Rapid, efficient, and economical synthesis of PET tracers in a droplet microreactor: application to O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET).

BackgroundConventional scale production of small batches of PET tracers (e.g. for preclinical imaging) is an inefficient use of resources. Using O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET), we demonstrate that simple microvolume radiosynthesis techniques can improve the efficiency of production by consuming tiny amounts of precursor, and maintaining high molar activity of the tracers even with low starting activity.ProceduresThe synthesis was carried out in microvolume droplets manipulated on a disposable patterned silicon "chip" affixed to a heater. A droplet of [18F]fluoride containing TBAHCO3 was first deposited onto a chip and dried at 100 °C. Subsequently, a droplet containing 60 nmol of precursor was added to the chip and the fluorination reaction was performed at 90 °C for 5 min. Removal of protecting groups was accomplished with a droplet of HCl heated at 90 °C for 3 min. Finally, the crude product was collected in a methanol-water mixture, purified via analytical-scale radio-HPLC and formulated in saline. As a demonstration, using [18F]FET produced on the chip, we prepared aliquots with different molar activities to explore the impact on preclinical PET imaging of tumor-bearing mice.ResultsThe microdroplet synthesis exhibited an overall decay-corrected radiochemical yield of 55 ± 7% (n = 4) after purification and formulation. When automated, the synthesis could be completed in 35 min. Starting with < 370 MBq of activity, ~ 150 MBq of [18F]FET could be produced, sufficient for multiple in vivo experiments, with high molar activities (48-119 GBq/μmol). The demonstration imaging study revealed the uptake of [18F]FET in subcutaneous tumors, but no significant differences in tumor uptake as a result of molar activity differences (ranging 0.37-48 GBq/μmol) were observed.ConclusionsA microdroplet synthesis of [18F]FET was developed demonstrating low reagent consumption, high yield, and high molar activity. The approach can be expanded to tracers other than [18F]FET, and adapted to produce higher quantities of the tracer sufficient for clinical PET imaging

Minimally invasive strategy for gynecologic cancer with solitary periacetabular metastasis

SummaryTumor with bone metastases to the periacetabulum is rare, and its surgical management is challenging. Instead of wide excision with reconstruction of the hip joint, we used a relatively noninvasive method to manage periacetabular metastasis. Such a procedure for this condition has the benefits of short surgical time, less bleeding, and fewer complications during surgery. Our surgical management of the case reported here included curettage, phenol cauterization and filling of cisplatin-loaded cement in order to reduce local recurrence. After following-up for 2 years, there was no local recurrence and disease progression

Acute Viral Hepatitis C-Induced Jaundice in Pregnancy

SummaryObjectiveAcute viral hepatitis C-induced jaundice in pregnancy is very rare and may be fatal. Here, we report a complicated case with acute hepatitis C-induced jaundice in pregnancy with successful managementCase ReportA 27-year-old pregnant woman, gravida 2, para 1, with gestational age of 36 weeks and 5 days, was referred to our hospital due to jaundice and elevated liver enzymes of undetermined cause. She had been suffering from general weakness, diarrhea and vomiting for 1 week, and jaundice with tea-colored urine for 3 days. At our medical center, acute viral hepatitis C-induced jaundice was suspected. Since her general condition deteriorated at 36 weeks and 6 days of gestation, we decided to induce labor. A male baby was born smoothly via the vaginal route, with birth weight 2,857 g, birth length 48.6 cm, and 1- and 5-minute Apgar scores of 7 and 9, respectively. Maternal condition improved dramatically after delivery and her serum liver enzymes and bilirubin levels gradually approached normal ranges.ConclusionMothers and fetuses with acute viral hepatitis C-induced jaundice during pregnancy are at great risk of mortality and morbidity. Timely termination may be one of the choices of treatment when fetal maturity has been reached and the maternal condition has deteriorated

Lipid-related residual risk and renal function for occurrence and prognosis among patients with first-event acute coronary syndrome and normal LDL cholesterol

