Biomedical subjects

J G Sharp

Publications and source records attributed to J G Sharp.

At least 19 recordsLinked to original sources

PubMed1992

OMA-AML-1: a leukemic myeloid cell line with CD34+ progenitor and CD15+ spontaneously differentiating cell compartments.

OMA-AML-1 was established from a patient with acute myelomonocytic (M4) leukemia at fifth relapse when blasts were greater than 85% CD34+, CD15-. Leukemic cells were established in suspension culture and independently grown as subcutaneous tumors in SCID mice. Cells growing in suspension culture underwent differentiation by phenotypic and morphologic criteria. In contrast, cells grown as subcutaneous solid tumors in SCID mice maintained progenitor cell characteristics with high-density CD34 expression and lack of morphologic differentiation. A tendency toward differentiation to CD15+, CD34- cells in vitro and self-renewal of CD34+, CD15- cells in vivo was consistently demonstrated regardless of whether cells were initially grown in vitro or in vivo. The cell line maintains both a CD34+, CD15- progentitor cell pool and a non-overlapping, CD15+, CD34- differentiating cell compartment after more than 1 year in continuous culture. Cell cycle analysis and cloning experiments were consistent with terminal differentiation occurring in the CD15+, CD34- population. The cell line shows concentration-dependent proliferative responses to interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-6, but not to granulocyte CSF (G-CSF). OMA-AML-1 appears to mimic several features of normal myeloid hematopoiesis and should prove useful for the study of normal and malignant myeloid differentiation.

Animals↗

PubMed1992

Significance of detection of occult non-Hodgkin's lymphoma in histologically uninvolved bone marrow by a culture technique.

Prolonged disease-free survival of patients with recurrent or resistant non-Hodgkin's lymphoma (NHL) has been achieved with high-dose therapy followed by autologous bone marrow transplantation (ABMT). A concern with the use of ABMT is that the marrow that is reinfused may contain undetected NHL cells with the potential to reestablish metastatic disease in the recipient. Using a culture technique that is sensitive for detecting occult lymphoma cells in BM, we analyzed histologically normal marrow harvests from 59 consecutive patients with intermediate- or high-grade NHL who were candidates for high-dose therapy and ABMT. The culture results indicated that 22 of the patients had occult lymphoma in their marrow. Forty-three patients underwent high-dose therapy followed by ABMT. Twenty-four achieved a complete clinical remission. Those with occult lymphoma in their harvests (11 patients) continued to relapse for up to 3 years, whereas no relapses were observed beyond 8 months in 13 patients receiving marrow that did not contain detectable lymphoma cells using the culture technique. The relapses in the patients who achieved a complete remission occurred at sites of prior bulky disease rather than at new sites, suggesting that the ability to detect occult lymphoma cells in marrow is a marker of biologic aggressiveness and/or resistance to therapy, or that the reinfused cells could only grow in previously involved sites. The detection of lymphoma cells in marrow used for ABMT is an important adverse prognostic factor, and appears to be independent of other clinical predictors of outcome such as sensitivity or resistance of disease to prior chemotherapy.

Adolescent↗

PubMed1992

Immunohistological characterization of proximal colonic lymphoid tissue in the rat.

Proximal colonic lymphoid tissue (PCLT) is a lymphoid structure located in the proximal colon of the mouse and the rat. In the present investigation we studied the immunomorphology and cytology of PCLT in the rat. We also studied sites of lymphocyte proliferation using the BrdU-anti BrdU technique. Results demonstrated no evident phenotypical differences between the lymphocyte populations of PCLT and either jejunal or ileal Peyer's patches (PP). The majority of the lymphocytes within PCLT were B cells localized in follicles, which were separated from each other by interfollicular T cell areas. Germinal centers (GC), containing ED5+ follicular dendritic cells, are found within PCLT follicles. The T cell areas contained both MHC Class II+ interdigitating cells and high endothelial venules. Studies using BrdU-anti BrdU indicated that lymphocyte proliferation within PCLT takes place mainly in germinal centers. Together the data show that the organization, lymphoid constituents, and sites of lymphocyte production are very similar in PCLT and PP. We therefore conclude that PCLT in the rat is not a Bursa equivalent, but more likely a PP with some special characteristics.

Animals↗

PubMed1992

Collection of blood mononuclear cells by leukapheresis for transplantation in a Yucatan miniature swine model.

