Heparin-binding epidermal growth factor (HB-EGF) may improve embryonic development and implantation by increasing vitronectin receptor (integrin alphanubeta3) expression in peri-implantation mouse embryos

PURPOSE

This study investigated the effects of HB-EGF on expression of integrin alphanubeta3 and implantation of embryos.

METHODS

Two-cell embryos were recovered and cultured with or without 10 ng/mL HB-EGF for 96h. Expression of integrin alphanubeta3 in cultured embryos was examined by real time-RT-PCR and immunofluorescence analysis; embryos were cultured with or without HB-EGF, then transferred into the uteri of pseudo-pregnant female mice in order to analyze their implantation rate.

RESULTS

HB-EGF improved embryonic hatching and outgrowth during extended culture, and up-regulated expression of integrin alphanubeta3 in both the preimplantation embryo and outgrowing blastocyst. Also, integrin alphanubeta3 subunits were localized at the pericellular borders and cell-cell contact areas. The number of successful implantation sites of transferred HB-EGF-treated embryos in the uterus was increased when compared to number of implantation sites with non-treated controls.

CONCLUSIONS

HB-EGF may improve implantation by accelerating expression of integrin alphanubeta3 in peri-implantation mouse embryos.

Heparin-binding epidermal growth factor-like growth factor reduces intestinal apoptosis in neonatal rats with necrotizing enterocolitis

PURPOSE

We have previously demonstrated that enterally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF) decreases the incidence and severity of necrotizing enterocolitis (NEC) in a neonatal rat model. Because apoptosis contributes to gut barrier failure in this model, the aim of this study was to investigate the effect of HB-EGF on apoptosis during the development of NEC.

METHODS

NEC was induced in neonatal rats by exposure to hypoxia, hypothermia, hypertonic formula feeding (HHHTF) plus enteral administration of lipopolysaccharide (LPS). Fifty-one neonatal rats were randomly divided into the following groups: (1) breast-fed (BF), (2) HHHTF + LPS, and (3) HHHTF + LPS with HB-EGF (600 microg/kg) added to the formula. NEC was evaluated using a standard histological scoring system. Apoptotic cells in intestinal tissues were detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) and by active caspase 3 immunohistochemical staining.

RESULTS

The incidence of NEC in the HHHTF + LPS group was higher than that in the BF group (65% vs 0%, P < .05). With administration of HB-EGF, the incidence of NEC significantly decreased to 23.8% (P < .05). The median TUNEL and active caspase 3 scores in the HHHTF + LPS group were higher than those in the BF group (1.9 vs 0.9 and 1.75 vs 0.6, respectively, P < .05). The median TUNEL and active caspase 3 scores were significantly decreased in the HHHTF + LPS + HB-EGF group compared with the HHHTF + LPS group (1.24 vs 1.9 and 1.0 vs 1.75, respectively, P < .05).

CONCLUSION

HB-EGF reduces the incidence of NEC in a neonatal rat model in part by decreasing apoptosis. These results support the use of HB-EGF-based clinical regimens for the treatment of NEC.

[Recombinant human epithelial growth factor accelerates healing of cervical erosion]

OBJECTIVE

To observe the effect of recombinant human epithelial growth factor (rhEGF) in promoting the healing of cervical erosion.

METHODS

Forty-eight patients with cervical erosion were treated with rhEGF and 30 with 500 kHz high-frequency electromagnetic wave, and the effects of the therapies were compared in terms of healing of the cervical wound, healing time, volume of vaginal discharge and bleeding and the lasting time.

RESULTS

In comparison with radiofrequency therapy, the healing of the lesion took significantly shorter time with rhEGF therapy, which also resulted in less vaginal discharge that lasted for shorter time without causing vaginal bleeding.

CONCLUSION

rhEGF can obviously accelerate the healing of cervical erosion.

