Characteristics of peripheral blood monocytes and bone marrow macrophages from rats treated with mitomycin C, 5-fluorouracil or phenylhydrazine

The Suppression of Wound Healing Response with Sirolimus and Sunitinib Following Experimental Trabeculectomy in a Rabbit Model

PURPOSE

To investigate the effects of sirolimus and sunitinib on wound healing in experimental glaucoma filtering surgery (GFS).

MATERIAL AND METHODS

Thirty-five male New Zealand pigmented rabbits were randomly assigned to five groups, each including seven rabbits: The rabbits in the control group were not operated on and did not receive any treatment. The rabbits in the sham group underwent trabeculectomy and had one drop of saline instilled four times a day for 14 days. The rabbits in the mitomycin-C (MMC) group underwent trabeculectomy, and a sponge soaked in 0.4 mg/mL MMC was applied intraoperatively to the scleral surgical site for three minutes. The rabbits in the sirolimus group underwent trabeculectomy and 30 ng/mL sirolimus-soaked sponge was applied intraoperatively to the scleral surgical site for three minutes. Sunitinib 0.5 mg/mL four drops in a day were applied in the sunitinib group for 14 days after surgery. On day 14 of the experiment, eyes were enucleated and histologically and immunohistochemically analyzed. Statistical analyses of the study were performed with Kruskal-Wallis variance analysis and Mann-Whitney U test.

RESULTS

The mean fibroblast and MNC numbers and the mean immunostaining intensities of transforming growth factor-β (TGF-β), fibroblast growth factor-β (FGF-β) and platelet derived growth factor (PDGF) in the MMC, sirolimus and sunitinib groups were statistically significantly lower than those of the sham group (p < 0.01). The mean fibroblast and MNC numbers and the mean immunostaining intensities of TGF-β, FGF-β and PDGF in the MMC, sirolimus and sunitinib groups were similar (p > 0.05).

CONCLUSIONS

Our study suggests that the applications of sirolimus and sunitinib effectively suppress the subconjunctival scarring after experimental GFS.

Impact of trastuzumab on wound healing in experimental glaucoma surgery

BACKGROUND

To investigate the effects of subconjunctivally administered trastuzumab on wound healing in experimental glaucoma filtration surgery.

DESIGN

Comparative, experimental study.

SAMPLES

Twenty eight eyes.

METHODS

Twenty-eight male New Zealand white rabbits were randomly assigned to four groups, each including seven rabbits: The rabbits in the control group were not operated on and did not receive any treatment. The rabbits in the sham group underwent trabeculectomy and had one drop of saline instilled four times a day for 14 days. The rabbits in the mitomycin-C group underwent trabeculectomy, and a sponge soaked in 0.4 mg/mL mitomycin-C was applied intraoperatively to the scleral surgical site for 3 min. The rabbits in the trastuzumab group underwent trabeculectomy and were injected subconjunctivally once with 1.2 mg/0.1 mL of the drug. On day 14 of the experiment, the operated and control eyes were enucleated and immunohistochemically analyzed.

MAIN OUTCOME MEASURES

Mean values of fibroblast, mononuclear cell and immunostaining intensities of the transforming growth factor-β, fibroblast growth factor-β, and platelet derived growth factor.

RESULTS

The mean cell numbers and immunostaining intensities in the sham group were higher than those of the control group (P < 0.01). The mean cell numbers and immunostaining intensities in the mitomycin-C group and trastuzumab group were statistically significantly lower than those of the sham group (P < 0.01) while mean cell numbers and immunostaining intensities in the mitomycin-C group and trastuzumab group were similar (P > 0.05).

CONCLUSION

Subconjunctival trastuzumab injection effectively suppressed subconjunctival scarring after experimental glaucoma filtration surgery.

Modulation of postoperative scarring with tacrolimus and octreotide in experimental glaucoma filtration surgery

PURPOSE

The purposes of this study were to investigate the effects of topically administrated Tacrolimus and Octreotide on modulation of postoperative scarring in experimental glaucoma filtration surgery and to compare the antifibrotic properties of these agents with mitomycin-C (MMC).

MATERIAL AND METHODS

A total of 28 New Zealand rabbits weighing 2.5-3 kg were randomly divided into a surgical control (SC) group and three experimental groups. Standard filtration surgeries were performed on the right eyes of all the rabbits. The rabbits in the SC group received only vehicle after the surgeries, whereas the rabbits in the three experimental groups were treated either with 0.4 mg/mL MMC during the surgery (MMC group) or with 0.3 mg/mL Tacrolimus drop four times a day (TT group) or with 10 µg/mL Octreotide drop three times a day (OT group) for 14 days. The animals were killed on day 14, eyes were enucleated and histologically and immunohistochemically analyzed.

