Ulex europeus agglutinin I binding pattern during chemical carcinogenesis in the rat gastrointestinal tract.

BACKGROUND: Fluorescein isothiocyanate-Ulex europeus agglutinin I stain (UEA1) was postulated as a prominent histochemical marker for premalignant mucosa in dimethylhydrazine (DMH)-treated animals. UEA1 (evaluated by two scanning methods) and high iron diamine Alcian blue (HIDAB) stain were used in attempt to detect premalignant colonic mucosa in this animal model. The authors also examined the influence of the duodenal medium on colonic segments transposed to the upper gastrointestinal tract. METHODS: Rats were placed into three groups: those with interposed intestine, those receiving the sham operation, and controls. Half of the animals received DMH, and surviving rats were killed at 2, 4, and 8 months. RESULTS: The authors found no differences in tumor development in the transposed and nontransposed colons of animals treated with DMH. Several transposed segments of animals without carcinogen induction showed dysplastic areas. These findings suggest a trophic role of certain duodenal factors in the epithelial kinetics of the transposed colons. The authors did not find HIDAB stain useful in the identification of premalignant colonic mucosa. The quantitative evaluation method of UEA1 binding was more reliable. Fifteen percent of all the colon specimens of animals without chemical induction were stained with UEA1 with this form of evaluation. Positive staining of the interposed colon samples was the most important factor for these findings. CONCLUSIONS: In this animal model, UEA1 staining is a potentially useful marker of premalignant mucosa, particularly when the nontransposed distal colon of animals treated with DMH is considered.

Influence of VIP on the number of enterochromaffin and mucosal mast cells in the colon of the rat.

The possibility that VIP (Vasoactive intestinal peptide) could influence the enterochromaffin (EC) cell secretion of serotonin (5HT) and the action of VIP on the mast cell population of lamina propria were investigated in Wistar rat colon infused with a short chain fatty acid solution (sodium acetate), during a 1 h period. Under the action of an intravenous injection of synthetic porcine VIP, 14 micrograms/kg/h), the number of EC cells diminished significantly in the cecum and left colon, when compared to non-injected animals, both infused with a sodium acetate solution. At the same time, the number of mucosal mast cells in the crypts and lamina propria decreased significantly in the cecum. The postulate we put forward is that these VIP-induced changes are exerted through the stimulation of 5HT released from EC cells not only under normal physiological conditions but probably also under pathological conditions.

Effects of right hemicolectomy on nitrogen balance in the rat.

Rats with right hemicolectomy were divided into two groups. One group was free-fed (RHFF), the other group pair-fed (RHPF) and both were compared with a group of control animals. The nitrogen balance (NB) was studied for 5 days at 2 and 14 weeks after surgery. The two groups of rats with right hemicolectomy excreted significantly more fecal nitrogen than the control group (p less than 0.01) during the two periods of study. At 2 weeks the RHFF group increased N intake so that their NB was similar to that of the control group. In the same period the nitrogen lost in urine and the NB were reduced in the RHPF rats (p less than 0.01). At 14 weeks the results were similar to those for 2 weeks although the increase in food intake for RHFF and the decrease in NB for RHPF were not statistically significant. The rats with right hemicolectomy showed a decreased gain in body weight. This decrease was more pronounced in the RHPF group. The nitrogen content of the carcass and liver was significantly reduced in the RHPF group 4 months after surgery. It is concluded that the rats with right hemicolectomy were characterized by an increment in the nitrogen lost in feces, and when they were only allowed the same intake of food as the control group, the animals showed marked abnormalities in growth and in the nitrogen content of the organism.

Consideracoes sobre a anatomia do ligamento palpebral lateral. / Anatomy of the lateral eyelid ligament

Os AA. apos apreciarem a importancia do ligamento palpebral lateral na cirurgia plastica e oftalmologica da atualidade, apresenta o resultado de estudo realizado na regiao do canto lateral da orbita. Tal estudo foi efetuado em 46 orbitas de cadaveres de ambos os sexos, onde foi observada a anatomia de ligamento palpebral lateal e tomadas medidas das distancias de seu ponto de insercao em relacao a sutura frontozigomatica. Sao discutidos os resultados e comparados aos de outros autores citados e analisada a aplicabilidade pratica de tais achados

Consideracoes sobre a anatomia cirurgica do ligamento palpebral medial. / Surgical anatomy of the medial palpebral ligament

Os autores apresentaram a situacao atual de reparacao do canto palpebral medial, principalmente quando ha envolvimento do ligamento palpebral medial, e sugerem que um melhor conhecimento da anatomia deste ligamento podera trazer maior eficiencia nas cirurgias desses elementos.E feito estudo anatomico de 60 orbitas de cadaveres dissecados: sao discutidos os resultados e comparados com os da literatura. Referem a necessidade de observacao de que a cada segmento do L.P.M. originam-se diferentes partes do m. orbicular, o que e importante no estabelecimento da conduta e avaliacao dessas cirurgias