Effects of interleukin-11 and epidermal growth factor on residual small intestine after experimental massive small bowel resection

Interleukin 11 (IL-11) is a multifunctional cytokine derived from bone marrow, which has a trophic effect on small bowel epithelium. This study compares the effects of IL-11 with epidermal growth factor (EGF), a growth factor known to enhance small bowel adaptation. Forty Sprague-Dawley rats (90-100g) underwent an 85% mid-small bowel resection with primary anastomosis on day 0. Rats were divided into four treatment groups: controls (group I) received bovine serum albumin (BSA), group II received IL-11, 125 microg/kg subcutaneously (SC) twice daily, group III received EGF, 0,10 microg/g SC bid, and group IV received EGF and IL-11 in the above doses. Half of the animals (five per group) were killed on day 4 of therapy, and the rest on day 8. Animals were evaluated for weight, mucosal length, and bowel wall muscle thickness on days 4 and 8, and expression of proliferating cell nuclear antigen (PCNA) in intestinal crypt and smooth muscle cells on day 8. Body weight was similar at day 4 and 8. Mucosal thickness in groups 11 (IL-11) and IV (IL-11 and EGF) was significantly increased at day 4 and 8 compared with controls (group I) and EGF (group III, P<.001). Muscle thickness was significantly increased in the EGF and combined group IV compared with the BSA controls and IL-11 groups (P < .001). Thirty-two percent of the mucosal crypt cells in group I stained positive for PCNA, whereas 51%, 53%, and 60% stained positive in groups II (IL-11), III (EGF), and IV (IL-11 and EGF), respectively. In groups I and II, 2% and 1.7% of the myocytes stained positive for PCNA, whereas 11.2% and 5.2% in group III and IV. These data suggest that IL-11 has a trophic effect on small intestinal enterocytes, causing cell proliferation and increased mucosal thickness. EGF has a more generalized effect causing proliferation of both enterocytes and myocytes. IL-11, with or without EGF may be a useful adjunct in treatment of short bowel syndrome.

Influence of EGF/bFGF treatment on proliferation, early neurogenesis and infarct volume after transient focal ischemia

The persistence of neurogenesis in the adult mammalian forebrain suggests that endogenous precursors may be a potential source for neuronal replacement after injury or neurodegeneration. On the other hand basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) can facilitate neural precursor proliferation in the adult rodent subventricular zone (SVZ) and dentate gyrus. As the application of EGF and bFGF was found to boost neurogenesis after global ischemia, in this study we investigated whether a combined intracerebroventricular (i.c.v.) EGF/bFGF treatment over a period of 2 weeks affects the proliferation of newly generated cells in the endothelin-1 model of transient focal ischemia in adult male Sprague-Dawley rats as well. As assessed by toluidine blue staining, EGF/bFGF substantially increased the infarct volume in ischemic animals. Chronic 5'-bromodeoxyuridine (BrdU) i.c.v. application revealed an EGF/bFGF-induced increase in cell proliferation in the lateral ventricle 14 days after surgery. Proliferation in the striatum increased after ischemia, whereas in the dentate gyrus and in the dorsal 3rd ventricle the number of cells decreased. Analysis of the neuronal fate of these cells by co-staining with a doublecortin (DCX) antibody showed that the growth factors concomitantly nearly doubled early neurogenesis in the ipsilateral striatum in ischemic animals but diminished it in the dentate gyrus. Because of the increased infarct volume and unclear long-term outcome further modifications of a chronic treatment schedule are needed before final conclusions concerning the perspectives of such an approach can be made.

Mechanisms of disease: Radiosensitization by epidermal growth factor receptor inhibitors

