Post Injection Research Articles

Optimization of an Allysine-Targeted PET Probe for Quantifying Fibrogenesis in a Mouse Model of Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a destructive lung disease with a poor prognosis, an unpredictable clinical course, and inadequate therapies. There are currently no measures of disease activity to guide clinicians making treatment decisions. The aim of this study was to develop a PET probe to identify lung fibrogenesis using a pre-clinical model of pulmonary fibrosis, with potential for translation into clinical use to predict disease progression and inform treatment decisions. Eight novel allysine-targeting chelators, PIF-1, PIF-2, …, PIF-8, with different aldehyde-reactive moieties were designed, synthesized, and radiolabeled with gallium-68 or copper-64. PET probe performance was assessed in C57BL/6J male mice 2 weeks after intratracheal bleomycin challenge and in naïve mice by dynamic PET/MR imaging and with biodistribution at 90 min post injection. Lung hydroxyproline and allysine were quantified ex vivo and histological staining for fibrosis and aldehyde was performed. In vivo screening of probes identified 68GaPIF-3 and 68GaPIF-7 as probes with high uptake in injured lung, high uptake in injured lung versus normal lung, and high uptake in injured lung versus adjacent liver and heart tissue. A crossover, intra-animal PET/MR imaging study of 68GaPIF-3 and 68GaPIF-7 confirmed 68GaPIF-7 as the superior probe. Specificity for fibrogenesis was confirmed in a crossover, intra-animal PET/MR imaging study with 68GaPIF-7 and a non-binding control compound, 68GaPIF-Ctrl. Substituting copper-64 for gallium-68 did not affect lung uptake or specificity indicating that either isotope could be used. A series of allysine-reactive PET probes with variations in the aldehyde-reactive moiety were evaluated in a pre-clinical model of lung fibrosis. The hydrazine-bearing probe, 68GaPIF-7, exhibited the highest uptake in fibrogenic lung, low uptake in surrounding liver or heart tissue, and low lung uptake in healthy mice and should be considered for further clinical translation.

103 Botulinum Toxin Type A (Botox) Injection for Plantar Fasciitis: An Audit of Findings

Abstract Introduction Plantar fasciitis is commonly seen in the musculoskeletal clinic and accounts for around 8-10% of running injuries. NICE recommended corticosteroid injections for patients whose “symptoms are having a significant impact on the person”, however, symptoms lasted for 4 weeks post injection. The use of Botox for the treatment of myofascial pain has increased, with studies showing greater reduction in patients symptoms and improved duration of action. Material and methods 42 patients (27 male, 15 female) were included in this audit. All patients received 100 units of botox. Inclusion/Exclusion criteria All patients who had clinically diagnosed plantar fasciitis and had received the first line treatments of stretching and orthotics. Patients yet to begin a stretching program or had systemic disease or previous surgery were excluded. Outcome measure A patient assessed (VAS) and a physician assessed (Heel Tenderness Index) outcome measure was used. Results 42 patients were assessed. VAS All the patients reported an improvement in symptoms at the 4 week follow up, 38 (90.48%) of whom reported pain free. Of the remaining 4 all advised their symptoms had improved by at least 50% HTI 38 (90.48%) had no pain on palpation of the heel post injection, whilst prior to the injection all patients had pain in differing degrees. 15 patients (35.71%) had severe pain prior to the injection, post injection no patient had severe pain. 40 (95.24%) patients had improved HTI scores. Conclusions Botox is effective in the treatment of plantar fasciitis, however, its effectiveness in the longer term needs to be assessed.

Diagnosis of pituitary abscess and treatment via transsphenoidal surgery: experience from 15 cases

ObjectivePituitary abscess is an often misdiagnosed, rare clinical disorder. To improve diagnostic accuracy and the efficacy of surgical and antibiotic therapy for patients with pituitary abscess, herein, we retrospectively reviewed 15 patients who presented with pituitary abscesses from 2005 to 2022. DesignRetrospective study. PatientsFifteen patients underwent transsphenoidal surgery and received antibiotic treatment. MeasurementsComplete details regarding medical history, clinical manifestations, laboratory examinations, imaging studies, and treatment strategies were obtained for all patients. ResultsMost patients presented with hypopituitarism and headaches, while some presented with fever, visual disturbances, and diabetes insipidus (DI). Abscesses showed significant annular enhancement post gadolinium injection. In most patients, pituitary abscess can be cured via microscopic or endoscopic drainage of the abscess followed by antibiotic treatment. Complete cure of pituitary abscess was observed in nine patients, with six cases of prolonged hypopituitarism and only one case of recurrence. Long-term hormone replacement therapy was effective in the postoperative management of hypopituitarism. ConclusionsThe typical manifestations of pituitary abscess include hypopituitarism and headaches; the presence of an enhanced ring at the edge of the mass on contrast-enhanced magnetic resonance images (MRI) is highly suggestive of pituitary abscess. We recommend antibiotic treatment for 4–6 weeks postoperatively, based on the results of bacterial cultures or metagenomic next-generation sequencing (mNGS).

