The ultra high sensitivity blood counter: a compact, MRI-compatible, radioactivity counter for pharmacokinetic studies in µL volumes

Quantification of physiological parameters in preclinical pharmacokinetic studies based on nuclear imaging requires the monitoring of arterial radioactivity over time, known as the arterial input function (AIF). Continuous derivation of the AIF in rodent models is very challenging because of the limited blood volume available for sampling. To address this challenge, an Ultra High Sensitivity Blood Counter (UHS-BC) was developed. The device detects beta particles in real-time using silicon photodiodes, custom low-noise electronics, and 3D-printed plastic cartridges to hold standard catheters. Two prototypes were built and characterized in two facilities. Sensitivities up to 39% for¹⁸F and 58% for¹¹C-based positron emission tomography (PET) tracers were demonstrated.^99mTc and¹²⁵I based Single Photon Emission Computed Tomography (SPECT) tracers were detected with greater than 3% and 10% sensitivity, respectively, opening new applications in nuclear imaging and fundamental biology research. Measured energy spectra show all relevant peaks down to a minimum detectable energy of 20 keV. The UHS-BC was shown to be highly reliable, robust towards parasitic background radiation and electromagnetic interference in the PET or MRI environment. The UHS-BC provides reproducible results under various experimental conditions and was demonstrated to be stable over days of continuous operation. Animal experiments showed that the UHS-BC performs accurate AIF measurements using low detection volumes suitable for small animal models in PET, SPECT and PET/MRI investigations. This tool will help to reduce the time and number of animals required for pharmacokinetic studies, thus increasing the throughput of new drug development.

Identification of a novel nonsense variant in FYCO1 gene associated with infantile cataract and cortical atrophy

INTRODUCTION

Cataract is a major condition characterized by ocular lens opacification, resulting from alteration in the lens architecture, lens proteins or both. It is responsible for about one-third of infants' blindness worldwide. Variants in the FYCO1 gene have been associated with autosomal recessive infantile cataract.

MATERIAL AND METHODS

We conducted whole exome sequencing (WES) in a nine months old male patient who was referred for genetic investigation because of infantile cataract. WES analysis revealed the presence of a homozygous pathogenic variant (c.2365C>T) in exon 8 of the FYCO1 gene.

RESULTS AND DISCUSSION

This is the first report on a Lebanese infant with infantile cataract and cortical atrophy which was not previously reported, resulting from a novel homozygous FYCO1 variant; thus expanding the clinical phenotypic spectrum of FYCO1 involvement.

The impact of protocol-based high-intensity pharmacological thromboprophylaxis on thrombotic events in critically ill COVID-19 patients

The reported incidence rate of venous and arterial thrombotic events in critically ill patients with COVID‐19 infections is high, ranging from 20% to 60%. We adopted a patient‐tailored thromboprophylaxis protocol based on clinical and laboratory presentations for these patients in our institution. We hypothesised that patients who received high‐intensity thromboprophylaxis treatment would experience fewer thrombotic events. The aims of our study were to explore the incidence of thrombotic events in this population; to assess independent factors associated with thrombotic events and to evaluate the incidence of haemorrhagic events. A retrospective review of all adult patients with confirmed SARS‐CoV‐2 infection admitted to the intensive care unit (ICU) between 1 March and 29 May 2020 was performed. The primary outcome was a composite of venous and arterial thrombotic events diagnosed during the ICU stay. Multivariable logistic regression was used to identify the independent factors associated with thrombotic events. A total of 188 patients met the inclusion criteria. All received some type of thromboprophylaxis treatment except for six patients who did not receive any prophylaxis. Of the 182 patients who received thromboprophylaxis, 75 (40%) received high‐intensity thromboprophylaxis and 24 (12.8%) were treated with therapeutic anticoagulation. Twenty‐one patients (11.2%) experienced 23 thrombotic events (incidence rate of 12.2% (95%CI 7.9–17.8)), including 12 deep venous thromboses, 9 pulmonary emboli and 2 peripheral arterial thromboses. The multivariable logistic regression analysis showed that only D‐dimer (OR 2.80, p = 0.002) and high‐intensity thromboprophylaxis regimen (OR 0.20, p = 0.01) were independently associated with thrombotic events. Thirty‐one patients (16.5%) experienced haemorrhagic events; among them, 13 were classified as major bleeding according to the International Society on Thrombosis and Haemostasis criteria. Therapeutic anticoagulation, but not the high‐intensity thromboprophylaxis regimen, was associated with major bleeding. A proactive approach to the management of thromboembolism in critically ill COVID‐19 patients utilising a high‐intensity thromboprophylaxis regimen in appropriately selected patients may result in lower thrombotic events without increasing the risk of bleeding.