RESULTS

In SC group mean fibroblast, mononuclear cell number and fibroblast growth factor-β (FGF-β), transforming growth factor-β (TGF-β) immunostaining intensity was higher than all treatment groups. In OT group mean fibroblast number was lesser than MMC (p < 0.01) and TT (p < 0.05) group. In TT group mean fibroblast number was lesser than MMC group (p < 0.05). Mean mononuclear cell number was similar between MMC, OT and TT groups (p > 0.05). In MMC, OT and TT groups mean TGF-β and FGF-β immunostaining intensity was similar (p > 0.05).

CONCLUSIONS

Topically administration of Tacrolimus and Octreotide effectively reduced the subconjuntival scarring response 2 weeks after experimental glaucoma filtration surgery.

Antitumor activity of Pulsatilla chinensis (Bunge) Regel saponins in human liver tumor 7402 cells in vitro and in vivo

Pulsatilla chinensis (Bunge) Regel is a Chinese medicinal herb for "blood-cooling" and detoxification. Now it is used for the treatment of malignant tumor, but the antitumor mechanisms and toxic side effects of P. chinensis are unclear. The present study was undertaken to investigate if P. chinensis saponins (PRS) possesses anticancer effects and toxic side effects in human liver tumor 7402 cells in vitro and vivo. 7402 cells were treated with different concentrations of PRS for 24h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry. The in vivo effect of PRS on 7402 tumor cells transplanted in athymic nude mice was investigated. 15 saponins were isolated and identified from PRS. PRS inhibited the proliferation of human liver tumor 7402 cells in vitro by apoptosis. 19 days after administration of PRS (100, 200mg/kg), the weight of tumor mass was markly decreased in nude mice. The anti-tumor effect of PRS in vivo was associated with a significant increase in the 7402 apoptosis rate. Although PRS inhibited the weight of mice, it showed almost no effect on leukocyte number, liver and spleen weight index. Light microscopic histopathological examination showed that PRS had no specific lesion in organ. These results suggested that P. chinensis saponins exert potential anticancer activity in treating tumors in nude mice and no toxic side effects.

Engraftment of syngeneic and allogeneic endothelial cells, hepatocytes and cholangiocytes into partially hepatectomized rats previously treated with mitomycin C

BACKGROUND

Pretreatment with retrorsine crosslinks host hepatocyte DNA and prevents proliferation after partial hepatectomy (PH), allowing selective expansion of transplanted progenitors. Shortcomings are length of protocol and carcinogenicity of retrorsine.

METHODS

This report describes a rapid liver repopulation protocol using mitomycin C (MMC) to block proliferation of rat hepatocytes in response to PH. One week post-MMC treatment, dipeptidyl peptidase IV negative host rats were given a PH followed by injection of late gestation, newborn, or adult total liver isolates from dipeptidyl peptidase IV positive rats. For allogeneic transplantation, host rats received injections of anti-CD3 antibody before and after PH.

RESULTS

Host liver staining 2 to 9 weeks posttransplantation revealed well-defined donor hepatocyte colonies with strong canalicular dipeptidyl peptidase IV activity. At the same cell dose, fetal and newborn isolates produced more colonies than adult liver isolates. Hepatocyte colonies also coexpressed marker proteins characteristic of adult hepatocytes and showed polarized localization of plasma membrane proteins. Host livers contained large clusters of sinusoids lined by dipeptidyl peptidase IV positive endothelial cells coexpressing the endothelial cell marker, RECA-1, but lacked the canalicular marker leucine aminopeptidase. Colonies containing donor hepatocytes, endothelial cells, and bile ducts were also observed. Similar levels of engraftment and expansion were achieved with allogeneic liver cell isolates by using anti-CD3 antibody treatment.

CONCLUSIONS

The MMC transplantation model provides a rapid method for engraftment and expansion of hepatocytes, endothelial cells, and cholangiocytes and should be applicable to investigations centering on the role of endothelial cells in liver regeneration and the identification and characterization of putative endothelial, hepatocyte, and cholangiocyte progenitors.