The epidermal growth factor receptor (EGFR) inhibitors are among the most intensely studied new molecular therapeutic agents. Although response rates have been somewhat disappointing when EGFR inhibitors are used as single-agent therapy for advanced disease, these inhibitors may be more effective as chemo- and radiosensitizers. The first phase III randomized trial evaluating EGFR inhibitors as radiosensitizers in patients with locally advanced head and neck cancer was strongly positive, indicating significant potential of this class of agents to improve outcome with radiotherapy. However, optimal implementation of EGFR inhibitors as radiosensitizers depends, in part, on a better understanding of the mechanisms of radiosensitization. Preclinical studies provide important observations with regard to potential mechanisms. The phenotypic cellular changes associated with EGFR inhibition are impressively consistent between different model systems, with almost all studies showing that EGFR inhibitors affect proliferation, angiogenesis, and cell survival. Whether EGFR inhibitors influence response to radiation directly, or whether the improved response is a result of additive effects of the two modalities, remains unclear. However, cell-cycle arrest, endothelial cell sensitivity, and apoptotic potential are all important factors in radiation response of epithelial tumors. Furthermore, less-studied effects of EGFR inhibitors on DNA repair suggest that modulation of DNA damage response to cytotoxic injury might result in radio- or chemosensitization. This review will explore potential mechanisms of radiosensitization by EGFR inhibitors.

Epidermal growth factor reduces hepatic sequelae in experimental necrotizing enterocolitis

BACKGROUND AND AIM

Neonatal necrotizing enterocolitis (NEC) is the most common gastrointestinal disease of premature infants. We recently demonstrated that the gut/liver axis plays an important role in the pathophysiology of NEC through the release of inflammatory mediators into the intestinal lumen. We have also shown that supplementation of formula with epidermal growth factor (EGF) dramatically decreases ileal pathology associated with experimental NEC. In this study, we examined the effects of EGF on the liver portion of the gut/liver axis in the neonatal rat model of NEC.

METHODS

Newborn rats were divided into three experimental groups, NEC, hand-fed with growth-factor free formula; NEC + EGF, hand-fed with formula supplemented with 500 ng/ml rat EGF; or DF, dam fed. All animals were exposed to asphyxia and cold stress twice daily for 4 days to develop NEC.

RESULTS

EGF receptor expression was significantly (p <or= 0.01) decreased in the NEC+EGF group compared to the NEC group. EGF supplementation significantly decreased Kupffer cell numbers (p <or= 0.01) as well as hepatic tumor necrosis factor (TNF)-alpha and interleukin-18 production (p <or= 0.05). Further, TNF-alpha in the intestinal luminal contents of the NEC+EGF group were normalized to levels observed in DF controls compared to the NEC group (p <or= 0.05). Activated nuclear factor-kappaB was also substantially decreased in the NEC+EGF group versus the NEC group.

CONCLUSION

The results of this study indicate that EGF normalizes cytokine overproduction in the liver of neonatal rats with NEC, which contributes to diminished intestinal damage during the development of experimental NEC. These data suggest that supplementation of formula with EGF can have beneficial effects on the gut/liver axis during NEC pathogenesis.

Enhancing dermal matrix regeneration and biomechanical properties of 2nd degree-burn wounds by EGF-impregnated collagen sponge dressing

To better define the relationship between dermal regeneration and wound contraction and scar formation, the effects of epidermal growth factor (EGF) loaded in collagen sponge matrix on the fibroblast cell proliferation rate and the dermal mechanical strength were investigated. Collagen sponges with acid-soluble fraction of pig skin were prepared and incorporated with EGF at 0, 4, and 8 microg/1.7 cm2. Dermal fibroblasts were cultured to 80% confluence using DMEM, treated with the samples submerged, and the cell viability was estimated using MTT assay. A deep, 2nd degree- burn of diameter 1cm was prepared on the rabbit ear and the tested dressings were applied twice during the 15-day, post burn period. The processes of re-epithelialization and dermal regeneration were investigated until the complete wound closure day and histological analysis was performed with H-E staining. EGF increased the fibroblast cell proliferation rate. The histology showed well developed, weave-like collagen bundles and fibroblasts in EGF-treated wounds while open wounds showed irregular collagen bundles and impaired fibroblast growth. The breaking strength (944.1 +/- 35.6 vs. 411.5 +/- 57.0 Fmax, gmm(-2)) and skin resilience (11.3 +/- 1.4 vs. 6.5 +/- 0.6 mJ/mm2) were significantly increased with EGF-treated wounds as compared with open wounds, suggesting that EGF enhanced the dermal matrix formation and improved the wound mechanical strength. In conclusion, EGF-improved dermal matrix formation is related with a lower wound contraction rate. The impaired dermal regeneration observed in the open wounds could contribute to the formation of wound contraction and scar tissue development. An extraneous supply of EGF in the collagen dressing on deep, 2nd degree-burns enhanced the dermal matrix formation.