Structural Basis for Achieving GSK-3β Inhibition with High Potency, Selectivity, and Brain Exposure for Positron Emission Tomography Imaging and Drug Discovery

Using structure-guided design, several cell based assays, and microdosed positron emission tomography (PET) imaging, we identified a series of highly potent, selective, and brain-penetrant oxazole-4-carboxamide-based inhibitors of glycogen synthase kinase-3 (GSK-3). An isotopologue of our first-generation lead, [3H]PF-367, demonstrates selective and specific target engagement in vitro, irrespective of the activation state. We discovered substantial ubiquitous GSK-3-specific radioligand binding in Tg2576 Alzheimer's disease (AD), suggesting application for these compounds in AD diagnosis and identified [11C]OCM-44 as our lead GSK-3 radiotracer, with optimized brain uptake by PET imaging in nonhuman primates. GSK-3β-isozyme selectivity was assessed to reveal OCM-51, the most potent (IC50 = 0.030 nM) and selective (>10-fold GSK-3β/GSK-3α) GSK-3β inhibitor known to date. Inhibition of CRMP2T514 and tau phosphorylation, as well as favorable therapeutic window against WNT/β-catenin signaling activation, was observed in cells.

Supplementing dams with both arachidonic and docosahexaenoic acid has beneficial effects on growth and immune development

Omega-3 long-chain polyunsaturated fatty acids (LCPUFAS) modulate immune cells in vitro and in vivo. This study investigated the effects of enriching the maternal diet with the n-6 and n-3 LCPUFAs, arachidonic (20:4n-6, 0.6%wt ARA) and docosahexaenoic acid (22:6n-3, 0.32%wt DHA), or 1:1 and 2:1 ratios (ARA: DHA) on total lipids in milk, total lipids, and immunophenotypes in plasma, lymph nodes, and spleen from isolated immune cells from 28d old pups. From day 15 of gestation to day 3 pp, Sprague-Dawley dams were fed a commercial chow. On day 3 pp litters were culled and pups (4 males and 2 females) randomly cross-fostered to dams who were randomized to one of the 5 experimental diets resulting in 20 male and 10 female pups/diet group. Dams fed ARA or ARA: DHA had 28-36% more 20:4n-6 in milk and feeding DHA or ARA: DHA doubled 22:6n-3 in milk lipids (P<0.05). Feeding 1:1 or 2:1 ARA: DHA resulted in greater pup weight at weaning (P<0.05). Compared to the control pups, ARA + DHA fed pups had a lower proportion of splenic CD45RA+ lymphocytes. In summary, postpartum supplementation with a combination of ARA + DHA, compared to ARA or DHA alone, resulted in a higher content of ARA and DHA in dam's milk and tissues and had positive effects on growth, accompanied by evidence of progression toward a mature immune phenotype, and suggests a need for ARA when DHA is supplemented in the early diet. Additional investigations are needed of ARA immunomodulation to better understand and estimate nutritional requirements for LCPUFAs during early development.

A new tobamovirus infecting tomato crops in Jordan

In this study, we completed the whole genome sequence of a new tobamovirus isolated from tomato plants grown in greenhouses in Jordan during the spring of 2015. The 6393-nt single-stranded RNA (ssRNA) genome encodes four proteins, as do other tobamoviruses: two replication-related proteins of 126 kDa and 183 kDa, a 30-kDa movement protein (MP) and a 17.5-kDa coat protein (CP). Phylogenetic analysis showed that this virus does not group with either the tomato mosaic virus (ToMV) or the tobacco mosaic virus (TMV) clades. Instead, it stems from a branch leading to the TMV clade. Analysis of possible recombination events between this virus and representative isolates of closely related tomato-infecting tobamoviruses showed that at least one region originated by recombination. We provide evidence that we have identified a new tobamovirus, for which we propose the name "tomato brown rugose fruit virus".