Ultrasound-guided hepatic portal vein injection is not a reproducible technique for delivery of cell therapies to the liver in mice.

Our aim was to determine if ultrasound-guided HPV injection in mice would provide reproducible and reliable results, as is currently obtained via open laparotomy techniques, and offer a surgical refinement to emulate islet transplantation in humans. Fluorescent-polymer microparticles (20 μm) were injected (27G-needle) into the HPV via open laparotomy (n = 4) or under ultrasound-guidance (n = 4) using an MX550D-transducer with a Vevo3100-scanner (FUJIFILM VisualSonics, Inc.). Mice were culled 24-h post injection; organs were frozen, step sectioned (10 μm-slices) and 10 sections/mouse (50 μm-spacing) were quantified for microparticles in the liver and other organs by fluorescent microscopy. Murine HPV injection, via open laparotomy-route, resulted in widespread distribution of microparticles in the liver, lungs and spleen; ultrasound-guided injection resulted in reduced microparticle delivery (p < 0.0001) and microparticle clustering in distinct areas of the liver at the site of needle penetration, with very few/no microparticles being seen in lung and spleen tissues, hypothesised to be due to flow into the body cavity: liver median (interquartile range) 4.15 (0.00-4.15) versus 0.00 (0.00-0.00) particle-count mm-2 , respectively. Ultrasound-guided injection results in microparticle clustering in the liver, with an overall reduction in microparticle number when compared to open laparotomy HPV injection, and high variability in microparticle-counts detected between mice. Ultrasound-guided injection is not currently a technique that can replace open laparotomy HPV of islet transplantation in mice.

Long-Term Outcomes in Early versus Limited Response to Anti-VEGF Treatment for Retinal Vein Occlusion

Macular edema secondary to retinal vein occlusion (RVO) is a sight-threatening condition. Previous studies showed that early responders (ERs) who respond well to anti-VEGF injections within 3 months of treatment have better outcomes, as measured by best visual acuity (BVA) and central subfield thickness (CST) at 12 months postinjection initiation compared with limited early responders (LERs). This study analyzed whether ER eyes continue to respond better than LER eyes over longer periods. This study also aimed to identify baseline comorbidities associated with response status. Retrospective cohort study. Patients aged > 18 years with RVO-related macular edema treated with anti-VEGF injections. Patients were categorized as ERs or LERs. Limited early responder eyes were defined as having CST reduction < 10%, BVA gain < 5 ETDRS letters, or both at 3 months after anti-VEGF initiation. Best visual acuity and CST changes over the 24- and 36-month period after the first anti-VEGF treatment were compared between ERs and LERs. Patient characteristics and systemic comorbidities were identified by chart review. Statistical analysis involved the Levene test, Welch t test, and Welch analysis of variance. Best visual acuity and CST changes over the initial 24-month and 36-month periods after treatment. The 24-month cohort included 68 ERs and 39 LERs, and the 36-month cohort included 58 ERs and 33 LERs. At the 24-month time point, there were significant differences in BVA and CST gains between ERs (+19.8 letters,-221.2 um) and LERs (-2.4 letters,-90.1 um; P < 0.001, P < 0.01). Similarly, at 36 months, there were significant differences in BVA and CST gains between ERs (+17.7 letters,-229.3 um) and LERs (+1.3letters,-128 um; P < 0.001, P < 0.05). After controlling for differences in baseline BVA and CST, only the 24-month change in BVA remained significant (P < 0.001). There were no significant associations between response status and cardiopulmonary, endocrine, and oncologic comorbidities. Early responder eyes with branched retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) have better functional responses to anti-VEGF injections at 24 months compared with LER eyes, even after controlling for baseline differences. Early identification of eyes as ERs or LERs in BRVO and CRVO may predict long-term functional prognoses. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The interaction of placental micro-EVs with immune cells in vivo and in vitro.

