between striatal amyloid deposition, motor complications and motor prognosis in patients with PD. Ninety-six patients with PD who underwent 18F florbetaben (FBB) positron emission tomography were retrospectively assessed. The ratio of the striatum to global (STG) FBB uptake was obtained for each individual, and patients were allotted into low and high STG groups according to the median value. The effect of STG group on regional amyloid deposition, the occurrence of motor complications and longitudinal change in levodopa equivalent dose (LED) requirement were investigated after controlling for age, sex, LED and disease duration at FBB scan. The high STG group was associated with lower cortical FBB uptake in the parietal, occipital and posterior cingulate cortices and higher striatal FBB uptake compared to the low STG group. Patients in the high STG group had a higher risk of developing wearing off and levodopa-induced dyskinesia than those in the low STG group, whereas the risk for freezing of gait was comparable between the two groups. The high STG group showed a more rapid increase in LED requirements over time than the low STG group. These findings suggest that relatively high striatal amyloid deposition is associated with poor motor outcomes in patients with PD.

Associations of mothers’ decisional conflicts and satisfaction with governmental health promotion materials with their daughters’ HPV vaccination uptake in China: A cross-sectional survey

BackgroundChina started to implement the HPV vaccination program for females in 2016. This study investigated associations between mothers’ decisional conflicts, satisfaction with governmental health promotion materials, and their daughters’ HPV vaccination uptake. MethodsA cross-sectional online survey was conducted between July and October 2023 among mothers of girls aged 9–17 years in Shenzhen, China. Participants were mothers having a daughter aged 9–17 years at the survey date and a smartphone with internet access. About 3 % of all primary and secondary schools in Shenzhen were randomly selected by the research team (11 primary schools and 13 secondary schools). Teachers at the selected schools invited mothers of female students aged 9–17 years to complete an anonymous online questionnaire. Multivariate logistic regression was fitted. ResultsAmong 11,728 mothers who completed the survey, 18.9% of their index daughters received at least one dose of HPV vaccination. In multivariate analysis, less decisional conflict about the choice of HPV vaccines for their daughters (AOR: 1.07, 95%CI: 1.05, 1.10), more satisfaction with the government’s health promotional materials related to HPV vaccines (AOR: 1.15, 95%CI: 1.12, 1.19), receiving more cue to action from significant others (AOR: 1.23, 95%CI: 1.19, 1.27), and perceived higher self-efficacy related to HPV vaccines (AOR: 1.79, 95%CI: 1.67, 1.92) were associated with a higher uptake of HPV vaccines. Perceived susceptibility to HPV (AOR: 0.79, 95%CI: 0.74, 0.85), perceived barriers to having the index daughter receive HPV vaccines (AOR: 0.82, 95%CI: 0.80, 0.84), and mothers who were hesitant to receive HPV vaccination (AOR: 0.75, 95%CI: 0.68, 0.84) were associated with a lower uptake. ConclusionHPV vaccination uptake was low among girls in China. Future health promotion should address mothers’ decisional conflicts about the choice of HPV vaccines for their daughters and improve the health promotional materials. School-based HPV vaccination programs might be useful.

Diagnosis, treatment and burden in advanced ovarian cancer: a UK real-world survey of healthcare professionals and patients.

Aim: Little is known regarding uptake of epithelial ovarian cancer (EOC) treatments or patient burden in UK real-world practice.Methods: Cross-sectional surveys of patients with advanced EOC and healthcare professionals (HCPs).Results: 101 HCPs and 142 patients participated. Time from initial primary care consultation to diagnosis was ∼7weeks. 83% patients were offered hereditary genetic testing, with 89% uptake. 53% HCPs reported surgery was performed ≤1month in non-neoadjuvant setting. Surgery delay negatively impacted patient quality of life(61%), mental health (89%), and surgical outcomes (63%). 56% patients received active first-line maintenance treatment; patients on active surveillance had greater emotional/psychological distress.Conclusion: Treatment delays and low uptake of active first-line treatment should be addressed. Emotional support must be readily accessible throughout treatment.

Enhanced Oral Pre-exposure Prophylaxis (PrEP) Implementation for Ugandan Fisherfolk: Pilot Intervention Outcomes

Mobile populations such as fisherfolk show high HIV incidence and prevalence. We pilot-tested implementation strategies to enhance pre-exposure prophylaxis (PrEP) uptake and adherence in the context of healthcare outreach events in two mainland fisherfolk communities on Lake Victoria, Uganda from September 2021 to February 2022. The implementation strategies included PrEP adherence supporters (selected from PrEP users’ social networks), community workshops (to address misconceptions and stigma, and empower PrEP advocacy), and check-in calls (including refill reminders). PrEP medical records data were collected from 6-months pre-intervention to 6-months post-intervention. Qualitative interviews with 20 PrEP users (10 who continued, 10 who discontinued), 9 adherence supporters, and 7 key partners (providers, community leaders) explored acceptability. Percentages of PrEP initiators (of those eligible) were significantly higher during the intervention (96.5%) than 6-months before the intervention (84.5%), p < 0.0001; percentages of PrEP users who persisted (i.e., possessed a refill) 6-months post-initiation (47.9% vs. 6.7%) and had at least 80% PrEP coverage (based on their medication possession ratio) from the initiation date to 6-months later (35.9% vs. 0%) were higher during versus pre-intervention, p < 0.0001. A comparison fisherfolk community with better healthcare access had lower uptake (78.3%; p < 0.0001) and persistence at 6-months (34.0%; p < 0.001), but higher coverage during the intervention period (70.4%; p < 0.0001). Qualitative data suggested the strategies promoted PrEP use through reduced stigma and misconceptions. The intervention bundle cost was $223.95, $172.98, and $94.66 for each additional person for PrEP initiation, persistence, and coverage, respectively. Enhanced community-based PrEP implementation that fosters a supportive community environment can improve PrEP use in mobile populations without easy access to healthcare. (NCT05084716).