E1-INT (Transition Therapeutics/Novo Nordisk)

Transition Therapeutics (through its acquisition of Waratah Pharmaceuticals), in collaboration with Novo Nordisk, is developing E1-INT, an injectable islet neogenesis therapy comprising an epidermal growth factor analog and a gastrin analog, for the treatment of insulin-dependent (type 1) and non-insulin-dependent (type 2) diabetes. The compound is currently undergoing phase II clinical trials.

Rational design of an EGF-IL18 fusion protein: implication for developing tumor therapeutics

Interleukin-18 (IL-18) is a proinflammatory cytokine. This protein has a role in regulating immune responses and exhibits significant anti-tumor activities. Epidermal growth factor (EGF) is an important growth factor that plays a central role in the regulation of cell cycle and differentiation. It was proposed that a targeted delivery of IL-18 by generation of IL-18-EGF fusion protein might decrease adverse effects and result in enhancing cytotoxic and antitumor activities. In the present study, a fusion protein, consisting of EGFR binding domain fused to human IL-18 mature peptide via a linker peptide of (Gly(4)Ser) 3, was constructed and expressed in the insect cell line Sf9 using Bac-to-Bac baculovirus expression system. We showed that the purified recombinant fusion protein induced similar levels of IFN-gamma to that of native IL-18 protein in human PBMC in the presence of ConA. Furthermore, EGF receptor competitive test in human epithelial cancer A431 cell line showed that EGF-IL18 fusion protein can specifically bind with EGFR by competing with native EGF protein. These suggest that this rationally designed protein can be further developed as novel tumor therapeutics.

[Radiobiological effect of 131I radiolabeled recombinant human epidermal growth factor on nude mice with human breast cancer]

The radiobiological effect of 131I radiolabeled recombinant human epidermal growth factor (131I-rhEGF) on nude mice with human breast cancer was assessed in this study. The tissue mainly uptaking 131I-rhEGF was found by tissue distribution assay in mice. The radiation breakdown of the tissue greatly collecting 131I-rhEGF was examined by biochemical test and biopsy in nude mice with human breast cancer. The tissue distribution assay of 131I-rhEGF in mice showed that 131I-rhEGF greatly accumulated in kidney, liver, spleen and blood. The biochemical test and biopsy revealed that 131I -rhEGF injected twice (dosing once is analogous to 14.58 GBq in a person with 50 kg, once every 14 days) had an effective killing effect on tumor but had no effect of radiation breakdown on kidney, liver,spleen and blood-cell forming tissue in mice with human breast cancer. Therefore, 131I-rhEGF is a drug unharmful to normal tissues in the course of the receptor-mediated target radiotherapy for breast cancer.

Heparin-binding EGF-like growth factor (HB-EGF) and necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a common and devastating gastrointestinal disease that occurs predominantly in premature infants. Despite various advances in management, the mortality of this disease remains high. During the last decade, studies from our laboratory have shown that heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, can protect intestinal epithelial cells (IEC) from various forms of injury in vitro. Furthermore, we have used both an intestinal I/R injury model in adult rats, and a neonatal rat pup model of NEC, to show that HB-EGF can protect the intestines from injury. On administration of HB-EGF in the neonatal rat model, the incidence of NEC is reduced from 65% to 27.3% (P < 0.05), and the histological injury score is decreased from 2 to 1.1 (P < 0.05). In addition, the survival rate is increased from 25% to 63.6% and the survival time extended from 59 hours to 73 hours (P < 0.05). In addition, using human specimens from newborns undergoing bowel resection for NEC, we found that the expression of endogenous HB-EGF mRNA in normal areas of the intestine at the resection margins was higher than that of the intestine afflicted with acute NEC. Endogenous HB-EGF may be involved in epithelial cell repair, proliferation, and regeneration during recovery from injury. Exogenous administration of HB-EGF potentiates recovery from intestinal injury in vitro and in vivo. Taken together, these results support a potential therapeutic role for HB-EGF in the treatment of NEC in the future.