Considerable evidence suggests that placental extracellular vesicles (EVs) interact with most types of leukocytes in vitro but in vivo biodistribution studies question whether these interactions are reflective of the situation in vivo. CellTracker Red CMTPX stained human placental micro-EVs were isolated from first trimester placental explant cultures. Equivalent amounts of micro-EVs were cultured with murine leukocytes in vitro or injected into pregnant or non-pregnant mice. After intravenous injection, on day 12.5 of gestation, major organs and blood samples were harvested 30 min or 24h post injection. We screened cryosections of the organs and confirmed that human placental EVs were specifically localised to the spleen, liver and the lungs 30 min or 24h after injection. Immunohistochemistry showed that most of the EVs interacted with macrophages in those three organs and some of them also associated with T and B lymphocytes in the spleen or endothelial cells in the lungs and liver. Flow cytometry demonstrated that there was very little interaction between circulating leukocytes and EVs in vivo. While minimal, significantly more EVs interacted with leukocytes in pregnant than nonpregnant mice. The major interaction between human placental micro-EVs and maternal leukocytes appear to be with macrophages predominantly in the splenic marginal zone, liver and lungs with little interaction between EVs and circulating leukocytes. Since marginal zone macrophages induce tolerance after phagocytosing apoptotic bodies it is likely that phagocytosis of placental EVs by marginal zone macrophages may also contribute to maternal immune tolerance.

AAV1.NT-3 gene therapy in the SOD1KO mouse model of accelerated sarcopenia.

Sarcopenia, an age-related loss of muscle mass, is a critical factor that affects the health of the older adults. The SOD1KO mouse is deficient of Cu/Zn superoxide dismutase, used as an accelerated aging model. We previously showed that NT-3 improves muscle fibre size by activating the mTOR pathway, suggesting a potential for attenuating age-related muscle loss. This study assessed the therapeutic efficacy of AAV1.NT-3 in this accelerated aging model. Twelve 6months old SOD1KO mice were injected intramuscularly with a 1×1011 vg dose of AAV1.tMCK.NT-3, and 13 age-matched SOD1KO mice were used as controls. The treatment effect was evaluated using treadmill, rotarod and gait analyses as well as histological studies assessing changes in muscle fibre, and fibre type switch, in tibialis anterior, gastrocnemius, and triceps muscles, and myelin thickness by calculating G ratio in sciatic and tibial nerves. Molecular studies involved qPCR experiments to analyse the expression levels of mitochondrial and glycolysis markers and western blot experiments to assess the activity of mTORC1 pathway. Treatment resulted in a 36% (154.9 vs. 114.1; P<0.0001) and 76% increase (154.3 vs. 87.6; P<0.0001) in meters ran, with treadmill test at 3 and 6months post gene delivery. In addition, the treated cohort stayed on rotarod 30% (52.7s vs. 40.4s; P=0.0095) and 54% (50.4s vs. 32.7s; P=0.0007) longer, compared with untreated counterparts at 3 and 6months post injection. Gait analysis, performed at endpoint, showed that stride width was normalized to wild type levels (29.3mm) by an 11% decrease, compared with untreated cohort (28.6mm vs. 32.1mm; P=0.0014). Compared with wild-type, SOD1KO mice showed 9.4% and 11.4% fibre size decrease in tibialis anterior and gastrocnemius muscles, respectively, which were normalized to wild type levels with treatment. Fibre diameter increase was observed prominently in FTG fibre type. G ratio analysis revealed hypomyelination in the tibial (0.721) and sciatic (0.676) nerves of SOD1KO model, which was reversed in the NT-3 cohort (0.646 and 0.634, respectively). Fibre size increase correlated with the increase in the p-S6 and p-4E-BP1 levels, and in the glycolysis markers in tibialis anterior. Alterations observed in the mitochondrial markers were not rescued with treatment. Overall, response to NT-3 was subdued in gastrocnemius muscle. This study shows that AAV1.NT-3 gene therapy protected SOD1KO mouse from accelerated aging effects functionally and histologically. We further confirmed that NT-3 has potential to activate the mTOR and glycolytic pathways in muscle.

Abstract P3059: Recombinant Adeno-associated Viral Vector 2/8 Model Of Interleukin 6 Mediated Chronic Inflammation