Distribution of omega-6 and omega-3 polyunsaturated fatty acids in the whole rat body and 25 compartments

The steady state compositions of omega-6 and omega-3 polyunsaturated fatty acids (PUFA) throughout the various viscera and tissues within the whole body of rats have not previously been described in a comprehensive manner. Dams consumed diets containing 10wt% fat (15% linoleate and 3% α-linolenate). Male offspring (n=9) at 7-week of age were euthanized and dissected into 25 compartments. Total lipid fatty acids for each compartment were quantified by GC/FID and summed for the rat whole body; total n-6 PUFA was 12wt% and total n-3 PUFA was 2.1% of total fatty acids. 18:2n-6 accounted for 84% of the total n-6 PUFA, 20:4n-6 was 12%, 18:3n-3 was 59% of the total n-3 PUFA, 20:5n-3 was 2.1%, and 22:6n-3 was 32%. The white adipose tissue contained the greatest amounts of 18:2n-6 (1.5g) and 18:3n-3 (0.2g). 20:4n-6 was highest in muscle (60mg) and liver (57mg), while 22:6n-3 was greatest in muscle (46mg), followed by liver (27mg) and carcass (20mg). In terms of fatty acid composition expressed as a percentage, 18:2n-6 was the highest in the heart (13wt%), while 18:3n-3 was about 1.3wt% for skin, white adipose tissue and fur. 20:4n-6 was highest (21-25wt%) in the circulation, kidney, and spleen, while 22:6n-3 was highest in the brain (12wt%), followed by the heart (7.9wt%), liver (5.9wt%), and spinal cord (5.1wt%). Selectivity was greatest when comparing 22:6n-3 in brain (12%) to white adipose (0.08%) (68-fold) and 22:5n-6 in testes (15.6%) compared to white adipose (0.02%), 780-fold.

Abstract 4949: In vitro and in vivo investigation of the novel, first-in-class, Guanylyl Cyclase C (GCC) targeted 68Ga labeled heat stable peptide MLN6907 ([68Ga]MLN6907) for tumor imaging

A novel, first-in-class, 68Ga labeled DOTA-para-bn-SCN-Ahx-STp(5-18) 2.2kDa peptide [MLN6907] ([68Ga]MLN6907) with high affinity to the guanalyl cyclase C (GCC) receptor has been developed to select cancer patients for treatment with GCC targeted therapies using PET/CT. GCC is sequestered exclusively in the gastrointestinal luminal compartment except under malignant transformation where it is then made accessible to intravenous agents.

Conventional patient selection strategies often rely on an analytical IHC or total protein based assessment of a tumor biopsy which can be limited to an archival tissue sample from a single region of a single lesion. Imaging may offer whole body, real time, multi-region and multi lesion assessment of target levels. In addition, functional parameters associated with receptor kinetics may also be explored in vivo.

68Ga has a high avidity for the common chelating moiety DOTA. Furthermore, its short radioactive half life (half-life, 68.3 minutes) matches well to a biological targeting moiety like a peptide with its rapid biological clearance and fast diffusion to target thus providing optimal tumour-to-normal tissue contrast.

In vitro: Cellular competitive binding studies confirmed high affinity of non-radiolabeled MLN6907 for its cognate receptor, GCC, with a KD of 3.2 nM. Upon ligand-recpetor binding, MLN6907 is internalized rapidly with a half-life of 56 min.

In vivo: Similar to other radiolabeled peptides, [68Ga]MLN6907 clears rapidly from blood (t1/2 = 26 min) through renal excretion as investigated in Long Evans rats and non-human primate studies. The radiation exposure from [68Ga]MLN6907 was highest in the kidney and bladder indicating that renal excretion was a primary route of elimination. Using OLINDA/EXM software, the effective dose was estimated to be 0.013 mSv/MBq in man. In tumor bearing C.B-17 SCID mice, both ex vivo and in vivo signal was measured in both human tumor cell lines and primary human tumor xenografts with varied GCC levels and compared to non tumor bearing tissues. [68Ga]MLN6907 total uptake (%I.D./g) varied across the different tumors investigated. Using the unlabeled precursor, no toxicity was observed in repeat dose rat and monkey studies. Using the rat as the more conservative species for dose estimation, it was calculated that a human equivalent dose of 282 μg would be safe. However, using a saturable effect PK/PD compartment model for mice and humans, we estimated a single human dose of less than 100μg would provide resolution of tumors with different GCC levels.