A pilot study of the use of epidermal growth factor in pediatric short bowel syndrome

BACKGROUND

This study examined the effects of enterally administered epidermal growth factor (EGF) on nutrient absorption and tolerance of enteral feeds in pediatric patients with short bowel syndrome (SBS).

METHODS

Patients identified with severe SBS (<25% bowel length predicted for age) were prospectively enrolled in treatment using human recombinant EGF (1-53); 100 microg/kg per day given mixed with enteral feeds and patients were treated for 6 weeks. End points followed were patient weight, tolerance of enteral feeds, nutrient absorption, and intestinal permeability as determined using carbohydrate probes and hematologic values for liver function parameters.

RESULTS

Five patients were treated with EGF; all showed a significant improvement in carbohydrate absorption (3-0 methylglucose): absorption 24.7% +/- 9.7% pretreatment vs 34.1% +/- 13.8% posttreatment and improved tolerance of enteral feeds (enteral energy as % of total energy, 25% +/- 28% pretreatment vs 36% +/- 24% posttreatment; mean +/- SD; P < .05 by Wilcoxon's signed rank test). Epidermal growth factor treatment was not associated with significant changes in intestinal permeability, the rate of weight gain, or liver function tests. During the treatment phase, no patients developed episodes of sepsis; however, within 2 weeks of discontinuation of EGF treatment, 3 patients developed septic episodes. No adverse effects of EGF administration were noted.

CONCLUSIONS

These results suggest that enteral treatment with EGF in pediatric SBS improves nutrient absorption, increases tolerance with enteral feeds, and may improve the infection rate. Further studies exploring treatment strategies including the timing and duration of EGF administration are indicated.

Adenovirus-Mediated Gene Transfer of Heparin-Binding Epidermal Growth Factor-Like Growth Factor Enhances Neurogenesis and Angiogenesis After Focal Cerebral Ischemia in Rats

Background and Purpose— Recent studies have demonstrated that neurotrophic factors promote neurogenesis after cerebral ischemia. However, it remains unknown whether administration of genes encoding those factors could promote neural regeneration in the striatum and functional recovery. Here, we examined the efficacy of intraventricular injection of a recombinant adenovirus-expressing heparin-binding epidermal growth factor-like growth factor (HB-EGF) on neurogenesis, angiogenesis, and functional outcome after focal cerebral ischemia.

Methods— Transient focal ischemia was induced by middle cerebral artery occlusion (MCAO) for 80 minutes with a nylon filament in Wistar rats. Three days after MCAO, either adenovirus-expressing HB-EGF (Ad-HB-EGF) or Ad-LacZ, the control vector, was injected into the lateral ventricle on the ischemic side. Bromodeoxyuridine (BrdU) was injected intraperitoneally twice daily on the sixth and seventh days. On the eighth or 28th day after MCAO, we evaluated infarct volume, neurogenesis, and angiogenesis histologically. Neurological outcome was serially evaluated by the rotarod test after MCAO.

Results— There was no significant difference in infarct volume between the 2 groups. Treatment with Ad-HB-EGF significantly increased the number of BrdU-positive cells in the subventricular zone on the 8th day. In addition, on the 28th day, BrdU-positive cells differentiated into mature neurons in the striatum on the ischemic side but seldom the cells given Ad-LacZ. Enhancement of angiogenesis at the peri-infarct striatum was also observed on the eighth day in Ad-HB-EGF–treated rats. Treatment with Ad-HB-EGF significantly enhanced functional recovery after MCAO.