Background: Interleukin 6 (IL6) is a pleiotropic cytokine mostly known as a proinflammatory cytokine. There is a need for a reliable in vivo model to study IL6 mediated chronic inflammation. Hypothesis: The aim of our study was to create a mouse model mimicking the chronic inflammatory state as observed in cancer and inflammatory diseases. We opted for a recombinant adeno-associated viral vector (rAAV) to mimic the acute initiation of chronic inflammation later in life. Methods: We opted for a rAAV2/8 subtype, human EF1a short (EFS) promoter and firefly luciferase led by an internal ribosome entry site (IL6-IRES-fLuc) DNA cassette to create a stable low-grade expression of IL6 in liver and serum, with minimal expression in other organs, particularly the heart. rAAV2/8_EFS-IL6-IRES-fLuc and the control vector rAAV2/8_EFS-MCS-IRES-fLuc were generated and different dosages were tested. Results: All mice treated with high dose AAV2/8-IL6 vector (8.8* 10 10 genome copies (GC)/animal) showed severe weight loss and hepatosplenomegaly, starting between week 4-6 post injection. Histological examination of the liver showed features of chronic hepatitis. Infiltrating cells were found in both the liver and the heart. In the spleen, the histological structure of red and white pulp was disturbed and more giant cells could be detected. Cardiac function remained normal at 6 weeks post injection. Assuming that the previous results were due to an overexpression of IL6 due to too high amounts of rAAV2/8_EFS-IL6-IRES-fLuc, we subsequently challenged mice with a rAAV2/8_EFS-IL6-IRES-fLuc dilution series to test which vector dose could be used for reliable long-term low grade IL6 overexpression. After extensive testing, the ideal dose for a 12 weeks IL6 overexpression model was between 2.2 and 2.93* 10 10 GC. Using this dose range, we saw stable overexpression of IL6 without weight loss. Hepatosplenomegaly, disturbed anatomy of the spleen and infiltrating cells in the liver were still present yet less pronounced. Conclusion: We successfully generated and characterized a mouse model of IL6 overexpression to mimic chronic IL6 mediated inflammation. To the best of our knowledge this is the first model employing IL6 overexpression using a rAAV viral vector.

Near-infrared fluorescence cholangiography in dogs: A pilot study.

To determine the effect of indocyanine green (ICG) dose and timing of administration on near-infrared fluorescence (NIRF) imaging of the normal canine biliary tree. Preclinical prospective study. Eight purpose-bred beagles. The dogs were randomized to receive two of four intravenous ICG dose (low [L]:0.05 mg/kg or high [H]:0.25 mg/kg)/time (0 and 3 h prior to NIRF) combinations. NIRF images were collected every 10 min for 120 min. Target (cystic duct)-to-background (liver) ratios were calculated for all timepoints and compared. ICG cholangiography was successful in all dogs. The contrast ratio was above 1 in the L0 group by 20 min and reached its peak at 100 min. In the H0 group, the ratio was above 1 by 60 min and reached its peak at 90 min. Contrast ratios above 2 (fluorescence twice as bright in the cystic duct compared to the liver) were maintained from 180 to 300 min for L3 and H3 and was achieved after 80 min for L0. Low dose ICG provided better ratios early after injection compared to the high dose which remained highly concentrated in the liver tissue after injection. Both doses provided excellent visualization of the biliary tree at 3 h post injection, low dose ICG provided better ratios from 3 to 5 h post injection. Based on these results, 0.05 mg/kg of ICG administered at anesthetic premedication, or as early as 3 h prior to laparoscopic surgery should yield optimal fluorescence images. This study provides guidelines for NIRF cholangiography in clinically normal dogs.

Automated Synthesis and Preclinical Evaluation of Optimized Integrin α6-Targeted Positron Emission Tomography Imaging of Pancreatic Cancer.