A large animal model is needed to evaluate new apheresis technologies. These technologies include novel methods of harvesting the blood mononuclear cell population which contains the hematopoietic stem cells needed to restore hematopoiesis in recipients of hematopoietically lethal therapy and the use of cytokines to provide a safe and predictable method of manipulating these circulating hematopoietic stem cells. We describe the methods used to collect mononuclear cells by leukapheresis from Yucatan miniature swine. These animals are of sufficient size to tolerate the procedures and have many physiologic and hematologic similarities to man. They are of good temperament and are easily trained. Long-term venous access was obtained using single lumen silicone rubber catheters placed in the inferior vena cava. The animals were apheresed while fully awake using a Haemonetics Model V50 machine and a modified lymphocyte collection protocol. The procedure was highly efficient for the collection of mononuclear cells and a 10 pass procedure yielded a product which contained 19.7 x 10(9) mononuclear cells, 10.7 x 10(9) granulocytes, and 17 ml of erythrocytes in a volume of approximately 100 ml. This product can be cryopreserved and used for subsequent transplantation. The content of four apheresis procedures provides hematopoietic reconstitution of lethally irradiated swine on a time scale equivalent to transplantation of optimal numbers of bone marrow cells.

Animals↗

PubMed1992

Basement membrane components enhance isolated enterocyte growth.

Isolated enterocyte transplantation may have a potential role in increasing intestinal surface area. However, enterocytes are notoriously difficult to grow. Basement membrane components (BMC) promote adherence, migration, and differentiation of enterocytes. Our aim was to determine if BMC enhance enterocyte growth. Twenty-nine rabbits had 5-cm ileal segments resected and serosal pouches (n = 22) created from the serosal surface of the colon. Harvesting of enterocytes by warm trypsinization resulted in 92 +/- 6% cell viability and yielded 5.0 +/- 2.4 10(6) enterocytes/cm intestine. Enterocytes (10(5) were cultured in vitro (n = 7) in 10 ml growth media in plain flasks and flasks coated with laminin alone or Matrigel (an extract of mouse basement membrane containing laminin plus Type IV collagen and heparan sulfate). The cells were subcultured at 2 weeks and examined after Geimsa staining at 4 weeks. Epithelial growth was confirmed by light microscopy and staining for cytokeratin and quantitated by image analysis (JAVA). Epithelial coverage of the flasks was greater with Matrigel (80 +/- 15%) than laminin (66 +/- 15%) which was greater than control (44 +/- 20%) (P less than 0.01). For in vivo studies 10(5) harvested cells were infused into the serosal pouches either in growth media (n = 9) or media + Matrigel (n = 13). Epithelial growth in the pouch was evaluated by qualitative scoring of cytokeratin staining. Cytokeratin staining was similar on control colon serosa (n = 5) and serosa after infusion of cells in media alone. However, Matrigel significantly enhanced the area, depth, and intensity of staining.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Association of radiolabeled urogastrone binding with regenerating intestinal mucosa and epidermal growth factor/urogastrone producing organs in rat.

In the present study, we have tested the hypothesis that the regeneration of intestinal epithelium is regulated by changes in the uptake of radiolabeled recombinant human urogastrone (125I rhUG) in the regenerating mucosa and epidermal growth factor/urogastrone (EGF/URO) producing organs in the rats. Operations were performed on rats to approximate the ileal mucosa to the serosal surface of the cecum. This procedure allows the regeneration of ileal mucosa onto the serosal surface of the cecum. Groups of 5 rats were killed on the 2nd, 4th, 8th and 12th post-operative days. Two hours before autopsy, rats were given 0.5 ml (50 microCi with 30 micrograms protein) of 125I rhUG intravenously and the following tissues were removed: regenerating mucosa, salivary gland, duodenum, liver and kidney. Results indicated that the uptake of 125I rhUG was significantly greater in the salivary gland and duodenum on the 2nd post-operative day which gradually tapered with increasing time after surgery. A similar pattern in the uptake of 125I rhUG was also evident in the regenerating mucosa. Further analysis revealed a significant correlation between the uptake of 125I rhUG in the salivary gland and duodenum vs rate of epithelialization and uptake of 125I rhUG in the regenerative mucosa. These results suggested that the endogenous EGF/URO produced in the salivary gland and duodenum may be a factor in the regulation of intestinal regeneration; however, the mechanism responsible for reflex stimulation of EGF/URO production in these organs is not known.

