Fetal and Neonatal Goiter in Cynomolgus Monkeys Following Administration of the Antithyroid Drug Thiamazole at High Doses to Dams During Pregnancy

To evaluate morphologic alterations in the thyroid gland in the second generation in cynomolgus monkeys, pregnant dams were exposed to high doses of thiamazole. In Experiment A, dams received thiamazole intragastrically via a nasogastric catheter from gestation day (GD) 50 to GD 150 or on the day before delivery. Initially, the dose level was 20 mg/kg/day (10 mg/kg twice daily); however, the dose level was subsequently decreased to 5 mg/kg/day (2.5 mg/kg twice daily), since deteriorated general conditions were observed in two dams. Six out of seven neonates died on the day of birth. The cause of neonatal death was tracheal compression and suffocation from goiter. The transplacental exposure to thiamazole affected the fetal thyroid glands and induced goiter in all neonates. The surviving neonate was necropsied 767 days after discontinuation of thiamazole exposure and showed reversibility of the induced changes. In Experiment B, dams were intragastrically administered thiamazole at 5 mg/kg/day (2.5 mg/kg twice daily) for treatment periods from GDs 51 to 70, 71 to 90, 91 to 110, 111 to 130 and 131 to 150. All fetuses showed enlarged thyroid glands but were viable. Histopathologically, hypertrophy and/or hyperplastic appearance of the follicular epithelium of the thyroid gland was observed at the end of each treatment period. The most active appearance of the follicular epithelium, consisting of crowded pedunculated structure, was demonstrated at end of the treatment period from GD 131 to 150. This is the first report on the morphology of fetal and neonatal goiter in the cynomolgus monkey

INFRARED SPECTRA OF HYDRATED CLUSTERS OF GUANINE NUCLEOSIDES OBSERVED BY IR-UV DOUBLE RESONANCE SPECTROSCOPY

Author Institution: Graduate School of Arts and Sciences, Yokohama City University, Yokohama 236-0027, JapanMono- and dihydrated clusters of guanosine and 2'-deoxyguanosine are produced by laser-desorption supersonic-jet cooling and their structures are identified by IR-UV double resonance spectroscopy combined with theoretical calculation. The results show that specific hydration structures around the sugar group exist in both nucleosides., 2009, \textbf{113}, 3455.}, 2009, \textbf{11}, 10466.} It is also demonstrated that the dihydrated structures are strongly influenced by the presence or absence of the 2'-hydroxy group on the sugar