Conclusions— Our data suggest that gene therapy using Ad-HB-EGF contributes to functional recovery after ischemic stroke by promoting neurogenesis and angiogenesis.

Interstitial diphtheria toxin-epidermal growth factor fusion protein therapy produces regressions of subcutaneous human glioblastoma multiforme tumors in athymic nude mice

PURPOSE

The novel fusion protein, DAB389EGF, composed of the catalytic and translocation domains of diphtheria toxin (DAB389) fused with a His-Ala linker to human epidermal growth factor (EGF) was tested for antiglioma efficacy in an in vivo model of human glioma.

EXPERIMENTAL DESIGN

Female athymic nude mice (ages 4-6 weeks) were inoculated s.c. with 10 million U87MG human glioma cells in the right flank. When tumor volumes reached approximately 100 mm3 (approximately 6-8 days), i.t. injections of saline, DAB389IL2, or DAB389EGF 1, 3, 5 or 10 microg in 50 microL were given every other day for three to six doses. Animals were monitored twice daily and tumor measurements were made by calipers.

RESULTS

The maximal tolerated dose (MTD) of DAB389EGF was 3 microg every other day. Above the MTD, animals experienced loss of activity, reduced oral intake, and dehydration. Blood chemistries confirmed elevated blood urea nitrogen, creatinine, aspartate transaminase, and alanine transaminase. Histopathology revealed renal tubular necrosis. At the MTD, tumor regression was seen in all animals. Relapses occurred in 4 of 16 (25%) of animals after 1 month. These tumors contained EGF receptor, were sensitive in vitro to DAB389EGF, and responded to a second course of i.t. DAB389EGF.

CONCLUSIONS

DAB389EGF fusion protein shows in vivo antiglioma efficacy in a s.c. tumor model and warrants further preclinical testing in an i.c. tumor model for eventual treatment of patients with recurrent or refractory EGF receptor-positive glioblastoma multiforme.

[Experimental study of targeting therapy of breast cancer with 131I-labeled epidermal growth factor]

OBJECTIVE

To investigate the effectiveness of (131)I-epidermal growth factor (EGF) on the proliferation of a heterologous graft in nude mice bearing human breast infiltrating duct carcinoma.

METHODS

EGF/HAS was labeled with (131)I by chloramines-T method. Human breast cancer xenografts with positive EGFR expression were established in nude mice. The nude mice were injected with normal saline, Epirubicin Hydrochloride, (131)I-EGF, (131)I-HAS, (131)I intravenously and (131)I-EGF intratumoral administration respectively. The tumor growth inhibition rate was determined by measurement of tumor volume. Different examinations were carried out.

RESULTS

There was remarkable significant difference of tumor volumes at 26th day among (131)I-EGF trial groups, (131)I, (131)I-HAS, and the negative control group. The tumor growth inhibition rate of (131)I-EGF trial groups was 82.0%, 80.7% respectively. Compared with the negative control group, the (131)I-EGF trial groups remarkably suppressed the growth of tumor (P < 0.05). Irreversible destruction of tissues in (131)I-EGF groups was observed under light and electron microscope. There was no evidence of hepatotoxicity, renal toxicity and myelotoxicity in nude mice bearing human breast cancer given (131)I-EGF over a 4-wk observation period.

CONCLUSION

(131)I-EGF has obvious antitumor effects on a heterologous graft in nude mice bearing human breast infiltrating duct carcinoma, with little obvious side effects.

Medical therapy for ulcerative colitis: the state of the art and beyond

Ulcerative colitis (UC) is an idiopathic inflammatory condition of the large intestine. Recent advances in our understanding of the pathogenesis of UC have led to the development of novel treatments for this often debilitating condition. Aside from aminosalicylates and corticosteroids, drugs that have been used for decades in the treatment of UC, biologic agents, in addition to medications targeting specific effector mechanisms involved in the inflammatory cascade, have been used in patients with UC with varying degrees of success. Clinicians have never had as many therapeutic options for UC as they do today. Herein we review the variety of treatment options, both standard and investigational, that are available for patients with UC.