Current status of implementation of trauma registries' in LMICs & facilitators to implementation barriers: A literature review & consultation.

Background & objectives Many low- and middle- income countries (LMICs) have attempted to implement trauma registries with varying degrees of success. This study aimed to understand the registry implementation mechanism in LMICs better. Study objectives include assessment of the current use of trauma registries in LMICs, identification of barriers to the process and potential areas for intervention, and investigation of the registry implementation experience of key stakeholders in LMICs. Methods An initial narrative review of articles on trauma registry use in LMICs published in English between January 2017 and September 2023 was conducted. Key findings identified in this review were used to establish a theoretical framework from which an interview guide was subsequently developed. Expert consultation with key stakeholders in trauma registry implementation in two LMICs was conducted to assess the experience of registry implementation further. Results The presence of trauma registries in LMICs is limited. Key implementation barriers include funding concerns, uncoordinated administrative efforts, lack of human and physical resources (i.e., technology, equipment), and challenges in data management, analysis, and quality. Stakeholder interviews highlighted the importance of trauma registry development but echoed some obstacles, notably funding and data collection barriers. Interpretation & conclusions Barriers to registry implementation are ubiquitous and may contribute to the low uptake of registries in LMICs. One potential solution to these challenges is the application of the WHO International Registry for Trauma and Emergency Care. Future studies examining context-specific challenges to registry implementation and sustained utilization are required.

Histomolecular Validation of [18F]-FACBC in Gliomas Using Image-Localized Biopsies.

Gliomas have a heterogeneous nature, and identifying the most aggressive parts of the tumor and defining tumor borders are important for histomolecular diagnosis, surgical resection, and radiation therapy planning. This study evaluated [18F]-FACBC PET for glioma tissue classification. Pre-surgical [18F]-FACBC PET/MR images were used during surgery and image-localized biopsy sampling in patients with high- and low-grade glioma. TBR was compared to histomolecular results to determine optimal threshold values, sensitivity, specificity, and AUC values for the classification of tumor tissue. Additionally, PET volumes were determined in patients with glioblastoma based on the optimal threshold. [18F]-FACBC PET volumes and diagnostic accuracy were compared to ce-T1 MRI. In total, 48 biopsies from 17 patients were analyzed. [18F]-FACBC had low uptake in non-glioblastoma tumors, but overall higher sensitivity and specificity for the classification of tumor tissue (0.63 and 0.57) than ce-T1 MRI (0.24 and 0.43). Additionally, [18F]-FACBC TBR was an excellent classifier for IDH1-wildtype tumor tissue (AUC: 0.83, 95% CI: 0.71-0.96). In glioblastoma patients, PET tumor volumes were on average eight times larger than ce-T1 MRI volumes and included 87.5% of tumor-positive biopsies compared to 31.5% for ce-T1 MRI. The addition of [18F]-FACBC PET to conventional MRI could improve tumor classification and volume delineation.

61Cu-PSMA-Targeted PET for Prostate Cancer: From Radiotracer Development to First-in-Human Imaging.