Integrin α6 has been considered a promising biomarker, is overexpressed in many tumors, and plays a vital role in tumor formation, recurrence, and metastasis. In this study, we identified a novel high-affinity integrin α6-targeted peptide named RD2 (Arg-Trp-Tyr-Asp-PEG4)2-Lys-Lys and developed a 18F-radiolabeled peptide tracer ([18F]-AlF-NOTA-RD2) and evaluated its potential application in positron emission tomography (PET) imaging of pancreatic cancer. [18F]-AlF-NOTA-RD2 was produced using GMP (Good Manufacturing Practice of Medical Products)-compliant automatic radiosynthesis on a single GE FASTLab2 cassette-type synthesis module. The stability of [18F]-AlF-NOTA-RD2 was analyzed in phosphate-buffered saline (PBS) and fetal bovine serum (FBS). The cell uptake assay of the tracer was assessed using PANC-1 cells. In addition, small-animal PET imaging and biodistribution studies of [18F]-AlF-NOTA-RD2 were performed in pancreatic cancer subcutaneous tumor-bearing mice. The PET tracer [18F]-AlF-NOTA-RD2 was obtained with a radiochemical yield of 23.7 ± 4.7%, radiochemical purity of >99%, and molar activity of 165.7 ± 59.1 GBq/μmol. [18F]-AlF-NOTA-RD2 exhibited good in vitro stability in PBS and FBS. LogP octanol water value for the tracer was -2.28 ± 0.05 (n = 3). The binding affinity of RD2 to the integrin α6 protein (Kd = 0.13 ± 3.65 μM, n = 3) was significantly higher than that of the RWY (CRWYDENAC) (Kd = 6.97 ± 1.44 μM, n = 3). Small-animal PET imaging and biodistribution also revealed that [18F]-AlF-NOTA-RD2 displayed rapid and good tumor uptake and lower liver background uptake in PANC-1 tumor-bearing mice. [18F]-AlF-NOTA-RD2 showed significant radioactivity accumulation in tumors and was successfully blocked by NOTA-RD2. Compared with [18F]-FDG, [18F]-AlF-NOTA-RD2 PET imaging and biodistribution studies in PANC-1 xenograft tumor-bearing mice confirmed a good tumor-to-muscle ratio (8.69 ± 2.03 vs 1.41 ± 0.23, respectively) at 0.5 h and (2.99 ± 3.02 vs 1.43 ± 0.17, respectively) at 1 h post injection. Autoradiography of human pancreatic cancer tumor tissues further confirmed high accumulation of [18F]-AlF-NOTA-RD2. In summary, we developed an optimized integrin α6-targeted imaging tracer and obtained high radioactivity products with a cassette-type synthesis module; moreover, the tracer exhibited good binding affinity with integrin α6 and good target specificity for PANC-1 cells in xenograft pancreatic tumor-bearing mice, demonstrating its promising application as a noninvasive PET radiotracer of integrin α6 expression in pancreatic cancer.

Do age, gender, BMI and disease duration influence the clinical outcomes in patients of knee osteoarthritis treated with serial injections of autologous platelet rich plasma?

PurposeTo study whether age, gender, body mass index(BMI) and disease duration influence the clinical outcomes in kellgren-Lawrence(K-L) grade II,III knee osteoarthritis(KOA) patients treated with serial injections of platelet rich plasma(PRP). Patients and methods65 patients were given three monthly intra-articular injections of PRP in this prospective interventional study. The patients were divided into subgroups depending on the factor studied: by age(in years) into young <45(n = 7), middle age 45-60(n = 35), and elderly >60(n = 23): by BMI(in kg/m2) into; normal <25(n = 25), overweight 25-30(n = 27) and obese >30(n = 13) and disease duration; less(n = 32) or more than 1 year(n = 33) symptom duration. Visual analogue scale (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used as outcome measures and assessed before each injection and then at 6 and 9 months post injection. Groups were homogenous with respect to baseline characteristics. ResultsMean VAS and WOMAC scores showed a statistically significant improvement (P < 0.0001) across all groups and subgroups (age,gender,BMI,disease duration) at follow up. On intra-subgroup comparison, we found no significant differences(P > 0.05) among age, BMI or gender subgroups, however the scores were significantly better in patients with disease duration of less than 1 year than those with more than 1 year duration at both 6 and 9 months[P < 0.001(RC = 9.630,95% CI = 4.037–15.222,P = 0.001)]. ConclusionPRP injections if given serially can improve the short term subjective scores of VAS and WOMAC scores in patients with K-L grade II and III KOA irrespective of age, gender, BMI or disease duration, however, clinical benefits can be maximized if given early in the disease course.

Evaluation of nimotuzumab Fab2 as an optical imaging agent in EGFR positive cancers

Molecular-targeted imaging probes can be used with a variety of imaging modalities to detect diseased tissues and guide their removal. EGFR is a useful biomarker for a variety of cancers, because it is expressed at high levels relative to normal tissues. Previously, we showed the anti-EGFR antibody nimotuzumab can be used as a positron emission tomography and fluorescent imaging probe for EGFR positive cancers in mice. These imaging probes are currently in clinical trials for PET imaging and image-guided surgery, respectively. One issue with using antibody probes for imaging is their long circulation time and slow tissue penetration, which requires patients to wait a few days after injection before imaging or surgery, multiple visits and longer radiation exposure. Here, we generated a Fab2 fragment of nimotuzumab, by pepsin digestion and labeled it with IRDye800CW to evaluate its optical imaging properties. The Fab2 had faster tumor accumulation and clearance in mice relative to the nimotuzumab IgG. The fluorescent signal peaked at 2 h post injection and remained high until 6 h post injection. The properties of the Fab2 allow a higher signal to background to be obtained in a shorter time frame, reducing the wait time for imaging after probe infusion.

