68
drug poisoning (especially in drug addicts), but very low when it has been due to cancer ’or acute or chronic infections.8 The paracortical area, adjacent to the postcapillary venules,2,9 often shows a characteristic high cell lining through which lymphocytes are seen migrating. 10 It is an area devoid of lymphoid channels. The cells of this region are composed of small lymphocytes and histiocyte-monocyte macrophages, which produce the starry sky effect when scanty and nodular aggregates when plentiful. Plasma cells and large lymphocytes are not seen in these nodules, which occur in chronic lymphadenitis or reactive hyperplasia and which Ree and Fanger9 found to be much commoner in the superficial glands-cervical, axillary, inguinal-than in the deep mediastinal, abdominal, and retroperitoneal nodes.
Such nodulation may be chiefly of the histiocytic-macrophage cells, and the nodules may become confluent, encroaching on the cortical follicles and the medullary cards and producing the histological picture of dermatopathic lymphadenitis. Such nodules have been termed the " T nodules " by Ree and Fanger,9 who note that, though they share the same paracortical areas with other nodules, they differ in their cell population-which suggests that the T nodule is a local immune reaction associated with some chronic stimulation. It is
becoming
important to specify in lymph-nodes precisely arise and their cell composition. This is causing difficulties in relation to the nodular lymphomas. Thought once to arise from hyperplastic lymphoid follicles," they were later believed to develop at random independently of normal or reactive follicles. 12 Then the idea that they developed from germinal centres was evolved. 13. 14 Certainly the Burkitt looks like a lymphoma malignant germinal centre. ever
more
where the nodules
seen
Levine and Dorfman 15 have studied the relation of nodular lymphomas to germinal centres. They agree that nodular lymphomas develop in close relationship to germinal centres, but could not show that they developed from them and, while the cells of each shared some common characteristics (e.g., nuclear blebs and indentations), their identity could not be established. Dendritic reticulum cells were found in both but were scanty in the nodular lymphomas and no desmosomes were found between the lymphoma cells. The histiocytic cells of nodular lymphomas appeared to be transformed lymphocytes, which throws doubt on the existence of a truly mixed lymphocytic-histiocytic lymphoma. These findings are noted to be somewhat at variance with those of others, and much further work is indicated. It is likely to be fruitful. 7. 8. 9. 10. 11.
Black, M. M., Kerpe, S., Speer, F. D. ibid. 1953, 29, 505. Black, M. M., Dechabon, A. Am. J. clin. Path. 1964, 41, 503. Ree, H., Fanger, H. Hum. Path. 1975, 6, 363. Farr, A. G., De Bruyn, P. P. H. Am. J. Anat. 1975, 143, 59. Brill, N. E., Baehr, G., Rosenthal, N. J. Am. med. Ass. 1925, 84,
12.
Rappaport, H., Winter, W. J., Hicks, E. B. Cancer, N.Y. 1950, 9,
13.
14.
Kojima, M., Imai, Y., Nori, N. Gann. Monograph on Cancer Research. Tokyo, 1973. Lennert, K., Stein, H., Kaiserling, E. Br. J. Cancer, 1975, 31, suppl.
15.
ii, p. 29. Levine, G. D., Dorfman, R. F. Cancer, N.Y. 1975, 35, 148.
668.