Animals↗

PubMed1992

Quantitation of metastatic tumor burden from human colon tumor xenografts using radiolabelled monoclonal antibody 17-A fragments.

In realistic models of human tumor xenograft metastasis, the metastatic foci arise in perivascular sites and rarely grow to sizes which are easily quantifiable by visual inspection. As an alternative approach, we have used monoclonal antibody (MAb) 17-1A F(ab')2 fragments labelled with radioiodine (125I) to study the differential accumulation of label in xenografts and metastatic tumor sites as well as in noninvolved tissues of NIH Swiss nude mice receiving HT-29 human colon tumor cells. Images of the whole-body distribution and sites of localization were determined using a pinhole-collimated Angergamma camera. Radioactivity was determined in tissue samples using a well scintillation system, and pharmacokinetics were assessed during the initial 72 h after injection of antibody fragments. The half-life of 125I-F(ab')2 fragments in the blood, 8.6 h, was similar in nontumor-bearing control and tumor-bearing mice. The half-life in subcutaneous tumor xenografts was 30.1 h. The tumor xenograft to tissue activity ratios per unit weight (radiolocalization indices) at 72 h were: blood 90, lung 65, pancreas 50, muscle 35, spleen 20, liver and mesenteric lymph node 10. All subcutaneous xenografts were successfully imaged, and images of 5 of 9 mice (55%) appeared to demonstrate the presence of metastatic tumor by differential and focal accumulation of MAb fragments after 48 or 72 h in the lung (2 cases) or abdominal cavity (3 cases). Necropsy and subsequent histological and biodistribution studies confirmed the presence of metastatic tumor in these sites and identified tumor in several additional sites. The smallest volume of metastatic tissue in liver or lung determined at necropsy which appeared to have been detected by imaging was about 20 mm3. Generally, for mice with metastatic tumors, the radioactivity per unit weight of metastatic tumor-bearing organs compared to tumor-free organs was 2- to 7-fold greater. The results indicate that a radiolocalization index of > or = 2 is generally necessary for metastatic tumor detection by imaging although this is influenced by the extent of anatomical location of the tumor. It was possible to predict the tissue distribution of the fragments from the planar image for the amounts of radioactivity (approximately 1 mCi/kg body weight) employed in this study. These results demonstrate the utility of this approach to quantitate the metastatic burden arising from human colon tumor xenografts in this experimental model.

Animals↗

PubMed1992

Chronic catheterization of the inferior vena cava in Yucatan miniature swine.

Long-term venous access for leukapheresis, repeated blood sampling, and administration of drugs and fluids can be accomplished nonsurgically in Yucatan miniature swine. The catheter is placed under fluoroscopic guidance into the inferior vena cava using a needle and guidewire. This procedure has the advantage that it avoids a surgical incision, allows high flow rates, exists conveniently on the lower back, and can be replaced easily in the event of mechanical failure or thrombosis. Actuarial analysis of the duration of patency disclosed that of 41 catheters placed in 30 animals, the probability of function at 28, 42, and 54 days was 75%, 50%, and 25%, respectively. Eleven nonfunctioning catheters were replaced and nine of these continued to function until the completion of the experiment. No catheters were removed due to infection. Chronic catheterization of the inferior vena cava is a convenient method for long-term venous access in swine.

Animals↗

PubMed1992

Role of epidermal growth factor in intestinal regeneration.

We have quantitated uptake of radiolabeled recombinant human urogastrone/epidermal growth factor (125I rhUG/EGF), crypt cell production rate, and rate of epithelialization on days 2, 4, 8, and 12 after operation in the ileum, mucosa adjacent to the wound, and neomucosa (regenerating mucosa) during healing of a full-thickness ileal defect in rats. The uptake of 125I rhUG/EGF in adjacent mucosa and neomucosa was highest on the day 2 (0.64% +/- 0.1% and 0.98% +/- 0.14% injected dose/gm 125I rhUG) and significantly decreased by postoperative day 8. The crypt cell production rate in the adjacent mucosa and neomucosa (23.8 +/- 4.2 and 21.9 +/- 2.1 cells/crypt/hr) peaked on the postoperative days 4 and 8, respectively. The epithelial cell migration rate was increased significantly in the neomucosa on the day 2 (33 +/- 2 mm/day) and tapered gradually until postoperative day 12 (14 +/- 1 mm/day). A linear correlation was evident between the rate of epithelialization and uptake of 125I rhUG/EGF in the neomucosa (r = 0.93; p less than or equal to 0.05). These findings suggest that epithelial cell migration occurs earlier than cell proliferation during regeneration of intestinal epithelium and is closely associated with changing concentration of 125I rhUG/EGF in the neomucosa. This suggests that endogenous EGF may play an important role in intestinal regeneration.