<p>Abstract</p> <p>Background</p> <p>We investigated relationship of low levels of high density lipoprotein cholesterol (HDL-C), high levels of triglycerides, and renal function for the odds, prognosis and survival following acute coronary events among patients with a first event and normal low density lipoprotein cholesterol levels.</p> <p>Results</p> <p>A case-control study based on 557 patients and 1086 matched control subjects was conducted. Case patients were followed up for survival with a median of 1.9 years. Participants in the higher quintiles of HDL-C had lower odds to develop acute coronary events (the adjusted odds ratios were 0.24 for the second, 0.24 for the third, 0.10 for the fourth and 0.05 for the fifth quintile). Patients with normal glomerular filtration rate were at a lower risk for all-cause death. However, a reverse association between triglycerides and death risk was found: patients with higher triglycerides were at a lower risk for all-cause death (adjusted relative risk, 0.38 for triglycerides ranging from 82 to 132.9 mg/dL, and 0.14 for triglycerides > = 133 mg/dL).</p> <p>Conclusions</p> <p>Low HDL-C was significantly associated with acute coronary events, and triglyceride levels as well as renal function were inversely related to all-cause deaths after the coronary event.</p

A COMPUTATIONAL BIOMECHANICS STUDY TO INVESTIGATE THE EFFECT OF MYOELECTRIC STIMULATION ON PERONEAL MUSCLES IN PREVENTING INVERSION-TYPE ANKLE LIGAMENTOUS SPRAIN INJURY

A three-dimensional multi-body lower limb model with 16 bones and 22 ligaments was developed to study ankle ligamentous inversion sprain. A male athlete who was diagnosed with a grade I anterior talofibular ligament (ATaFL) sprain during an accidental injury in laboratory in a published report. His ankle kinematics injury data profile was computed. The effect of delivering myoelectric stimulation on peroneal muscles was simulated as torques during ankle inversion. Largest strain in the ATaFL was 8.3%, 9.0% and 11.4%, respectively, at different inversion velocity thresholds of 300 deg/s, 400 deg/s and 500 deg/s. A ligament strain/sprain more than 10-15% would lead to a ligament tear suggesting that applied muscle moments could successfully prevent ankle inversion sprain when an injury identification threshold does not reach 400 deg/s

A COMPUTATIONAL BIOMECHANICS STUDY TO INVESTIGATE THE EFFECT OF MYOELECTRIC STIMULATION ON PERONEAL MUSCLES IN PREVENTING INVERSION-TYPE ANKLE LIGAMENTOUS SPRAIN INJURY

A three-dimensional multi-body lower limb model with 16 bones and 22 ligaments was developed to study ankle ligamentous inversion sprain. A male athlete who was diagnosed with a grade I anterior talofibular ligament (ATaFL) sprain during an accidental injury in laboratory in a published report. His ankle kinematics injury data profile was computed. The effect of delivering myoelectric stimulation on peroneal muscles was simulated as torques during ankle inversion. Largest strain in the ATaFL was 8.3%, 9.0% and 11.4%, respectively, at different inversion velocity thresholds of 300 deg/s, 400 deg/s and 500 deg/s. A ligament strain/sprain more than 10-15% would lead to a ligament tear suggesting that applied muscle moments could successfully prevent ankle inversion sprain when an injury identification threshold does not reach 400 deg/s

Segregation analysis of apolipoprotein A1 levels in families of adolescents: A community-based study in Taiwan

BACKGROUND: Apolipoprotein (Apo) A1 is a protective factor for cardiovascular events. This study aimed to perform complex segregation analyses of Apo A1 levels in families of adolescents systematically ascertained from the junior high school students in a rural community. Both siblings and parents of the adolescent probands were recruited for the study. Apo A1 concentrations were measured by turbidimetric immunoassay methods. After adjustment for gender, age, body mass index, smoking and drinking status, residual values of Apo A1 were subjected to subsequent analyses. RESULTS: Significant mother-father and parent-offspring correlations were found. Commingling analyses indicated that a four-component distribution model was needed to account for the Apo A1 variation. Segregation analysis using regressive models revealed that the best-fit model of Apo A1 was a model of environmental effect plus familial correlation (heritability = 23.9%), in which a significant mother-father correlation existed. Models containing major gene effect could be rejected. CONCLUSION: These results suggest that variations of Apo A1 levels in the normal range, especially during adolescence, are likely to be influenced by multiple factors without significant contribution from major genes