ELEMENTAL DIETS
ONE spin-off from the American aerospace programme has been the renewed interest in elemental diets. These are " predigested " foods containing pure aminoacids with minerals, carbohydrates, and vitamins but hardly any fat. They can therefore be absorbed without need for bile, gastric juice, or pancreatic juice. The composition can be precisely defined and they can be readily stored in a powdered form. In astronauts such diets have been used primarily reduce fascal bulk, since practically all the food is absorbed-a property which may be valuable in the preparation of the bowel before colonic surgery and possibly in the treatment of such conditions as ulcerative colitis and Crohn’s disease. Another important indication is gastrointestinal fistula, where mortality has been considerably reduced.1 The elemental diet can be put directly into the distal limb of a smallintestinal fistula or into the intestine below a high fistula. Even in patients with massive (75 %) intestinal resection thesediets can be absorbed, whereas any food needing breakdown by digestive enzymes will In pass through before absorption is complete. an elemental diet has been pancreatic steatorrhoea, successful where the mere addition of pancreatic enzymes has failed. Russell2 suggests other indications, including protein replacement in severe bums and long-term feeding after major oral or dental surgery. In liver disease, elemental diets enable intake to be carefully controlled; and here it is a great advantage to have the carbohydrate and aminoacid parts of the diet packed separately (as with ’Calonutrin’ and to
’Aminutrin’, Gestlich). Will elemental diets then replace parenteral nutrition in seriously ill patients ? Further work is needed, but they certainly are easier to administer, orally or by nasogastric tube, and they bypass the serious complication of sepsis associated with intravenous feeding. Elemental diets may be particularly useful in the treatment of infants in whom it is difficult to set up and maintain an intravenous catheter. Sherman and colleagues3 report excellent results in the treatment of infants with intractable diarrhoea, but they point out that in this age-group it is important to start with a 13% solution, not the 27% recommended for adults (’Vivonex’, Eaton) because of the high osmolality and the risk of hypertonic dehydration.
Elemental diets have some disadvantages. Diarrhoeais owing to the high osmolality-though some manufacturers now claim a low incidence. The earlier preparations were unpalatable, but new flavourings have helped; if the material is being put down a nasogastric tube, there is no problem. Elemental diets will be increasingly used, but they are no magic cure or mysterious new medicine. They are just what their name implies-diets made up of the chemical constituents of food in a form ready to be absorbed rapidly from the intestine. Their use must be based on this understanding. common,
792.
Bury, K. D., Stephens, R. V., Randall, H. T. Am. J. Surg. 1969, 121, 174. 2. Russell, R. I. Gut, 1975, 16, 68. 3. Sherman, J. O., Hamly, C., Khachadurian, A. K. J. Pediat. 1975, 86, 518. 1.
drug poisoning (especially in drug addicts), but very low when it has been due to cancer ’or acute or chronic infections.8 The paracortical area, adjacent to the postcapillary venules,2,9 often shows a characteristic high cell lining through which lymphocytes are seen migrating. 10 It is an area devoid of lymphoid channels. The cells of this region are composed of small lymphocytes and histiocyte-monocyte macrophages, which produce the starry sky effect when scanty and nodular aggregates when plentiful. Plasma cells and large lymphocytes are not seen in these nodules, which occur in chronic lymphadenitis or reactive hyperplasia and which Ree and Fanger9 found to be much commoner in the superficial glands-cervical, axillary, inguinal-than in the deep mediastinal, abdominal, and retroperitoneal nodes.
Such nodulation may be chiefly of the histiocytic-macrophage cells, and the nodules may become confluent, encroaching on the cortical follicles and the medullary cards and producing the histological picture of dermatopathic lymphadenitis. Such nodules have been termed the " T nodules " by Ree and Fanger,9 who note that, though they share the same paracortical areas with other nodules, they differ in their cell population-which suggests that the T nodule is a local immune reaction associated with some chronic stimulation. It is
becoming
important to specify in lymph-nodes precisely arise and their cell composition. This is causing difficulties in relation to the nodular lymphomas. Thought once to arise from hyperplastic lymphoid follicles," they were later believed to develop at random independently of normal or reactive follicles. 12 Then the idea that they developed from germinal centres was evolved. 13. 14 Certainly the Burkitt looks like a lymphoma malignant germinal centre. ever
more
where the nodules
seen
Levine and Dorfman 15 have studied the relation of nodular lymphomas to germinal centres. They agree that nodular lymphomas develop in close relationship to germinal centres, but could not show that they developed from them and, while the cells of each shared some common characteristics (e.g., nuclear blebs and indentations), their identity could not be established. Dendritic reticulum cells were found in both but were scanty in the nodular lymphomas and no desmosomes were found between the lymphoma cells. The histiocytic cells of nodular lymphomas appeared to be transformed lymphocytes, which throws doubt on the existence of a truly mixed lymphocytic-histiocytic lymphoma. These findings are noted to be somewhat at variance with those of others, and much further work is indicated. It is likely to be fruitful. 7. 8. 9. 10. 11.