Animals↗

PubMed1991

Characterization of a newly established human Burkitt's lymphoma cell line, OMA-BL-1.

Using culture techniques, we have been able to grow occult tumor cells from the bone marrow from cancer patients and have developed a new malignant lymphoid cell line, OMA-BL-1, from the bone marrow of a 17-year-old patient with recurrent Burkitt's lymphoma. The tumor cells grew rapidly in vitro in suspension culture, and very aggressively in vivo in athymic nude mice with metastases to the liver and abdominal cavity. The morphological, chromosomal, immunophenotypic and molecular biologic characteristics of fresh uncultured tumor cells from the patient and tumor cells grown in culture and in athymic nude mice were very similar. The cells were positive for Epstein-Barr virus-associated nuclear antigens (EBNA) and chromosome analysis of the cells revealed an atypical chromosomal abnormality of 45,X,-X,i(8q), HSR(18)(q21),t(8;14)(q24;q32). Southern analysis demonstrated that c-myc was rearranged and amplified in these cells. Immunophenotypic analysis of the cells using flow cytometry showed monoclonal B cells expressing a surface IgG-kappa isotype. The tumor cells grown in nude mice had a significant decrease in CD24 expression when compared to cultured tumor cells. Electron microscopy of the fresh and cultured cells revealed Herpes virus, most likely Epstein-Barr virus, particles. This cell line has been maintained in culture for over 18 months. The aggressive growth and metastatic properties of this cell line in athymic nude mice make it a potentially useful experimental model to study the biology of human lymphoma.

Adolescent↗

PubMed1991

Effect of 6-hydroxydopamine on murine hematopoietic stem cells: enhanced cytotoxicity on megakaryocyte colony forming units.

We examined the effect of catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA) on murine committed megakaryocyte progenitor cells, the megakaryocyte-colony forming unit (CFU-Meg). More mature cells of the megakaryocyte series have the capacity for active uptake of catecholamines, and we speculated that the CFU-Meg would also take up 6-OHDA and be selectively killed. CFU-Meg were much more sensitive to the effects of this agent than were granulocyte-macrophage colony forming units (CFU-GM) or spleen-colony forming units. Co-incubation with catalase, which would destroy hydrogen peroxide generated extracellularly by the autoxidation of 6-OHDA, ablated 6-OHDA toxicity towards CFU-GM, but also significantly reduced the effect on CFU-Meg. Mazindol, a selective dopamine uptake inhibitor did not alter 6-OHDA effect on either CFU-Meg or CFU-GM. Finally, CFU-Meg were no more sensitive to incubation with hydrogen peroxide than were CFU-GM. These data suggest that CFU-Meg, unlike their more mature progeny, do not actively concentrate 6-OHDA, and the excess toxicity of this agent towards CFU-Meg is probably due to increased sensitivity to autoxidation products of 6-OHDA, other than hydrogen peroxide, generated extracellularly.

Animals↗

PubMed1991

Epithelial cell proliferation and uptake of radiolabeled urogastrone in the intestinal tissues following abdominal irradiation in the mouse.

