OBJECTIVE: Animal experiments were conducted to test the reproducibility of previously documented antiteratogenic effects of thiamine on cleft formation in the craniofacial system. DESIGN: Thirteen gravid Wistar rats carrying 98 fetuses were given the hydrazine derivative procarbacine (200 mg/kg BW) on the fourteenth day postconception (PC) to induce malformations, chiefly cleft alveolus and palate (day of determining presence of sperm was called the first day PC). Seven of the treated gravid rats carrying 48 fetuses were additionally given a daily dose of 200 mg/kg thiamine from the thirteenth to the nineteenth day PC. OUTCOME MEASURES: A comparative analysis of the fetuses in both experimental groups was conducted externally and, for the skeleton, macroscopically using special staining techniques; the heads were analyzed using successional histologic sections; bodies were examined stereomicroscopically using the razor-blade sectioning technique. RESULTS: In 12 of the 16 parameters evaluated, no statistically significant differences were found between experimental groups. In some cases, we even observed an amplifying effect of thiamine on the development of malformations in the rat strain used in our study. CONCLUSIONS: Because several previous authors have repeatedly described treatment with thiamine as one of the sufficient prophylactic measures in slowing the development of viscerocranial malformations, especially cleft alveolus and palate, it is of utmost importance that the timing of treatment and dosage of thiamine be taken into consideration not only in animal experiments but also when applying results to humans.
OBJECTIVE: Animal experiments were conducted to test the reproducibility of previously documented antiteratogenic effects of thiamine on cleft formation in the craniofacial system. DESIGN: Thirteen gravid Wistar rats carrying 98 fetuses were given the hydrazine derivative procarbacine (200 mg/kg BW) on the fourteenth day postconception (PC) to induce malformations, chiefly cleft alveolus and palate (day of determining presence of sperm was called the first day PC). Seven of the treated gravid rats carrying 48 fetuses were additionally given a daily dose of 200 mg/kg thiamine from the thirteenth to the nineteenth day PC. OUTCOME MEASURES: A comparative analysis of the fetuses in both experimental groups was conducted externally and, for the skeleton, macroscopically using special staining techniques; the heads were analyzed using successional histologic sections; bodies were examined stereomicroscopically using the razor-blade sectioning technique. RESULTS: In 12 of the 16 parameters evaluated, no statistically significant differences were found between experimental groups. In some cases, we even observed an amplifying effect of thiamine on the development of malformations in the rat strain used in our study. CONCLUSIONS: Because several previous authors have repeatedly described treatment with thiamine as one of the sufficient prophylactic measures in slowing the development of viscerocranial malformations, especially cleft alveolus and palate, it is of utmost importance that the timing of treatment and dosage of thiamine be taken into consideration not only in animal experiments but also when applying results to humans.