Poster 223: Patient Reported Outcomes Following Treatment with Leukocyte Rich Platelet Rich Plasma Injections for Proximal Hamstring Tendinopathy

Poster 223: Patient Reported Outcomes Following Treatment with Leukocyte Rich Platelet Rich Plasma Injections for Proximal Hamstring Tendinopathy

Skin testing: A valuable screening tool to identify allergy to anesthetic agents

Abstract Anaphylaxis is a rapid-onset, life-threatening allergic reaction that needs immediate medical intervention. Typically, immunoglobulin E (IgE) mediated, these reactions necessitate skin testing for assessing drug hypersensitivity. A 31-year-old woman with cervical carcinoma, scheduled for a total hysterectomy with bilateral salpingo-oophorectomy under general anesthesia (GA), experienced preoperative urticaria and palpitations, during a blood transfusion. Administering intravenous (IV) pheniramine, ranitidine, and dexamethasone resolved symptoms, allowing surgery under GA. However, post atracurium injection, she developed generalized urticaria and mild hypotension. IV pheniramine and hydrocortisone stabilized her, prompting surgery deferral for an allergology workup. The skin testing was performed, and all drugs tested negative. To prevent non-IgE-mediated reactions, a preoperative regimen of pheniramine 25 mg, prednisolone 50 mg, and famotidine 20 mg was recommended. Subsequently, surgery was performed under GA, using propofol and rocuronium, with the whole perioperative period remaining uneventful. This case underscores the imperative role of skin testing in elucidating perioperative drug usage amid suspected or encountered drug allergies.

Immuno-PET of colorectal cancer with a CEA-targeted [68Ga]Ga-nanobody: from bench to bedside.

An accurate diagnosis of colorectal carcinoma (CRC) can assist physicians in developing reasonable therapeutic regimens, thereby significantly improving the patient's prognosis. Carcinoembryonic antigen (CEA)-targeted PET imaging shows great potential for this purpose. Despite showing remarkable abilities to detect primary and metastatic CRC, previously reported CEA-specific antibody radiotracers or pretargeted imaging are not suitable for clinical use due to poor pharmacokinetics and complicated imaging procedures. In contrast, radiolabeled nanobodies exhibit ideal characteristics for PET imaging, for instance, rapid clearance rates and excellent distribution profiles, allowing same-day imaging with sufficient contrast. In this study, we developed a novel CEA-targeted nanobody radiotracer, [68Ga]Ga-HNI01, and assessed its tumor imaging ability and biodistribution profile in preclinical xenografts and patients with primary and metastatic CRC. The novel nanobody HNI01 was acquired by immunizing the llama with CEA proteins. [68Ga]Ga-HNI01 was synthesized by site-specifically conjugating [68Ga]Ga with tris(hydroxypyridinone) (THP). Small-animal PET imaging and biodistribution studies were performed in CEA-overexpressed LS174T and CEA-low-expressed HT-29 tumor models. Following successful preclinical assessment, a phase I study was conducted on 9 patients with primary and metastatic CRC. Study participants received 151.21 ± 25.25MBq of intravenous [68Ga]Ga-HNI01 and underwent PET/CT scans at 1h and 2h post injection. Patients 01-03 also underwent whole-body dynamic PET imaging within 0-40min p.i. All patients underwent [18F]F-FDG PET/CT imaging within 1week after [68Ga]Ga-HNI01 imaging. Tracer distribution, pharmacokinetics, and radiation dosimetry were calculated. [68Ga]Ga-HNI01 was successfully synthesized within 10min under mild conditions, and the radiochemical purity was more than 98% without purification. Micro-PET imaging with [68Ga]Ga-HNI01 revealed clear visualization of LS174T tumors, while signals from HT-29 tumors were significantly lower. Biodistribution studies indicated that uptake of [68Ga]Ga-HNI01 in LS174T and HT-29 was 8.83 ± 3.02%ID/g and 1.81 ± 0.87%ID/g, respectively, at 2h p.i. No adverse events occurred in all clinical participants after the injection of [68Ga]Ga-HNI01. A fast blood clearance and low background uptake were observed, and CRC lesions could be visualized with high contrast as early as 30min after injection. [68Ga]Ga-HNI01 PET could clearly detect metastatic lesions in the liver, lung, and pancreas and showed superior ability in detecting small metastases. A significant accumulation of radioactivity was observed in the kidney, and normal tissues physiologically expressing CEA receptors showed slight uptakes of [68Ga]Ga-HNI01. An interesting finding was that strong uptake of [68Ga]Ga-HNI01 was found in non-malignant colorectal tissues adjacent to the primary tumor in some patients, suggesting abnormal CEA expression in these healthy tissues. [68Ga]Ga-HNI01 is a novel CEA-targeted PET imaging radiotracer with excellent pharmacokinetics and favorable dosimetry profiles. [68Ga]Ga-HNI01 PET is an effective and convenient imaging tool for detecting CRC lesions, particularly for identifying small metastases. Furthermore, its high specificity for CEA in vivo makes it an ideal tool for selecting patients for anti-CEA therapy.