Collectively, biological, pharmacokinetic and safety data obtained with [68Ga]MLN6907 are consistent with an effective GCC PET imaging agent.

[68Ga]MLN6907 is being developed clinically as a single, i.v., microdose GCC PET imaging agent in a Phase 1 investigation in patients with surgically resectable metastatic colorectal carcinoma

Citation Format: Donna Cvet, Robert Robertson, Melissa Saylor, Jennifer Terkelsen, Ozlem Yardibi, Maria Borland, Nicolas Salem, Petter Veiby, Todd Sells, Mary Carsillo, Johnny Yang, Shu-Wen Teng, John Hoppin, Kelly Orcutt, Jacob Hesterman, Jeffery Norenberg, Tamara Anderson, Mike Schulz, Mary Ruscowski, Marc Berridge, Steven Mather, Daniel P. Bradley. In vitro and in vivo investigation of the novel, first-in-class, Guanylyl Cyclase C (GCC) targeted 68Ga labeled heat stable peptide MLN6907 ([68Ga]MLN6907) for tumor imaging. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4949. doi:10.1158/1538-7445.AM2014-4949

First Report of Fusarium oxysporum f. sp. cubense Tropical Race 4 Associated with Panama Disease of Banana outside Southeast Asia

Fusarium wilt or Panama disease of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is among the most destructive plant diseases (3). Race 1 ravaged 'Gros Michel'-based export trades until the cultivar was replaced by resistant Cavendish cultivars. However, a new variant of Foc, tropical race 4 (TR4), was identified in Southeast Asia in 1992 and has spread throughout the region (3). Cavendish clones, which are most important in subsistence and export production, are among the wide range of cultivars that are affected, and there is a huge concern that TR4 will further disseminate in Africa since its presence was announced in November 2013 and move into Latin America, thereby threatening other vital banana-growing regions. In Jordan, Cavendish bananas are produced on 1,000 to 1,500 ha in the Jordan Valley (32°N, 35.5°E). In 2006, symptoms of Fusarium wilt were observed and sampled for the isolation of Foc. On half-strength PDA amended with 100-ppm streptomycin sulfate, pale salmon-colored colonies with floccose mycelia developed consistently from surface-disinfested xylem. Single microconidia from these colonies were transferred to half-strength PDA, and conidia and mycelia from these monospore colonies were stored at -80°C in 15% glycerol. On banana leaf agar (Co₆₀-irradiated leaf tissue on water agar), isolates resembled F. oxysporum phenotypically by producing infrequent three- to five-celled macroconidia, copious, usually aseptate microconida on monophialides, and terminal and intercalary chlamydospores after 2 weeks (2). With nitrate-nonutilizing (nit) mutants and testers for different vegetative compatibility groups (VCGs), each of seven examined monospore isolates were placed in VCG 01213, which contains only strains of TR4 (3). Total DNA was extracted from six isolates and PCR analyses, which confirmed their identity as TR4 (1). Subsequently, one of the isolates (JV11) was analyzed for pathogenicity. Inoculum production and inoculation were according to (1) by dipping (30 min) root-wounded 10-week-old plants of the Cavendish cv. Grand Naine in 2 liters of spore suspension (1.0 × 10⁶ spores/ml). Inoculated plants were then placed in sand in 3-liter pots under 28°C, 70% relative humidity, and a 16/8-h light/darkness photoperiod. Sets of three plants were each treated with either JV11 or two TR4 controls (isolate II-5 and a strain isolated from an affected Cavendish plant in Mindanao, Philippines, both of which were diagnosed as TR4 by PCR and pathogenicity analyses). Control sets were either treated with race 1 originating from Cruz das Almas, Bahia, Brazil (1), or water. After 2 weeks, plants inoculated with JV11 and TR4 controls produced typical symptoms of Fusarium wilt. After 4 weeks, tissue was collected from all plants and plated on Komada's medium. TR4 was directly confirmed by PCR (1), either directly from symptomatic plants (JV11 and TR4 controls), or from isolates that were recovered from these plants. Nothing was re-isolated from race 1 inoculated plants and water controls, which remained asymptomatic. This is the first report of TR4 affecting Cavendish outside Southeast Asia, is its northernmost outbreak, and represents a dangerous expansion of this destructive race. Currently, 80% of the Jordan Valley production area is affected by Fusarium wilt, and 20 to 80% of the plants are affected in different farms. References: (1) M. A. Dita et al. Plant Pathol. 59:348, 2010. (2) J. F. Leslie and B. A. Summerell. The Fusarium Lab Manual. Blackwell, Ames, 2006. (3) R. C. Ploetz. Phytopathology 96:653, 2006.

