Comparison of18F-fluoromethylcholine and 2-deoxy-D-glucose in the distribution of tumor and inflammation

PURPOSE: The distribution characteristics of 18F-fluoromethylcholine (18F-choline) in tumor and inflammatory tissue were compared with those of 14C or 3H-2-deoxyglucose (2DG) as a substitute for fluorodeoxyglucose (FDG). METHODS: A solid tumor model of AH 109A in the back of Donryu rats and an aseptic inflammation model of turpentine oil injection subcutaneously in rats were used for experiments. Tissue distribution was examined at 5, 30 and 60 min after injection of a mixture of 18F-choline and 3H-2DG. Double-tracer high-resolution autoradiographs (ARGs) of tumor and inflammation were obtained using 18F-choline and 14C-2DG. Whole body (WB) ARG was performed with 18F-choline. RESULTS: Tumor uptake of 18F-choline reached a peak at 30 min, when the tumor to blood ratio was 5.1. Both tumor and inflammation uptake of 2DG were higher than those of 18F-choline. 18F-choline uptake by inflammation was lower than that by tumor. The tumor to brain uptake ratio was 5.7 with 18F-choline and 1.2 with 2DG. In the ARG of inflammation, linear or ring-like structures of 2DG uptake were observed in the wall of the abscess, but were not identified with 18F-choline. Photomicrography showed that the uptake was limited to granulocytes, macrophages and fibroblasts, consistent with sub-acute or chronic inflammation. CONCLUSION: 18F-choline uptake by inflammation was lower than that of 2DG in the tissue distribution study, and 18F-choline uptake by abscess wall was significantly lower than that of 2DG in the autoradiography study. Our results may suggest the feasibility of 18F-choline-PET imaging for the differential diagnosis of cancer and chronic inflammation in lung and brain.     

Acute and late genitourinary toxicity of conformal radiotherapy for prostate cancer

Purpose The aim of this study was to identify predictive factors for genitourinary (GU) toxicity in prostate cancer patients who underwent conformal radiotherapy (CRT). Materials and methods In this study we analyzed 154 cases of T1-3N0M0 prostate adenocarcinoma and evaluated the occurrence rate of acute and late GU toxicity and the duration of acute toxicity according to clinical parameters: age, transurethral resection of the prostate prior to CRT, hormone therapy, CRT dose, length of planning target volume (PTV). Results Altogether, 41% of the patients developed grade 2 or higher acute GU toxicity. Longer PTV was significantly associated with a higher incidence of acute GU toxicity (>7 cm, 53%; ≤7 cm, 31%; P = 0.003), and hormone therapy prolonged the duration of the toxicity (P = 0.007). Grade 1 or higher late GU toxicity developed in 23% of the patients, and the 2-year late GU toxicity-free survival rate was 79%. Acute GU toxicity was significantly associated with the late GU toxicity-free survival rate (grade 0–1, 88.7%; grade 2–4, 73.2%; P = 0.0007). Conclusion The length of PTV and hormone therapy were predictive factors for acute GU toxicity. Furthermore, acute GU toxicity was the most important predictive factor for late GU toxicity.     

New modalities and aspects of antiplatelet therapy for stroke prevention

Antiplatelet therapy is indicated for secondary prevention of ischaemic stroke. The first-line antiplatelet agent is aspirin. The effect of aspirin is, however, very limited, and this limited effect of aspirin is argued with termed 'aspirin resistance'. Strategies against aspirin resistance may include alternative use of other antiplatelet agents, combination of aspirin with other antiplatelet agents and investigation into molecular targets to develop novel antiplatelet agents. Progress in antiplatelet therapy should be directed at further reducing the risk of ischaemic events including ischaemic stroke without increasing the risk of haemorrhagic events including haemorrhagic stroke.     

The effects of external cues on ankle control during gait initiation in Parkinson's disease

The present study investigated the effects of external cues on motor control of the ankle joint during gait initiation in patients with Parkinson's disease (PD) and in age-matched healthy subjects. The soleus H-reflexes were recorded during self-generated and cue-triggered gait initiation. The tibialis anterior muscle burst during cue-triggered gait initiation was found to be significantly larger than that during self-generated gait initiation in both groups. External cues significantly increased soleus H-reflex depression during gait initiation in PD patients, although this significant increase was not present in healthy subjects. These findings indicate that external cues affect motor control of the extensor muscle of the ankle joint during gait initiation in PD patients.     

Demonstration of type II latency in T lymphocytes of Epstein–Barr Virus‐associated hemophagocytic lymphohistiocytosis

Epstein–Barr virus (EBV) is the most common infectious cause of non‐genetic hemophagocytic lymphohistiocytosis (HLH). To investigate EBV‐infected lymphocytes and immune dysfunction in EBV‐associated HLH, blood samples from a 6‐year‐old boy were longitudinally analyzed using molecular techniques. EBV‐positive lymphocytes were detected as CD5⁺, CD8⁺, and/or HLA DR⁺ lymphocytes on Day 25 of the disease, mostly disappearing thereafter. CD8⁺ cells specific for lytic antigen BRLF1 were detected, but cells specific for latent antigens EBNA3 and LMP2 were not. EBV genes EBNA1, LMP1, LMP2, EBER1, BARTs were detected, suggesting a latency type II gene expression pattern in this case. Pediatr Blood Cancer 2013;60:326–328. © 2012 Wiley Periodicals, Inc.     