Importance of starting age for myelotoxicity study in dietary restricted rats

The aim of this study was to prove our hypothesis that adult rats with lowering of body weight gain, rats at 12 weeks of age as an example, are suitable for evaluation of myelotoxicity. Age-related differences between young rats (6-week-old study) and adult rats (12-week-old study) were analyzed in hematological examination values. The data of the young rats were reprinted from our previous report (Miyata et al., 2009) since our hypothesis was verified by comparison with that previous report. Several experimental groups were defined for the 12-week-old study as well as for the 6-week-old study; these included 5-fluorouracil (5-FU) treated groups receiving 12, 15 and 18 mg/kg/day (FU12, FU15 and FU18), pair-feeding groups (R12, R15 and R18 receiving the same amount of food as in the FU12, FU15 and FU18 groups, respectively) and a nontreated control group. Numerous hematologic and bone marrow parameters in the 5-FU treated groups were comparable to those in the corresponding pair-feeding groups in both age studies. Generally, the influences of undernutrition were more apparent in the young rats than in the adult rats. Histopathological examinations showed a decrease in hematopoiesis in the bone marrow in the 5-FU treated and pair-feeding groups. No apparent differences were observed in the decreased hematopoiesis between the 5-FU treated and pair-feeding groups in the 6-week-old study, but a difference between these groups was noted in the 12-week-old study; decreased hematopoiesis was more frequently noted in the 5-FU treated groups. These facts suggest that adult rats are more suitable than young rats for evaluation of 5-FU-induced myelotoxicity.

Evaluation of myelotoxicity in dietary restricted rats

The purpose of this study was to clarify the effect of decreased food consumption on evaluation of myelotoxicity in routine general toxicity studies. Male rats were divided into the following 7 groups: 12, 15, and 18 mg/kg 5-fluorouracil (5-FU) treatment groups (FU12, FU15 and FU18); dietary restriction groups (R12, R15 and R18 receiving the same amount of food as the rats in the FU12, FU15 and FU18 groups, respectively); and a nontreated control group (NT). We compared the changes in body weight, hematology and the results of cytological analyses of bone marrow and histopathology among the groups after administration and recovery periods of 14 and 7 days, respectively. At the end of the administration period, the FU15 and FU18 groups showed decreases in many hematologic and bone marrow parameters that were all similar to those in the corresponding dietary restriction groups (R15 and R18). A granulocyte abnormality (polyploidy: frequency of 1% or less) was also observed in all 5-FU treated groups. At the end of the recovery period, increases in the reticulocyte and platelet counts and extramedullary hematopoiesis of the spleen were observed in the 5-FU treated groups. These results indicate that the results of general toxicity studies in rats should be evaluated in consideration of dietary restriction effects when food consumption is decreased at about 30-40% or more. Careful morphological observation of hemocytes would be helpful in distinguishing the effect of a drug from that of dietary restriction in relation to hematological and bone marrow parameters. Performance of a recovery test to determine the reactive response of hematopoiesis is also recommended.

The haemotoxicity of mitomycin in a repeat dose study in the female CD-1 mouse

Mitomycin (MMC), like many antineoplastic drugs, induces a predictable, dose-related, bone marrow depression in man and laboratory animals; this change is generally reversible. However, there is evidence that MMC may also cause a late-stage or residual bone marrow injury. The present study in female CD-1 mice investigated the haematological and bone marrow changes induced by MMC in a repeat dose study lasting 50 days. Control and MMC-treated mice were dosed intraperitoneally on eight occasions over 18 days with vehicle, or MMC at 2.5 mg/kg, autopsied (n = 6-12) at 1, 7, 14, 28, 42 and 50 days after the final dose and haematological changes investigated. Femoral nucleated bone marrow cell counts and levels of apoptosis were also evaluated and clonogenic assays carried out; serum levels of FLT3 ligand (FL) were assessed. At day 1 post-dosing, MMC induced significant reductions in RBC, Hb and haematocrit (HCT) values, and there were decreases in reticulocyte, platelet, and femoral nucleated cell counts (FNCC); neutrophil, lymphocyte and monocyte values were also significantly reduced. On days 7 and 14 post-dosing, all haematological parameters showed evidence of a return towards normal values, but at these times, and at day 28, values for RBC and FNCC remained significantly reduced in comparison with controls. At days 42 and 50 post-dosing, many haematological parameters in MMC-treated mice had returned to control levels; however, there remained evidence of late-stage effects on RBC, Hb and HCT values, and FNCC also continued to be significantly decreased. Results for granulocyte-macrophage colony-forming units and erythroid colonies showed a profound decrease immediately post-dosing, but a return to normal values was evident at day 50. Serum FL concentrations demonstrated very significant increases in the immediate post-dosing period, but a return to normal was seen at day 50 post-dosing; a relatively similar pattern was seen in the number of apoptotic femoral marrow nucleated cells. The histopathological examination of kidney tissues from MMC animals at day 42 and 50 post-dosing showed evidence of hydronephrosis with cortical glomerular/tubular atrophy and degeneration. It is therefore concluded that MMC administered on eight occasions over 18 days to female CD-1 mice at 2.5 mg/kg induced profound changes in haematological and bone marrow parameters in the immediate post-dosing period with a return to normal levels at day 50 post-dosing; however, there was evidence of mild but significant late-stage/residual effects on RBC and FNCC, and on cells of the erythroid lineage in the bone marrow.