We have evaluated the rate of crypt cell production and uptake of radiolabeled recombinant human urogastrone (125I-rhUG) in the intestinal tissues of the mouse at 3, 5, 7, 9, and 12 days following irradiation of the abdomen with 9 Gy. At autopsy, the animals were injected intraperitoneally with 1 microgram/g body weight of the metaphase arrest agent, vincristine sulfate, and 25 muCi of 125I-rhUG (specific activity 1.7 muCi/micrograms) to quantify the rate of crypt cell production and uptake of radiolabeled urogastrone, respectively. The results indicated that the rate of crypt cell production was increased significantly in the irradiated animals compared to the unirradiated animals and showed a peak on the 3rd and 5th postirradiation days in small intestine and colon, respectively. The uptake of 125I-rhUG was increased significantly on the 3rd postirradiation day in the intestinal tissues but showed a bimodal pattern with peaks on the 3rd and 9th postirradiation days. These results suggest that there may be a close association between epithelial cell proliferation and uptake of 125I-rhUG, particularly in the early part of recovery of intestinal mucosa following irradiation. However, these data do not discriminate whether the increased uptake of 125I-rhUG is the cause or the effect of proliferation induced by an irradiation stimulus. Further analysis also revealed that there was no relationship between crypt depth and 125I-rhUG uptake. However, crypt depth was inversely correlated with villus height in the proximal small intestine but not in the ileum. Villus height was correlated inversely with 125I-rhUG uptake in the ileum and jejunum but not the duodenum. The rate of crypt cell production was strongly correlated with crypt depth throughout the intestine and inversely correlated with villus height. This suggests that villus-to-crypt inhibitory feedback may be a primary regulator of cellular proliferation in the crypts and the association of 125I-rhUG uptake with proliferation indirectly reflects this interaction.

Animals↗

PubMed1990

Effect of age on intestinal regeneration in the rabbit.

We compared the rate of regeneration of full thickness serosa patched intestinal defects to determine whether this regenerative process is influenced by age. Twenty-five rabbits aged 3, 9, 15, 36 and 60 months were killed 3 weeks after patching. Epithelialization was slightly but significantly greater in the 3-month-old rabbits but there were no differences in contraction of the patched defect or villus development of the regenerating mucosa. Disaccharidase activity was greatest in the older animals but glucose uptake was similar at all ages. Proliferative activity was similar as well. Thus, intestinal regeneration in full thickness intestinal defects does not appear to be influenced significantly by the age of the animals.

Aging↗

PubMed1990

Levels of detection of tumor cells in human bone marrow with or without prior culture.

With an in vitro culture technique combined with light microscopy, immunocytochemistry and molecular probing, we previously detected occult tumor cells in histologically-normal human bone marrow harvested for autologous transplantation. In this study, we mixed known numbers of malignant lymphoid (Raji and CEM) or breast cancer (MCF-7) cells with normal human bone marrow cells to determine the levels at which tumor cells can be detected before and after culture. Cytocentrifuge preparations were made before culture and after 2 or more weeks of culture and examined by light microscopy. We detected contaminating lymphoma cells at a level of more than 5% before culture, and at a level of 0.01% after culture for 2 or more weeks in 2% human lymphocyte conditioned medium. Before culture, we detected MCF-7 cells at a level of 0.001% using glucose oxidase immunocytochemical staining techniques; these cells were detected at a level of 0.00001% after culture. Since, of necessity, these calibrations rations were performed using cell lines, it is likely that these results overestimate the absolute sensitivity of these methods for detection of tumor cells in patient samples. We found the glucose oxidase immunocytochemical method more specific for detecting occult tumor cells in bone marrow than the immunoperoxidase staining method because of the absence of non-specific staining arising from endogenous peroxidase in bone marrow cells which makes the interpretation of the latter difficult. We conclude that culture techniques can increase the sensitivity of detection of occult tumor cells in human bone marrow about 100-fold.

Bone Marrow↗

PubMed1989

Effect of eflorithine on intestinal regeneration.

Patching intestinal defects with adjacent serosal surfaces results in the growth of new intestinal mucosa. Since polyamine biosynthesis is associated with cellular growth and differentiation, it may be important in this regenerative process. Our aim was to determine the effect of eflorithine (difluoromethylornithine), a specific inhibitor of polyamine synthesis, on intestinal regeneration. Forty-eight New Zealand white rabbits had 2 x 5-cm ileal defects patched with adjacent cecal serosal surface. One half of the animals took 2% eflorithine in drinking water postoperatively. Six animals in each group were killed 7, 14, 21, and 28 days after patching. There was no significant difference in neomucosal growth at any time. Villous height, disaccharidase activity, and crypt cell production were significantly lower in the eflorithine-treated animals. Eflorithine-treated animals had significantly lower ornithine decarboxylase activity and polyamine levels. Despite the inhibitory effect of eflorithine on polyamine synthesis and proliferative activity, epithelialization and contraction of the patched defect were not affected. These findings suggest that polyamine synthesis is important in proliferation and differentiation of cells in the neomucosa but does not influence cell migration in intestinal regeneration.