Transfer of omega-3 fatty acids across the blood-brain barrier after dietary supplementation with a docosahexaenoic acid-rich omega-3 fatty acid preparation in patients with Alzheimer's disease: the OmegAD study

OBJECTIVE

Little is known about the transfer of essential fatty acids (FAs) across the human blood-brain barrier (BBB) in adulthood. In this study, we investigated whether oral supplementation with omega-3 (n-3) FAs would change the FA profile of the cerebrospinal fluid (CSF).

METHODS

A total of 33 patients (18 receiving the n-3 FA supplement and 15 receiving placebo) were included in the study. These patients were participants in the double-blind, placebo-controlled randomized OmegAD study in which 204 patients with mild Alzheimer's disease (AD) received 2.3 g n-3 FA [high in docosahexaenoic acid (DHA)] or placebo daily for 6 months. CSF FA levels were related to changes in plasma FA and to CSF biomarkers of AD and inflammation.

RESULTS

At 6 months, the n-3 FA supplement group displayed significant increases in CSF (and plasma) eicosapentaenoic acid (EPA), DHA and total n-3 FA levels (P < 0.01), whereas no changes were observed in the placebo group. Changes in CSF and plasma levels of EPA and n-3 docosapentaenoic acid were strongly correlated, in contrast to those of DHA. Changes in DHA levels in CSF were inversely correlated with CSF levels of total and phosphorylated tau, and directly correlated with soluble interleukin-1 receptor type II. Thus, the more DHA increased in CSF, the greater the change in CSF AD/inflammatory biomarkers.

CONCLUSIONS

Oral supplementation with n-3 FAs conferred changes in the n-3 FA profile in CSF, suggesting transfer of these FAs across the BBB in adults.

Buccodental side effects of sunitinib in patients with metastatic renal cell carcinoma

BACKGROUND

Sunitinib is a tyrosine kinase inhibitor approved for the treatment of renal cell carcinoma (RCC). Few data evaluated severe buccodental adverse events. The aim of this study was to evaluate sunitinib buccodental toxicity in patients with metastatic RCC and to compare it with that of standard chemotherapy in patients with other solid cancers.

METHODS

Patients with RCC treated with sunitinib and patients with other solid tumours treated with chemotherapy were followed for 3 months. Data on dental appliances, oral hygiene/care practices before and during treatment were collected.

RESULTS

A total of 116 patients were included (58 RCC treated by sunitinib: group S, and 58 treated by chemotherapy: group C). No differences in dental care habits were noted before treatment. In group S, patients reported significantly more frequent pain (P<0.01), teeth instability (P=0.01), gingival bleeding (P=0.01) and change in teeth colour (P=0.02). In all, 58% of patients in this group had to modify their diet (P<0.01). Frequency of dentist visits for teeth removal was increased (25% vs 8%, P=0.01).

CONCLUSION

Sunitinib seems to increase buccodental toxicity as compared with chemotherapy. This finding emphasises the need for optimal dental care and standardised dental follow-up in patients treated with sunitinib.

A novel deletion in ZBTB24 in a Lebanese family with immunodeficiency, centromeric instability, and facial anomalies syndrome type 2

The immunodeficiency, centromeric instability and facial anomalies (ICF) syndrome is a rare autosomal recessive disease characterized by targeted chromosome breakage, directly related to a genomic methylation defect. It manifests with phenotypic and clinical variability, with the most consistent features being developmental delay, facial anomalies, cytogenetic defects and immunodeficiency with a reduction in serum immunoglobulin levels. From the molecular point of view, ICF syndrome was always divided into ICF type I (ICF1) and ICF type 2 (ICF2). Mutations in DNMT3B gene are responsible for ICF1, while mutations in ZBTB24 have been reported to be responsible for ICF2. In this study, we describe a Lebanese family with three ICF2 affected brothers. Sanger sequencing of the coding sequence of ZBTB24 gene was conducted and revealed a novel deletion: c.396_397delTA (p.His132Glnfs*19), resulting in a loss-of-function of the corresponding protein. ZBTB24 belongs to a large family of transcriptional factors and may be involved in DNA methylation of juxtacentromeric DNA. Detailed molecular and functional studies of the ZBTB24 and DNMT3B genes are needed to understand the pathophysiology of ICF syndrome.

