Morphological changes induced by cyclophosphamide in crypt epithelium of the small intestine in mice: light and electron microscopic studies

Gastrointestinal toxicity of chemotherapeutic agents

Chemotherapy-induced toxicities commonly occur in sites within the gastrointestinal (GI) tract and account for dose-limiting effects. These toxicities are major contributing factors to dose reduction, delays, and cessation of cancer treatment. Through intensive therapies including surgery, combination chemotherapy, hormonal therapy, and targeted therapy, an increasing number of patients with cancer are experiencing improved survival and long-term disease-free survival, as well as palliation of disease-related symptoms. Thus, GI toxicities should be predicted and appropriate interventions initiated to prevent them when possible and provide effective supportive measures and comprehensive follow-up care. This review will discuss the etiology, incidence, prevention, and treatment of GI toxicities of cancer chemotherapy.

Effects of the aqueous extract of Epimedii Herba on the induction of oral tolerance in mice

We investigated the effects of the aqueous extract of Epimedii Herba (AEEH) on the induction of oral tolerance. Oral tolerance was induced in mice by giving an oral administration of 20 mg ovalbumin (OVA) 7 d before immunization with the antigen. AEEH at 40 mg/kg was given orally daily for 6 d from 24 h after the feeding of OVA. The results showed that oral administration of OVA greatly suppressed total serum and antigen-specific immunoglobulin (Ig) levels, phagocytic activity and delayed-type hypersensitivity (DTH) reaction to the antigen. The suppression of these immune responses to OVA by the oral antigen was associated with a marked reduction of the production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) from spleen cells. However, AEEH treatment significantly blocked the suppression of total serum and antigen-specific IgG2a antibodies, phagocytic activity and DTH response by the oral OVA. The suppression of IFN-y production by the oral antigen was also greatly decreased by AEEH treatment. Therefore, AEEH appears to be effective in preventing the induction of oral tolerance to OVA.

Impact of antitumor therapy on nutrition

Surgery, radiation, and chemotherapy can result in further deterioration in nutritional status in patients who are frequently malnourished as a consequence of their underlying malignancy. Many of the effects are transient, and patients who have a good performance status may exhibit minimal alterations in nutritional parameters during the course of treatment. However, antitumor treatment may enhance morbidity, and in some, it leads to mortality if patients are in poor nutritional status ab initio. Such malnourished patients must be recognized prior to initiation of treatment, and steps must be taken to maintain adequate nutrition. The known toxic effects of many cancer therapeutic regimens must be weighed against their potential benefits.

Effect of cyclophosphamide on the proliferation of L 1210 ascites tumour cells and of jejunal crypt cells in the mouse

Cyclophosphamide (CY) does not act in a cell-cycle specific manner, i.e. exclusively on proliferating cells. It also kills non-proliferating cells, as shown by application of CY to L 1210 ascites tumour-bearing mice during plateau phase growth of the tumour. Moreover, treatment with CY of L 1210 ascites tumour cells, double-labelled with [3H] and [14C]-thymidine, suggests that CY is not cell cycle phase dependent, but kills cells out of all cycle phases. There is also an extensive cytocidal effect of CY (300 mg/kg) on the jejunal crypt cells of the mouse, which is even more pronounced than that of cisplatinum (DDP, 13 mg/kg). However, rapid regeneration of crypt cells occurs after treatment with the drugs.

Intestinal changes caused by DL-alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase

Subacute (2 week) oral or intravenous administration of DL-alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), caused diarrhea and frequent emesis as early as 4 to 5 days in dogs (dose greater than or equal to 200 mg/kg/day). Diarrhea also occurred in monkeys after 1 week of treatment with an intravenous dose of 1000 mg/kg/day. Especially evident in the treated dogs with diarrhea were fluid loss, hemoconcentration, and decreased serum sodium and chloride which were findings totally reversible about 2 weeks after cessation of dosing. As a result of treatment with the highest intravenous dosage (1000 mg/kg/day), villous atrophy of the mucosa was observed by light and scanning electron microscopy in the canine small intestine. Transmission electron microscopy demonstrated that the most significant alterations of the canine intestinal tract involved the microvilli of epithelial cells which became shorter and were frequently less numerous or absent along focal areas of the plasma membrane. Intestinal mucosal levels of putrescine, especially in the duodenum and jejunum, were decreased as demonstrated in the monkeys following intravenous treatment with 100, 300, or 1000 mg/kg/day of DFMO. The results of this investigation are consistent with the hypothesis that the inhibition of ODC activity and subsequent altered polyamine metabolism may lead to delayed maturation of the intestinal epithelial cells and the impaired development of their microvilli, causing fluid loss due to reduced absorptive surface area.

Ultrastructure of macrophages and karyolytic bodies in small intestinal villi of macaque monkeys and baboons

Macrophages in the lamina propria at the tips of small intestinal villi in 41 of 51 macaque monkeys were filled with eosinophilic, autofluorescent, periodic acid-Schiff-positive globules, hematoxyphilic and Feulgen-positive granules, vacuoles, and iron and lipochrome pigments. The Feulgen-positive granules were seen ultrastructurally in macrophages of nine of 15 clinically normal macaques and baboons. Four of the 15 had similar granules in the intercellular spaces of the epithelium. Ultrastructurally, the eosinophilic globules were electron-dense phagolysosomes; the Feulgen-positive granules resembled nuclei of lymphocytes in various stages of pyknosis. Cytoplasmic organelles enclosed in membrane-bound vacuoles were present in the intercellular spaces of the epithelium of one monkey. Similar organelles were phagocytized by macrophages in another monkey. Feulgen-positive granules have been reported in villi of normal rodents. In all other species, including man, degenerating nuclei called "karyolytic bodies" and other evidence of enterocyte or lymphocyte degeneration have been considered abnormal concomitants of irradiation and antimitotic therapy. The significance of the findings in monkeys is not known, but they may represent a subclinical disease process.