Animals↗

PubMed1989

Effect of the duration of infusion of urogastrone on intestinal regeneration in rabbits.

Urogastrone (UG) increases the rate of mucosal regeneration on patched intestinal defects. Our aim was to determine the effect of the duration of UG administration on regeneration of serosa patched ileal defects in rabbits. Group I (n = 18) were controls. Group II (n = 15), Group III (n = 10) and Group IV (n = 5) received UG 1.5 micrograms/kg/h subcutaneously for 7 days, 14 days or 21 days respectively. Animals were sacrificed at 7 day intervals up to 21 days after patching. Neomucosal growth was significantly greater in the animals receiving UG and was greatest in Group IV. Group II and III animals had less contraction of the patched defect and greater neomucosal surface area than Group I animals at each interval but had a lesser effect than animals receiving UG continuously. Crypt cell production rate was significantly greater in UG treated animals at 7 and 14 days but fell to control levels at 21 days. Prolonging the duration of UG infusion increased the quantity of neomucosa produced by intestinal regeneration. However, UG stimulation of mucosal cell migration and proliferation occurred transiently within 14 days after patching.

Analysis of Variance↗

PubMed1989

Comparison of the growth and metastasis of four human intestinal tumor cell line xenografts.

The growth and metastasis of four human intestinal tumor cell lines: one duodenal adenocarcinoma (HTB-40) and three adenocarcinomas of the colon (CCL-218, CCL-222 and HT-29) have been compared in vitro and in vivo in nude mice. HTB-40 was the fastest growing cell line in vitro with a doubling time (DT) of 14.8 h. CCL-218 and CCL-222 grew more slowly in vitro with doubling times of 21.6 and 22.8 hours, respectively. All three of these tumors grew more slowly in vivo with doubling times ranging from 39.1 h (CCL-218 in male nude mice) to 65.3 h (CCL-222). The growth of CCL-218 cells was significantly slower in female nude mice DT 51.0 h). HT-29 was the slowest growing in vitro (DT 23.8 h) and in vivo (DT about 100 h). HT-29 also showed the greatest discrepancy between its DT measured in vivo as compared to in vitro, suggesting a greater clonogenic cell loss from HT-29 tumors in vivo. Histologic evaluation of these tumors grown subcutaneously in nude mice showed all to be anaplastic and to produce liver micrometastases. However, more extensive abdominal and liver metastases were observed in the nude mice injected with HT-29 cells, and some of these metastases had morphologic features of moderately well-differentiated epithelium. These results indicate the usefulness of the HT-29 tumor cell line as an experimental model of metastasis from a human colonic adenocarcinoma.

Animals↗

PubMed1989

The effect of the route of delivery of urogastrone on intestinal regeneration.

Urogastrone (UG) administered subcutaneously increases the rate of intestinal regeneration (neomucosal growth) on patched intestinal defects. Our purpose was to determine the optimal route of delivery of UG for intestinal regeneration. In 22 New Zealand white rabbits (2.1 to 3.4 kg) 2 X 5 cm ileal defects were patched with adjacent cecal serosal surface. Group I (n = 6) served as controls. Group II (n = 5), group III (n = 6), and group IV (n = 5) received UG, 1.5 micrograms/kg/hr, intravenously, subcutaneously, and intraluminally via miniosmotic pumps. Neomucosal growth was assessed 7 days after patching. Serum UG levels were detectable in only the intravenous group. Coverage of the patched defect and neomucosal area was significantly greater and contraction of the defect less in the groups receiving UG (p less than 0.05). Neomucosal area was highest in the intravenous group (286 +/- 16 mm2), intermediate in groups III and IV (236 +/- 19 and 215 +/- 20 mm2), and lowest in the control group (152 +/- 17 mm2; p less than 0.05). Sucrase and maltase activities were significantly higher in the intravenous group. Crypt cell production rate and ornithine decarboxylase activity were greater in the UG-treated animals. UG stimulated intestinal regeneration by all routes of delivery. The intravenous route had the greatest effect and was associated with the highest serum levels of UG. These findings have implications for the mechanism of the trophic effect of UG on the intestinal epithelium.

Amine Oxidase (Copper-Containing)↗