Search

Antivenom reactions are a common complication of snake antivenom. This study aimed to identify predicators of antivenom reaction and the involvement of antivenom skin test in antivenom reaction development. This retrospective cohort study was conducted in six medical institutions in Taiwan. Data were extracted from the Chang Gung Research Database (CGRD) from January 2006 to December 2016. The association between antivenom reaction and patient demographics, type and dose of antivenom, and skin test results was analyzed. The study enrolled 799 patients, including 219 who developed antivenom reactions. Compared to patients receiving both freeze-dried hemorrhagic (FH) and freeze-dried neurotoxic (FN) antivenom, those administered a single type had a lower antivenom reaction risk (adjusted odds ratios [aORs]: 0.5 and 0.4, 95% confidence interval [CI]: 0.35–0.74 and 0.24–0.69, FH and FN respectively). Patients administered a higher antivenom dose (≥ 5 vials) had higher antivenom reaction risk (aOR: 1.8, 95% CI: 1.23–2.76). A positive skin test result was also associated with antivenom reaction (aOR: 16.7, 95% CI: 5.42–51.22). The skin test showed high specificity (98.5%, 95% CI: 97.49%–99.83%) but low sensitivity (17.5%, 95% CI: 10.74%–24.18%). The antivenom skin test should be abolished because of the extremely low sensitivity and possible misinterpretation of results because of the limitation of this examination. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: [123I]Epidepride is a radio-tracer with very high affinity for dopamine D2/D3 receptors in brain. The importance of alteration in dopamine D2/D3 receptor binding condition has been wildly verified in schizophrenia. In the present study we set up a rat schizophrenia model by chronic injection of a non-competitive NMDA receptor antagonist, MK-801, to examine if [123I]epidepride could be used to evaluate the alterations of dopamine D2/D3 receptor binding condition in specific brain regions. Method: Rats were given repeated injection of MK-801 (dissolved in saline, 0.3mg/kg) or saline for 1month. Afterwards, total distance traveled (cm) and social interaction changes were recorded. Radiochemical purity of [123I]epidepride was analyzed by Radio-Thin-Layer Chromatography (chloroform: methanol, 9:1, v/v) and [123I]epidepride neuroimages were obtained by ex vivo autoradiography and small animal SPECT/CT. Data obtained were then analyzed to determine the changes of specific binding ratio. Result: Chronic MK-801 treatment for a month caused significantly increased local motor activity and induced an inhibition of social interaction. As shown in [123I]epidepride ex vivo autoradiographs, MK-801 induced a decrease of specific binding ratio in the striatum (24.01%), hypothalamus (35.43%), midbrain (41.73%) and substantia nigra (37.93%). In addition, [123I]epidepride small animal SPECT/CT neuroimaging was performed in the striatum and midbrain. There were statistically significant decreases in specific binding ratio in both the striatum (P <.01) and midbrain (P <.05) between the saline and MK-801 group. Conclusion: These results suggest that [123I]epidepride is a useful radio-tracer to reveal the alterations of dopamine D2/D3 receptor binding in a rat schizophrenia model and is also helpful to evaluate therapeutic effects of schizophrenia in the future. [Copyright &y& Elsevier]

Abstract: [18F]Flurobutyl ethacrynic amide ([18F]FBuEA) was prepared from the precursor tosylate N-Boc-N-[4-(toluenesulfonyloxy)butyl]ethacrynic amide with a radiochemical yield of 3%, a specific activity of 48GBq/μmol and radiochemical purity of 98%. Chemical conjugation of [18F]FBuEA with glutathione (GSH) via a self-coupling reaction and enzymatic conjugation under catalysis of glutathiontransferase alpha (GST-α) and π provided about 41% yields of radiochemical conjugated product [18F]FBuEA–GSH, 85% and 5–16%, respectively. The catalytic selectivity of this tracer toward GST-alpha was addressed. Positron emission tomography (PET) imaging of [18F]FBuEA in normal rats showed that a homogeneous pattern of radioactivity was distributed in the liver, suggesting a catalytic role of GST. By contrast, PET images of [18F]FBuEA in rats with thioacetamide-induced cholangiocarcinoma displayed a heterogeneous pattern of radioactive accumulation with cold spots in tumor lesions. PET imaging with [18F]FBuEA could be used for early diagnosis of hepatic tumor with a low GST activity as well as liver function. [Copyright &y& Elsevier]

Abstract: This study is concerned with the development of an agent for single photon emission computer tomography (SPECT) for imaging inflammation and tumor progression. [123I]Iodooctyl fenbufen amide ([123I]IOFA) was prepared from the precursor N-octyl-4-oxo-4-(4′-(trimethylstannyl)biphenyl-4-yl)butanamide with a radiochemical yield of 15%, specific activity of 37 GBq/μmol, and radiochemical purity of 95%. Analysis of the binding of [123I]IOFA to COX-1 and COX-2 enzymes by using HPLC and a gel filtration column showed a selectivity ratio of 1:1.3. An assay for the competitive inhibition of substrate transfer showed that IOFA exhibited a comparable IC50 value compared to fenbufen. In the normal rat liver, a lower level and homogeneous pattern of [123I]IOFA radioactivity was observed by SPECT. In contrast, in the rat liver with thioacetamide-induced cholangiocarcinoma, a higher uptake and heterogeneous pattern of [123I]IOFA radioactivity was seen as hot spots in tumor lesions by SPECT imaging. Importantly, elevated COX-1 and COX-2 expressions from immunostaining were found in the bile ducts of tumor rats but not of normal rats. Therefore, [123I]IOFA was found to exhibit the potential for imaging tumors that over-express COX. [Copyright &y& Elsevier]

Abstract: Changes in regional metabolic activities induced by middle cerebral artery occlusion (MCAO) can influence patient outcome. Our aim was to demonstrate in a rat model that 18F-FDG with positron emission tomography (PET) imaging is a quantitative, reproducible approach for identifying acute and sub-acute metabolic variations in infarct regions. We found that imaging with 18F-FDG/PET enabled detection and quantification of ischemia-induced metabolic deficits and provided a sensitive and reliable means of assessing cerebral ischemic lesions compared with conventional neurological scoring systems in rodents. [Copyright &y& Elsevier]