Could thyroid dysfunction influence outcome in sunitinib-treated metastatic renal cell carcinoma?

BACKGROUND

Sunitinib is a standard of care for metastatic renal cell carcinoma (mRCC). Hypothyroidism is frequently observed under sunitinib therapy. This study was conducted to prospectively determine the correlation between thyroid function and progression-free survival (PFS) in this population.

PATIENTS AND METHODS

One hundred and eleven mRCC patients treated with sunitinib were evaluated for serum thyroid-stimulating hormone (TSH) and T4 levels before treatment and every 6 weeks during treatment. Survival was analysed according to a landmark method with a cut-off of 6 months, excluding early progressive or early-censored patients.

RESULTS

Out of the 102 patients with normal baseline thyroid function, 53% developed thyroid dysfunction, including 95% hypothyroidisms out of which 90.9% received L-thyroxine replacement. Median time to TSH alteration was 5.4 months. Median PFS was 11.7 months for the entire population. Median PFS was not different between the groups with abnormal or normal thyroid function after 6 months of treatment (18.9 and 15.9 months, respectively, log-rank P = 0.94, hazard ratio = 1.02, 95% confidence interval = 0.54-1.93). There was no difference even after adjustment for Memorial Sloan-Kettering Cancer Centre classification and therapy line.

CONCLUSIONS

Abnormal thyroid function with hormonal substitution did not increase survival in our population, independent of initial prognosis and previous treatments. Larger comparative studies are deserved to validate these conclusions.

P3-12-05: Breast Cancer Recurrence: 2nd Conservative Treatment Versus Mastectomy

Objectives: Mastectomy (Mt) is considered standard treatment for isolated local recurrence (LR) of breast carcinoma. The aim of our study was to evaluate a second conservative treatment (defined as lumpectomy followed by interstitial brachytherapy (LpIB)) and to determine if it compares favorably with the current standard treatment. Materials and methods: Between January 1981 and December 2009, 348 patients were treated to the Paoli Calmettes Institute (IPC) for an isolated LR: 232 (66,7 %) underwent Mt, 62 (17,8 %) received a second radio-surgical conservative treatment (LpIB) and 54 (15,5 %) a 2nd single surgical treatment (Lp).

We classified each population according to the well known prognosis factors.

Then, populations Mt and LpIB were matched taking into account these criteria to compare the overall survival (OS), metastasis free survival (MFS) and 2nd local recurrence free survival according to the treatment delivered.

Results: On 348 reviewed patients, with a median follow-up of 73,3 months, 65 patients died (42/232 Mt, 8/62 TecCur, 15/54 Tec) and 100 presented metastasis (64/232 Mt, 15/62 TecCur, 21/54 Tec). There was no difference in MFS for the 2 groups, LpIB and Mt (80 % at 5 years) and the OS was non significantly better in the group LpIB compared to the group Mt (90 % and 82 % at 5 years respectively, p=0,28), whereas in the LpIB group 17% and 30% presented a relapse at 5 years and 10 years respectively.

They subsequently underwent a salvage mastectomy.

Worse results were obtained with lumpectomy alone (OS = 72 % and MFS = 68 % at 5 years) compared with 2 other option treatments.

Conclusion: A second conservative treatment for breast cancer recurrence, i.e. lumpectomy and interstitial brachytherapy, is possible for selected patients, without any negative impact on overall survival, nor metastasis free survival.

Keywords: Local recurrence, interstitial brachytherapy, lumpectomy, conservative treatment, mastectomy, overall survival, metastasis free survival, breast carcinoma.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-12-05.

