Inoculation of Rhesus Monkeys with Human Helicobacter pylori: A Long-term Investigation on Gastric Mucosa by Endoscopy

Abstract: To study the pathogenetic role of Helicobacter pylori, colonization of this organism was attempted in conventional rhesus monkeys. After inoculation of human H. pylori to the gastric mucosa of four 10-year-old monkeys, endoscopical and histological examinations were repeated for 10 weeks. The organisms were recovered bacteriologically from all 4 monkeys at the first week, from 3 animals at the 2nd, and from 2 animals at the 6th to 10th week. The endoscopical examination showed only minimum changes in the mucosal appearance such as erythema and erosion due to H. pylori colonization throughout the study. In contrast, the histological examination revealed prominent polymorphonuclear cell infiltration, edema of the mucosa and dissected epithelium at the earlier periods and mononuclear cell infiltration afterwards. The maximum lymphocyte reaction such as clusters or the formation of a thick layer at the bottom of the lamina propria was observed at the 8th week. These results indicated that rhesus monkeys can be infected by human H. pylori resulting in similar pathologic changes in the human stomach, and that this animal model may be useful for future studies.     

Low threshold facilitation of inspiration by lung volume increments

Vagally mediated, volume dependent excitatory effects on phrenic nerve activity have been recently described in anesthetized dogs and pigs, but could not be ascertained in rabbits and baboons (Bartoli et al. 1975, Huszczuk et al. 1977, Cross et al. 1980, Karczewski et al. 1980). Results presented here on cats confirm and further characterize a volume dependent facilitatory effect on inspiratory intercostal and phrenic activity in this species.     

Pyrimethamine Teratogenesis by Short Term Administration in Goettingen Miniature Pig

Pyrimethamine was mixed with mashed feed and given to pregnant sows of Goettingen miniature pig through a part of the period of organogenesis. A high incidence of the major malformations such as cleft palate, club foot and micrognathia was observed in 13 out of 24 newborns from 5 pregnants which a teratogenic dose (3.6 mg/kg of body weight/day) from day 11 to day 22 of gestation, the first half of the organogenetic period. Only one cleft palate was observed among the 23 newborns from 4 pregnants administered the same dose through the second half of the period. Among the 51 newborns from 10 pregnants which the same dose through the first or second quarter, only 4 newborns showed external major malformations. However, 19 out of 38 live newborns without external major malformations in these groups died within 2 days after birth. Clinical symptoms of these neonatally dead young were similar to splayleg, a naturally occurring functional anomaly in pigs. No internal malformation was revealed by the autopsy of these dead newborns.