[Growth factors and wound healing: review and prospect in recent ten years]

OBJECTIVE

To review the current condition of growth factors and their application to clinical treatment of acute and chronic wounds.

METHODS

Data from the literature and Medline were analyzed according to their different uses in acute and chronic wounds. Their potential side-effects were studied.

RESULTS

All data showed that wound healing time in acute and chronic wounds was accelerated and wound healing quality was improved after treatment with growth factors. No side-effect was observed.

CONCLUSION

The efficacy and safety of growth factors in improving wound healing were confirmed. However, some reconsideration about potential problems of growth factors must be made to apply them clinically in the future.

The use of recombinant human epidermal growth factor (rhEGF) in a gentleman with drug-induced Steven Johnson syndrome

A case of drug-induced Steven Johnson syndrome in a gentleman is reported. Its course of treatment with rhEGF was compared to conventional treatment in historical control.

Topical disposition of two strengths of a 125I-rhEGF jelly in rat skin wounds

Growth factors have proved to be an effective therapeutic strategy. However, some controversies have arisen concerning their efficacy in topical wound treatments. Stabilization of epidermal growth factors at the wound site and long-lasting receptor occupancy are important factors for wound repair. This study evaluated the cumulative profiles of two jellies containing 10 or 20 microg of 125I-rhEGF per gram of jelly, in a rat full-thickness skin lesion model. The prolonged time-courses at the wound sites for both strengths compared with saline solutions previously evaluated using a similar skin lesion model are reported. It seems that these two topical formulations that provide more sustained amounts of 125I-rhEGF over the period of sampling, would probably achieve the required wound healing response in terms of cell proliferation, collagen deposition and protein synthesis. Further studies need to be developed in order to elucidate whether such an in vivo disposition pattern is consistent with an earlier and stronger promotion of wound healing events.

Wound healing: the role of growth factors

Wound healing is a complex biological process that requires cellular interactions between a variety of cells, including fibroblasts, myofibroblasts, smooth muscle cells, endothelial cells, keratinocytes and immune cells. These interactions are mediated by numerous factors such as growth factors, hormones, blood components and second messengers. Several growth factors that are released at the wound site are presumed to be necessary for wound healing. These include epidermal growth factor (EGF), fibroblast growth factor (FGF), insulin-like growth factor (IGF), keratinocyte growth factor (KGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF) and vascular endothelial growth factor (VEGF). The clinical use of growth factors to stimulate the healing of wounds is currently being investigated. Several growth factors, including PDGF, FGF-2, IGF and KGF, have been used in clinical trials, and PDGF is currently approved for use in human medicine.

Effect of epidermal growth factor infusion on fetal rabbit intrauterine growth retardation and small intestinal development

BACKGROUND/PURPOSE

Intrauterine growth retardation (IUGR) infants have impaired gastrointestinal function with resultant feeding difficulties and predisposition to necrotizing enterocolitis. Supplemented amniotic fluid swallowed by the developing fetus is a potential prenatal treatment for IUGR. Rabbits have naturally occurring IUGR fetuses based on uterine position. To determine intestinal response to epidermal growth factor (EGF) infusion, this rabbit model of IUGR was studied.

METHODS

Eight pregnant rabbits underwent placement of intraamniotic catheters into 2 normal and 2 IUGR fetuses per mother on gestational day 24 of a 31-day gestation. Miniosmotic pumps infused either EGF (about 300 microg/kg/d) or control solution forming 4 study groups (EGF-Favored [Fav] v. Cont-Fav; EGF-IUGR v. Cont-IUGR). On gestational day 31, the fetal gastrointestinal tracts were harvested for analysis. Intestinal epithelial cell proliferation was studied by 5-bromo-2-deoxyuridine (BrdU) incorporation, villus heights were measured, and EGF mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR). Statistical analysis was performed using Students' t test.