Short term effects of intraarticular triamcinolone acetonide injection on serum testosterone, luteinizing hormone, and follicle stimulating hormone levels in male veterans: A prospective pilot study.

Despite the common practice of intraarticular corticosteroid injections (ICSIs) for peripheral joint disease, little is known about their systemic effects on the hypothalamic-pituitary-gonadal axis. To assess the short-term effects of ICSIs on serum testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels together with changes in Shoulder Pain and Disability Index (SPADI) scores in a veteran population. Prospective pilot study. Outpatient musculoskeletal clinic. Thirty male veterans, median age 50 (range 30-69) years. Ultrasound-guided glenohumeral joint injection using 3 mL of 1% lidocaine HCl and 1 mL of 40 mg triamcinolone acetonide (Kenalog). Serum T, FSH, and LH levels, Quantitative Androgen Deficiency in the Aging Male (qADAM), and SPADI questionnaires at baseline, 1, and 4 week(s) post procedure. At 1 week post injection, serum T levels decreased by 56.8 ng/dL (95% confidence interval (CI): 91.8, 21.7, p = .002) compared with baseline. Between 1 and 4 weeks post injection, serum T levels increased by 63.9 ng/dL (95% CI: 26.5, 101.2, p = .001), recovering to near baseline levels. SPADI scores were reduced at 1 week (-18.3, 95% CI: -24.4, -12.1, p < .001) and 4 weeks (-14.5, 95% CI -21.1, -7.9, p < .001). A single ICSI can temporarily suppress the male gonadal axis. Future studies are needed to evaluate for long-term effects of multiple injections at a single setting and/or higher corticosteroid doses on male reproductive axis function.

Dual-contrast photon-counting micro-CT using iodine and a novel bismuth-based contrast agent

Objectives. To characterize for the first time in vivo a novel bismuth-based nanoparticular contrast agent developed for preclinical applications. Then, to design and test in vivo a multi-contrast protocol for functional cardiac imaging using the new bismuth nanoparticles and a well-established iodine-based contrast agent. Approach. A micro-computed tomography scanner was assembled and equipped with a photon-counting detector. Five mice were administered with the bismuth-based contrast agent and systematically scanned over 5 h to quantify the contrast enhancement in relevant organs of interest. Subsequently, the multi-contrast agent protocol was tested on three mice. Material decomposition was performed on the acquired spectral data to quantify the concentration of bismuth and iodine in multiple structures, e.g. the myocardium and vasculature. Main results. In the vasculature, the bismuth agent provides a peak enhancement of 1100 HU and a half-life of about 260 min. After the injection, it accumulates in the liver, spleen and intestinal wall reaching a CT value of 440 HU about 5 h post injection. Phantom measurements showed that the bismuth provides more contrast enhancement than iodine for a variety of tube voltages. The multi-contrast protocol for cardiac imaging successfully allowed the simultaneous decomposition of the vasculature, the brown adipose tissue and the myocardium. Significance. The new bismuth-based contrast agent was proven to have a long circulation time suitable for preclinical applications and to provide more contrast than iodine agents. The proposed multi-contrast protocol resulted in a new tool for cardiac functional imaging. Furthermore, thanks to the contrast enhancement provided in the intestinal wall, the novel contrast agent may be used to develop further multi contrast agent protocols for abdominal and oncological imaging.

Physiologic Effects of Microneedle-Mediated Intracochlear Dexamethasone Injection in the Guinea Pig.

