Enzyme-histochemical study on the fine distribution of the intramural lymphatics at the ileocecal junction of the monkey intestine

Lymphatics in the alimentary tract of children in health and disease: study on mucosal biopsies using the monoclonal antibody d2-40

Primary intestinal lymphangiectasia and intestinal lymphatic hypoplasia are 2 causes of protein-losing enteropathy in children and share many common clinical features. For the diagnosis of lymphatic hypoplasia on endoscopic biopsies of the intestine, i.e., based on a negative finding in a small specimen, a very sensitive and specific method for identifying lymphatics is essential. In the present study, lymphatic vessels were labelled using D2-40 immunostaining in mucosal biopsy specimens of the alimentary tract of children in whom no histologic abnormality was noted and of those who had different relatively common pediatric conditions, including inflammatory and neoplastic diseases. Using this method, lymphatic vessels were well visualized even in young infants and not destroyed by diseases. The presence of the muscularis mucosae in specimens was important for adequate assessment. In the duodenum and esophagus, lymphatics were observed in every single section; in the stomach, ileum, and colon, they were less regular and several sections were sometimes required. The extreme sensitivity of this method for demonstrating lymphatic vessels in the duodenum makes it ideal for the histologic diagnosis of intestinal lymphatic hypoplasia. In 4 patients who were considered to have this diagnosis based on clinical features, full-thickness intestinal biopsies and electron microscopy, D2-40 immunostaining confirmed the absence or marked paucity of lymphatics.

Lymphatic corrosion casts in rabbit ileum: scanning electronmicroscopic studies

AIM

To investigate the three-dimensional organization and fine distribution of the lymphatics in rabbit ileum.

METHODS

Lymphatic corrosion cast with the Mercox were used for scanning electron microscopy (SEM), and semithin sections were used for light microscopy. The Mercox injected intraparenchymally into ileum wall were cut and put in a concentrated NaOH solution until the tissues were corroded away, and observed under SEM.

RESULTS

The central lacteals were found in the intestinal villi. The villi of the ileum contained two to three lacteals. The central lacteals were drained into the mucosal lymphatic capillary plexus. From the plexus, the lymphatic capillary descended into the lymphatics of submucosal layer and muscular layer. Then they were led into the serosal lymphatics and drained into the lymphatics of intestine mesentery. The cast of the lymphatics showed an appearance of a string of heads and the notch corresponding to the bicuspid valve of the lymphatics.

CONCLUSION

The three-dimensional organization of central lacteals and lymphatics in the rabbit ileum is demonstrated by lymphatic corrosion casts. Numerous impressions of the endothelial nuclei, rich central lacteals and lymphatic capillary plexus in the ileum mucosa, lymphatic capillary and lymphatics in the submucosa and muscular layer are observed on the lymphatic corrosion cast.

Mucin histochemical analysis of the ileocaecal valve and lymphoid tissues of the terminal ileum: role against tumour invasion

OBJECTIVES

We previously reported clinicopathological data on 78 patients who underwent a right hemicolectomy from 1990 to 1997. Our results indicated that the ileocaecal valve [ICV] and lymphoid tissue of the terminal ileum might, together, play a protective and local immune role against carcinoma invasion. Furthermore, we previously reported that mucin histochemical features of the transitional zone [TZ] might also play a role in predicting metastasis and, thus, prognosis. The aim of this study was to examine the clinicopathological correlation between lymphoid infiltration and mucin secretion in the terminal ileum with carcinoma of the right colon.

METHODS

According to the proximity of the tumour to the ICV, a total of 16 specimens with lymphoid infiltration to and around [< 1 cm] the ICV were studied in order to identify the mucin expression and histochemical features of the TZ as a prognostic indicator.

RESULTS

Patients with sulphomucin-staining tumours in the terminal ileum and ICV had a relatively favourable course. Even when the clinical staging was the same for different tumours, greater lymphoid infiltration in the ICV, greater staining for sulphomucin in the ICV and a relatively favourable course were observed in nine patients. The sulphomucin-type TZ showed a favourable course as well. On the other hand, patients with sialomucin staining of the ICV and the TZ tended to have low-grade lymphoid infiltration and a very poor course, although two patients with moderately high-grade lymphoid infiltration had a favourable course. Overall survival was significantly associated with the mucin type of the ICV [p < 0.01].

CONCLUSIONS

Our results indicated that lymphoid infiltration of the terminal ileum may lead to an alteration in mucin secretion and, thus, play a protective role in the invasive and metastatic process of advanced right colon carcinoma.

Eyelid lymphatics I: histochemical comparisons between the monkey and human

PURPOSE

To study the lymphatic drainage of the cynomolgus monkey and human eyelid and periocular tissue by means of histochemistry.

METHODS

Eyelid and periocular tissue from three cynomolgus monkeys undergoing sacrifice for glaucoma and retina research purposes and discarded tissue from a wedge resection of one human eyelid were used for histochemical analysis. Lymphatic capillaries were distinguished histochemically in monkey and human eyelids by light microscopy with a 5'-nucleotidase (5'-Nase) staining method. Identification of lymphatic vessels was based on strict morphologic criteria combined with specific 5'-Nase staining.

RESULTS

Histochemical analysis with 5'-nucleotidase revealed a subcutaneous and pretarsal lymphatic plexus in both the human and monkey.

CONCLUSIONS

Histochemical results demonstrate similar lymphatic plexi in the monkey and human. Future studies will help to clarify the lymphatic drainage pathways of monkey and human eyelids.