Evaluation of antitumor and toxic side effects of mitomycin C–estradiol conjugates

The antitumor and toxic side effects of mitomycin C-estradiol conjugates (EB-glu-MMC and E-glu-MMC) were evaluated in detail for solutions in propylene glycol and suspensions in 10% (v/v) propylene glycol. Tumor growth, body weight and number of leukocytes were examined after i.p. administration to sarcoma 180 solid tumor-bearing mice. Body weight and number of leukocytes were also examined in normal mice after i.p. administration of the solution. In solution dosage forms, the two conjugates had almost the same suppressive effect on tumor growth at 30 mg MMC eq./kg as MMC at 5 mg/kg, did not lower body weight significantly, but reduced the number of leukocytes at 30 mg MMC eq./kg. MMC, lethally toxic at 10 mg, significantly lowered the body weight and leukocyte number. In the suspension dosage forms, these conjugates had a greater suppressive effect on tumor growth at 50 mg MMC eq./kg than MMC at 5 mg/kg, and reduced the body weight and leukocyte number, with E-glu-MMC more toxic than EB-glu-MMC. The presence of the tumor itself influenced the body weight and leukocyte number. However, toxic side effects could be evaluated from the body weight and leukocyte number to almost the same extent between tumor-bearing and normal mice.

Reduced progression of atherosclerosis in apolipoprotein E-deficient mice with phenylhydrazine-induced anemia

Epidemiological and experimental studies suggest that circulating erythrocytes play a role in the incidence of coronary heart disease. We investigated the influence of phenylhydrazine (PHZ)-induced anemia on the formation of atherosclerotic lesions in apo E-deficient mice on regular chow and on a high-fat, high-cholesterol diet during 10 weeks. The repeated doses of PHZ caused sustained anemia throughout the study, changes in the physical characteristics of erythrocytes and increased reticulocyte count. The lesions of the anemic animals were smaller than in the controls and this was even more evident in mice fed with the atherogenic diet. A positive correlation was found between circulating red blood cells at the end of the experiment and the area of aortic lesion. There was also a negative association between the lesion and the reticulocyte count. This reduced progression of atherosclerotic lesions is independent of nutritional status or the lipoprotein cholesterol distribution. The results suggest that mechanisms related to the number of circulating red blood cells may have a significant influence on the development of atherosclerosis.

Effect of amiodarone on release of cytokines from mouse alveolar macrophages pretreated with eicosapentaenoic acid

I studied the effect of amiodarone, a cationic amphiphilic drug, on the cytokine release and protein kinase C (PKC) activity of mouse alveolar macrophages. In addition, I examined the relationship between amiodarone and eicosapentaenoic acid (EPA) with respect to the cytokine release. The decrease in cell number caused by amiodarone was depressed by pretreatment of the macrophages with EPA for 2 days and co-treatment for 1 day. These changes reflected the potency of EPA to protect against the cell injury elicited by amiodarone. As regards to the cytokine release, amiodarone caused an increase in interleukin (IL)-1 alpha, IL-1 beta and tumor necrosis factor (TNF) alpha release from macrophages. As EPA suppressed this increase in cytokine levels, I considered that the protective effect of EPA may be extended to the acute release of cytokines. PKC activity was increased by amiodarone, and this increase was depressed by EPA. These changes were well-related to the results on cytokine levels in this study, indicating that amiodarone firstly activated PKC, leading to the stimulation of release of cytokines and that pretreatment with EPA prevented these effects. I conclude that mouse alveolar macrophages treated with amiodarone show activated release of cytokines and that EPA depresses these increases, thereby demonstrating EPA's anti-inflammatory effect and protective action against injury of alveolar macrophages.