The demand for PET tracers that target prostate-specific membrane antigen (PSMA) continues to increase. Meeting this demand with approved 68Ga- and 18F-labeled PSMA tracers is challenging outside of major urban centers. This is because the short physical half-life of these radionuclides makes it necessary to produce them near their sites of usage. To overcome this challenge, we propose cyclotron-produced 61Cu for labeling PSMA PET tracers. 61Cu can be produced on a large scale, and its 3.33-h half-life allows shipping over considerably longer distances than possible for 68Ga and 18F. Production of true theranostic twins using 61Cu and the β--emitter 67Cu is also feasible. Methods: PSMA-I&T (DOTAGA-(l-y)fk(sub-KuE)) and its derivative in which the DOTAGA chelator was replaced by NODAGA (NODAGA-(l-y)fk(sub-KuE)), herein reported as DOTAGA-PSMA-I&T and NODAGA-PSMA-I&T, respectively, were labeled with 61Cu and compared with [68Ga]Ga-DOTAGA-PSMA-I&T, [68Ga]Ga-NODAGA-PSMA-I&T, [68Ga]Ga-PSMA-11, and [18F]PSMA-1007. In vitro (lipophilicity, affinity, cellular uptake, and distribution) and invivo (PET/CT, biodistribution, and stability) studies were performed in LNCaP cells and xenografts. Human dosimetry estimates were calculated for [61Cu]Cu-NODAGA-PSMA-I&T. First-in-human imaging with [61Cu]Cu-NODAGA-PSMA-I&T was performed in a patient with metastatic prostate cancer. Results: [61Cu]Cu-DOTAGA-PSMA-I&T and [61Cu]Cu-NODAGA-PSMA-I&T were synthesized with radiochemical purity of more than 97%, at an apparent molar activity of 24 MBq/nmol, without purification after labeling. In vitro, natural Cu (natCu)-DOTAGA-PSMA-I&T and natCu-NODAGA-PSMA-I&T showed high affinity for PSMA (inhibitory concentration of 50%, 11.2 ± 2.3 and 9.3 ± 1.8 nM, respectively), although lower than the reference natGa-PSMA-11 (inhibitory concentration of 50%, 2.4 ± 0.4 nM). Their cellular uptake and distribution were comparable to those of [68Ga]Ga-PSMA-11. In vivo, [61Cu]Cu-NODAGA-PSMA-I&T showed significantly lower uptake in nontargeted tissues than [61Cu]Cu-DOTAGA-PSMA-I&T and higher tumor uptake (14.0 ± 5.0 percentage injected activity per gram of tissue [%IA/g]) than [61Cu]Cu-DOTAGA-PSMA-I&T (6.06 ± 0.25 %IA/g, P = 0.0059), [68Ga]Ga-PSMA-11 (10.2 ± 1.5 %IA/g, P = 0.0972), and [18F]PSMA-1007 (9.70 ± 2.57 %IA/g, P = 0.080) at 1 h after injection. Tumor uptake was also higher for [61Cu]Cu-NODAGA-PSMA-I&T at 4 h after injection (10.7 ± 3.3 %IA/g) than for [61Cu]Cu-DOTAGA-PSMA-I&T (4.88 ± 0.63 %IA/g, P = 0.0014) and [18F]PSMA-1007 (6.28 ± 2.19 %IA/g, P = 0.0145). Tumor-to-nontumor ratios of [61Cu]Cu-NODAGA-PSMA-I&T were superior to those of [61Cu]Cu-DOTAGA-PSMA-I&T and comparable to those of [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 at 1 h after injection and increased significantly between 1 and 4 h after injection in most cases. Human dosimetry estimates for [61Cu]Cu-NODAGA-PSMA-I&T were similar to the ones reported for 18F-PSMA ligands. First-in-human imaging demonstrated multifocal osseous and hepatic metastases. Conclusion: [61Cu]Cu-NODAGA-PSMA-I&T is a promising PSMA radiotracer that compares favorably with [68Ga]Ga-PSMA-11 and [18F]PSMA-1007, while allowing delayed imaging.

Combining [177Lu]Lu-DOTA-TOC PRRT with PARP inhibitors to enhance treatment efficacy in small cell lung cancer.

Small cell lung cancer (SCLC) is a highly aggressive tumor with neuroendocrine origin. Although SCLC frequently express somatostatin receptor type 2 (SSTR2), a significant clinical benefit of SSTR2-targeted radionuclide therapies of SCLC was not observed so far. We hypothesize that combination treatment with a PARP inhibitor (PARPi) could lead to radiosensitization and increase the effectiveness of SSTR2-targeted therapy in SCLC. SSTR2-ligand uptake of the SCLC cell lines H69 and H446 was evaluated in vitro using flow cytometry, and in vivo using SPECT imaging and cut-and-count biodistribution. Single-agent (Olaparib, Rucaparib, [177Lu]Lu-DOTA-TOC) and combination treatment responses were determined in vitro via cell viability, clonogenic survival and γH2AX DNA damage assays. In vivo, we treated athymic nude mice bearing H69 or H446 xenografts with Olaparib, Rucaparib, or [177Lu]Lu-DOTA-TOC alone or with combination treatment regimens to assess the impact on tumor growth and survival of the treated mice. H446 and H69 cells exhibited low SSTR2 expression, i.e. 60 to 90% lower uptake of SSTR2-ligands compared to AR42J cells. In vitro, combination treatment of [177Lu]Lu-DOTA-TOC with PARPi resulted in 2.9- to 67-fold increased potency relative to [177Lu]Lu-DOTA-TOC alone. We observed decreased clonogenic survival and higher amounts of persistent DNA damage compared to single-agent treatment for both Olaparib and Rucaparib. In vivo, tumor doubling times increased to 1.6-fold (H446) and 2.2-fold (H69) under combination treatment, and 1.0 to 1.1-fold (H446) and 1.1 to 1.7-fold (H69) in monotherapies compared to untreated animals. Concurrently, median survival was higher in the combination treatment groups in both models compared to monotherapy and untreated mice. Fractionating the PRRT dose did not lead to further improvement of therapeutic outcome. The addition of PARPi can markedly improve the potency of SSTR2-targeted PRRT in SCLC models in SSTR2 low-expressing tumors. Further evaluation in humans seems justified based on the results as novel treatment options for SCLC are urgently needed.