Oral or intratympanic corticosteroids are commonly used to treat sudden sensorineural hearing loss (SSHL), tinnitus, and Meniere disease. Direct intracochlear delivery has been proposed to overcome the variability in bioavailability and efficacy of systemic or middle ear delivery. In this study, we aim to characterize the physiologic consequences of microneedle-mediated direct intracochlear injection of dexamethasone through the round window membrane (RWM). In Hartley guinea pigs (n = 5), a post-auricular incision followed by bullostomy was made to access the round window membrane. Using 100 μm diameter hollow microneedles, 1.0 μl of 10 mg/ml dexamethasone was injected through the RWM over 1 min. Compound action potential (CAP) and distortion product otoacoustic action emissions (DPOAE) were measured before perforation, at 1 h, and at 5 h following injection. CAP hearing thresholds were measured from 0.5 to 40 kHz, and DPOAE f2 frequencies ranged from 1.0 and 32 kHz. Repeated measures ANOVA followed by pairwise t-tests were used for statistical analysis. ANOVA identified significant CAP threshold shifts at four frequencies (4, 16, 36, and 40 kHz) and differences in DPOAE at 1 frequency (6 kHz). Paired t-tests revealed differences between the pre-perforation and 1 h time point. By 5 h post injection, both CAP hearing thresholds and DPOAE recover and are not significantly different from baseline thresholds. Direct intracochlear delivery of dexamethasone via microneedles results in temporary shifts in hearing thresholds that resolve by 5 hours, thus supporting microneedle technology for the treatment of inner ear disorders. NA Laryngoscope, 134:388-392, 2024.

Xenograft of human pluripotent stem cell-derived cardiac lineage cells on zebrafish embryo heart

Cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) are a promising cell source for regenerative medicine and drug discovery. However, the use of animal models for studying human cardiomyocytes derived from hiPSCs in vivo is limited and challenging. Given the shared properties between humans and zebrafish, their ethical advantages over mammalian models, and their immature immune system that is rejection-free against xenografted human cells, zebrafish provide a suitable alternative model for xenograft studies. We microinjected fluorescence-labeled cardiac lineage cells derived from hiPSCs, specifically mesoderm or cardiac mesoderm cells, into the yolk and the area proximal to the outflow tract of the linear heart at 24 hours post-fertilization (hpf). The cells injected into the yolk survived and did not migrate to other tissues. In contrast, the cells injected contiguous with the outflow tract of the linear heart migrated into the pericardial cavity and heart. After 1 day post injection (1 dpi, 22–24 hpi), the injected cells migrated into the pericardial cavity and heart. Importantly, we observed heartbeat-like movements of some injected cells in the zebrafish heart after 1 dpi. These results suggested successful xenografting of hiPSC-derived cardiac lineage cells into the zebrafish embryo heart. Thus, we developed a valuable tool using zebrafish embryos as a model organism for investigating the molecular and cellular mechanisms involved in the grafting process. This is essential in developing cell transplantation-based cardiac therapeutics as well as for drug testing, notably contributing to advancements in the field of cardio-medicine.

Peripheral and Central Impact of Methionine Source and Level on Growth Performance, Circulating Methionine Levels and Metabolism in Broiler Chickens.

The present study was designed to evaluate the effects of DL-methionine (DL-Met) 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), or S-(5'-Adenosyl)-L-methionine chloride (SAM), using feeding trial and central administration, on live performance, plasma metabolites, and the expression of feeding-related hypothalamic neuropeptides in broilers raised to a market age (35 d). Final average body weight (BW) and feed conversion ratio (FCR) from the feeding trial exceeded the performance measurements published by the primary breeder. At d35, the MTBHa group had better BW and lower feed intake, which resulted in a better FCR than the DL-Met group at 87 TSAA to lysine. At the molecular levels, the expression of hypothalamic neuropeptide (NPY) and monocarboxylate transporter (MCT) 2 did not differ between all treated groups; however, the mRNA abundances of hypothalamic MCT1 and orexin (ORX) were significantly upregulated in DL-Met- treated groups compared to the control. The ICV administration of SAM significantly reduced feed intake at all tested periods (from 30 to 180 min post injection) compared to the aCSF-treated group (control). The central administration of HMTBa increased feed intake, which reached a significant level only 60 min post administration, compared to the control group. ICV administration of DL-Met slightly increased feed intake compared to the control group, but the difference was not statistically discernable. Quantitative real-time PCR analysis showed that the hypothalamic expression of NPY, cocaine- and amphetamine-regulated transcript, MCT1, and MCT2 was significantly upregulated in the ICV-HMTBa group compared to the aCSF birds. The hypothalamic expression of the mechanistic target of rapamycin (mTOR), AMP-activated protein kinase (AMPKα1), D-amino acid oxidase, and hydroxyacid oxidase was significantly upregulated in DL-Met compared to the control group. The mRNA abundances of ORX were significantly increased in the hypothalamus of both DL-Met and HMTBa groups compared to the aCSF birds; however, mTOR gene expression was significantly downregulated in the SAM compared to the control group. Taken together, these data show, for the first time, that DL-Met and HMTBa have a common downstream (ORX) pathway, but also a differential central pathway, typically NPY-MCT for HMTBa and mTOR-AMPK for methionine.