[(Methyl)1-(11)c]-acetate metabolism in hepatocellular carcinoma

PURPOSE

Studies have established the value of [(methyl)1-(11)C]-acetate ([(11)C]Act) combined with 2-deoxy-2[(18)F]fluoro-D-glucose (FDG) for detecting hepatocellular carcinoma (HCC) using positron emission tomography (PET). In this study, the metabolic fate of [(11)C]Act in HCC was characterized.

METHODS

Experiments with acetic acid [1-(14)C] sodium salt ([(14)C]Act) were carried out on WCH-17 cells and freshly derived rat hepatocytes. PET scans with [(11)C]Act were also carried out on woodchucks with HCC before injection of [(14)C]Act. The radioactivity levels in different metabolites were quantified with thin-layer chromatography.

RESULTS

In WCH-17 cells, the predominant metabolite was phosphatidylcholine (PC). Regions of HCCs with the highest [(11)C]Act uptake had higher radioactivity accumulation in lipid-soluble compounds than surrounding hepatic tissues. In those regions, PC and triacylglycerol (TG) accumulated more radioactivity than in surrounding hepatic tissues.

CONCLUSIONS

High [(11)C]Act uptake in HCC is associated with increased de novo lipogenesis. PC and TG are the main metabolites into which the radioactive label from [(11)C]Act is incorporated in HCC.

Whole animal imaging

Translational research plays a vital role in understanding the underlying pathophysiology of human diseases, and hence development of new diagnostic and therapeutic options for their management. After creating an animal disease model, pathophysiologic changes and effects of a therapeutic intervention on them are often evaluated on the animals using immunohistologic or imaging techniques. In contrast to the immunohistologic techniques, the imaging techniques are noninvasive and hence can be used to investigate the whole animal, oftentimes in a single exam which provides opportunities to perform longitudinal studies and dynamic imaging of the same subject, and hence minimizes the experimental variability, requirement for the number of animals, and the time to perform a given experiment. Whole animal imaging can be performed by a number of techniques including x-ray computed tomography, magnetic resonance imaging, ultrasound imaging, positron emission tomography, single photon emission computed tomography, fluorescence imaging, and bioluminescence imaging, among others. Individual imaging techniques provide different kinds of information regarding the structure, metabolism, and physiology of the animal. Each technique has its own strengths and weaknesses, and none serves every purpose of image acquisition from all regions of an animal. In this review, a broad overview of basic principles, available contrast mechanisms, applications, challenges, and future prospects of many imaging techniques employed for whole animal imaging is provided. Our main goal is to briefly describe the current state of art to researchers and advanced students with a strong background in the field of animal research.

Abstract P6-03-03: Could We Reduce the Number of Exams in the Follow-Up of Breast Cancer Survivors?

Background. The aim of this retrospective study was to determine by which way was diagnosed any breast cancer recurrence after the end of the adjuvant treatment and to draw guidelines for exams for the follow-up. Materials and methods. Between January 1995 to December 2005, 5419 patients were treated for non metastatic breast cancer in our institute, out of which 662 experienced a relapse either local or metastatic. The charts of 608 of these patients were analysable, and retrospectively reviewed. For each case, we looked at the exams or clinical symptom which revealed the recurrence.

Results. Among the 608 patients who recurred, 173 patients (28%) experienced an isolated local relapse, while 12 experienced a contralateral breast cancer (2%), 423 experienced either a metastatic or metastatic plus local relapse (65% and 5%, respectively). Local relapses were detected in most of cases either clinically (42%) or on mammography and mammary ultrasound (US) (55%). An isolated increase of blood tumor marker (CA 15.3) revealed the relapse in 24% of cases (in 33% of cases for distant relapses and 3% for isolated local relapses). The remaining 67% of cases with metastases were diagnosed by clinical symptoms in 47% of cases, imaging in 22% of cases (bone scan in 6%, liver US 5%, mammography 1%, TDM 5%, chest X-ray 2%). In these cases of radiographically detected metastases clinical exam and/or tumor markers levels were abnormal in 42% of cases.

Conclusion. A follow-up with a systematically clinical exam, mammography and mammary US, and blood tumor markers assessment permits the diagnosis of 100 percent of local relapse, 100% of contralateral breast cancer, and 89% of metastatic disease. Thus imaging exams could be avoided routinely, with less stress for the patient and improvement of the health cost.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-03-03.