Black, M. M., Kerpe, S., Speer, F. D. ibid. 1953, 29, 505. Black, M. M., Dechabon, A. Am. J. clin. Path. 1964, 41, 503. Ree, H., Fanger, H. Hum. Path. 1975, 6, 363. Farr, A. G., De Bruyn, P. P. H. Am. J. Anat. 1975, 143, 59. Brill, N. E., Baehr, G., Rosenthal, N. J. Am. med. Ass. 1925, 84,
12.
Rappaport, H., Winter, W. J., Hicks, E. B. Cancer, N.Y. 1950, 9,
13.
14.
Kojima, M., Imai, Y., Nori, N. Gann. Monograph on Cancer Research. Tokyo, 1973. Lennert, K., Stein, H., Kaiserling, E. Br. J. Cancer, 1975, 31, suppl.
15.
ii, p. 29. Levine, G. D., Dorfman, R. F. Cancer, N.Y. 1975, 35, 148.
668.
ELEMENTAL DIETS
ONE spin-off from the American aerospace programme has been the renewed interest in elemental diets. These are " predigested " foods containing pure aminoacids with minerals, carbohydrates, and vitamins but hardly any fat. They can therefore be absorbed without need for bile, gastric juice, or pancreatic juice. The composition can be precisely defined and they can be readily stored in a powdered form. In astronauts such diets have been used primarily reduce fascal bulk, since practically all the food is absorbed-a property which may be valuable in the preparation of the bowel before colonic surgery and possibly in the treatment of such conditions as ulcerative colitis and Crohn’s disease. Another important indication is gastrointestinal fistula, where mortality has been considerably reduced.1 The elemental diet can be put directly into the distal limb of a smallintestinal fistula or into the intestine below a high fistula. Even in patients with massive (75 %) intestinal resection thesediets can be absorbed, whereas any food needing breakdown by digestive enzymes will In pass through before absorption is complete. an elemental diet has been pancreatic steatorrhoea, successful where the mere addition of pancreatic enzymes has failed. Russell2 suggests other indications, including protein replacement in severe bums and long-term feeding after major oral or dental surgery. In liver disease, elemental diets enable intake to be carefully controlled; and here it is a great advantage to have the carbohydrate and aminoacid parts of the diet packed separately (as with ’Calonutrin’ and to
’Aminutrin’, Gestlich). Will elemental diets then replace parenteral nutrition in seriously ill patients ? Further work is needed, but they certainly are easier to administer, orally or by nasogastric tube, and they bypass the serious complication of sepsis associated with intravenous feeding. Elemental diets may be particularly useful in the treatment of infants in whom it is difficult to set up and maintain an intravenous catheter. Sherman and colleagues3 report excellent results in the treatment of infants with intractable diarrhoea, but they point out that in this age-group it is important to start with a 13% solution, not the 27% recommended for adults (’Vivonex’, Eaton) because of the high osmolality and the risk of hypertonic dehydration.
Elemental diets have some disadvantages. Diarrhoeais owing to the high osmolality-though some manufacturers now claim a low incidence. The earlier preparations were unpalatable, but new flavourings have helped; if the material is being put down a nasogastric tube, there is no problem. Elemental diets will be increasingly used, but they are no magic cure or mysterious new medicine. They are just what their name implies-diets made up of the chemical constituents of food in a form ready to be absorbed rapidly from the intestine. Their use must be based on this understanding. common,
792.
Bury, K. D., Stephens, R. V., Randall, H. T. Am. J. Surg. 1969, 121, 174. 2. Russell, R. I. Gut, 1975, 16, 68. 3. Sherman, J. O., Hamly, C., Khachadurian, A. K. J. Pediat. 1975, 86, 518. 1.