Comparison of the binding characteristics of [18F]THK-523 and other amyloid imaging tracers to Alzheimer��s disease pathology

Purpose

Extensive deposition of senile plaques and neurofibrillary tangles in the brain is a pathological hallmark of Alzheimer??s disease (AD). Although several PET imaging agents have been developed for in vivo detection of senile plaques, no PET probe is currently available for selective detection of neurofibrillary tangles in the living human brain. Recently, [¹⁸F]THK-523 was developed as a potential in vivo imaging probe for tau pathology. The purpose of this study was to compare the binding properties of [¹⁸F]THK-523 and other amyloid imaging agents, including PiB, BF-227 and FDDNP, to synthetic protein fibrils and human brain tissue.

Methods

In vitro radioligand binding assays were conducted using synthetic amyloid ??₄₂ and K18??K280-tau fibrils. Nonspecific binding was determined by the addition of unlabelled compounds at a concentration of 2???M. To examine radioligand binding to neuropathological lesions, in vitro autoradiography was conducted using sections of AD brain.

Results

[¹⁸F]THK-523 showed higher affinity for tau fibrils than for A?? fibrils, whereas the other probes showed a higher affinity for A?? fibrils. The autoradiographic analysis indicated that [¹⁸F]THK-523 accumulated in the regions containing a high density of tau protein deposits. Conversely, PiB and BF-227 accumulated in the regions containing a high density of A?? plaques.

Conclusion

These findings suggest that the unique binding profile of [¹⁸F]THK-523 can be used to identify tau deposits in AD brain.     

Differentiation of regioisomeric fluoroamphetamine analogs by gas chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry

In recent years, a large number of clandestinely produced controlled-substance analogs (designer drugs) of amphetamine with high structural variety have been detected in forensic samples. Analytical differentiation of regioisomers is a significant issue in forensic drug analysis because, in most cases, legal controls are placed only on one or two of the three isomers. In this study, we used gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for the differentiation of regioisomers of fluoroamphetamine analogs (fluoroamphetamines and fluoromethamphetamines), which were synthesized in our laboratories. Free bases and their acylated and silylated derivatives were subjected to GC–MS analysis using DB-1ms, DB-5ms, and DB-17ms capillary columns. The separation of free bases was incomplete on all columns. Trifluoroacetyl derivatives of 3- and 4-positional isomers showed slight separation on DB-1ms and DB-5ms. On the other hand, trimethylsilyl derivatization enabled baseline separation of six fluoroamphetamine analogs on DB-1ms and DB-5ms columns, which was sufficient for unequivocal identification. For LC–MS/MS, a pentafluorophenyl column was able to separate six regioisomeric fluoroamphetamine analogs but a conventional C18 column could not achieve separation between 3- and 4-positional isomers. These results show that a suitable choice of derivatization and analytical columns allows the differentiation of regioisomeric fluoroamphetamine analogs.     

Combined free autologous auricular cartilage and fascia lata graft repair for a recurrent tracheoesophageal fistula

Pediatric Surgery International - Repair of recurrent tracheoesophageal fistula (TEF) after repair of congenital esophageal atresia continues to be a difficult problem. The most common re-operation...     

The current status of an FDG-PET cancer screening program in Japan, based on a 4-year (2006–2009) nationwide survey

Objective

The aim of this study was to survey the 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) cancer screening program conducted in Japan.

Methods

The “FDG-PET cancer screening program” included both FDG-PET and positron emission tomography with computed tomography (PET/CT) with or without other combined screening tests that were performed for cancer screening in asymptomatic subjects. A total of 155,456 subjects who underwent the FDG-PET cancer screening program during 2006–2009 were analyzed.

Results

Of the 155,456 subjects, positive findings suggesting possible cancer were noted in 16,955 (10.9 %). The number of cases with detected cancer was 1,912 (1.23 % of the total screened cases, annual range 1.14–1.30 %). Of the 1,912 cases of detected cancer, positive findings on FDG-PET were present in 1,491 cases (0.96 % of the total number of screened cases). According to the results of further examinations, the true positive rate for subjects with suggested possible cancer (positive predictive value) was 32.3 % with FDG-PET. Cancers of the colon/rectum, thyroid, lung, and breast were most frequently found (396, 353, 319, and 163 cases, respectively) with high PET sensitivity (85.9, 90.7, 86.8, 84.0 %, respectively). Prostate cancer and gastric cancer (165 and 124 cases, respectively) had low PET sensitivity (37.0 and 37.9 %, respectively). The Union for International Cancer Control (UICC) clinical stage of cancer found with the FDG-PET cancer screening program was mainly Stage I.

Conclusions

The FDG-PET screening program in Japan has detected a variety of cancers at an early stage. However, several cancers were found in repeated FDG-PET cancer screening program, indicating the limitation of a one-time FDG-PET cancer screening program. The value of the FDG-PET cancer screening program is left to the judgment of individuals with regard to its potentials and limitations.