RESULTS

Fetal survival rate was 87%. EGF-IUGR fetal weights were increased compared with Cont-IUGR fetuses. EGF infusion significantly increased IUGR fetal small intestinal villus height and BrdU-positive small intestinal (SI) crypt cells, all approaching Cont-Fav levels. EGF mRNA was expressed throughout the gastrointestinal tract.

CONCLUSIONS

Supplemental amniotic EGF normalizes fetal weight and intestinal proliferation in the IUGR fetal rabbit. The inclusion of EGF in supplemental amniotic feeding solutions is supported.

[177Lu]Bz-DTPA-EGF: Preclinical Characterization of a Potential Radionuclide Targeting Agent Against Glioma

Patients with glioblastoma multiforme have a poor prognosis due to recurrences originating from spread cells. The use of radionuclide targeting might increase the chance of inactivating single tumor cells with minimal damage to surrounding healthy tissue. As a target, overexpressed epidermal growth factor receptors (EGFR) may be used. A natural ligand to EGFR, the epidermal growth factor (EGF) is an attractive targeting agent due to its low molecular weight (6 kDa) and high affinity for EGFR. 177Lu (T(1/2) = 6.7 days) is a radionuclide well suited for treatment of small tumor cell clusters, since it emits relatively low-energy beta particles. The goal of this study was to prepare and preclinically evaluate both in vitro and in vivo the [177Lu]Bz-DTPA-EGF conjugate. The conjugate was characterized in vitro for its cell-binding properties, and in vivo for its pharmacokinetics and ability to target EGFR. [177Lu]Bz-DTPA-EGF bound to cultured U343 glioblastoma cells with an affinity of 1.9 nM. Interaction with EGFR led to rapid internalization, and more than 70% of the cell-associated radioactivity was internalized after 30 minutes of incubation. The retention of radioactivity was good, with more than 65% of the 177Lu still cell-associated after 2 days. Biodistribution studies of i.v. injected [177Lu]Bz-DTPA-EGF in NMRI mice demonstrated a rapid blood clearance. Most of the radioactivity was found in the liver and kidneys. The liver uptake was receptor-mediated, since it could be significantly reduced by preinjection of unlabeled EGF. In conclusion, [177Lu]Bz-DTPA-EGF seems to be a promising candidate for locoregional treatment of glioblastoma due to its high binding affinity, low molecular weight, and ability to target EGFR in vivo.

A kit formulated under good manufacturing practices for labeling human epidermal growth factor with 111In for radiotherapeutic applications

Our goal was to design and manufacture a kit under good manufacturing practices (GMP) for the preparation of (111)In-DTPA-hEGF Injection, a novel targeted radiotherapeutic agent for advanced epidermal growth factor receptor (EGFR)-positive breast cancer.

METHODS

Human EGF (hEGF) was derivatized with diethylenetriaminepentaacetic acid (DTPA) and then purified by size-exclusion chromatography and ultrafiltration. Kits were prepared by dispensing 0.25 mg (1 mL) of DTPA-hEGF in 1 mol/L sodium acetate buffer [pH 6.0] into single-dose glass vials. Raw materials were pharmacopoieal or reagent grade according to the American Chemical Society and were tested for identity and purity. Kits were tested for protein concentration, purity and homogeneity (sodium dodecyl sulfate polyacrylamide gel electrophoresis and size-exclusion high-performance liquid chromatography), pH, clarity and color, volume, DTPA substitution, labeling efficiency, receptor binding to MDA-MB-468 human breast cancer cells, and sterility and apyrogenicity. (111)In-DTPA-hEGF Injection was tested for pH, radionuclidic and radiochemical purity, clarity and color, and sterility and apyrogenicity.

RESULTS

Four lots of kits and 8 lots of (111)In-DTPA-hEGF Injection passed all quality specifications. The labeling efficiency was 94%-99% with 115-773 MBq (111)In chloride added to a single kit. (111)In-DTPA-hEGF exhibited preserved receptor binding against MDA-MB-468 cells (affinity constant [K(a)], 0.9-1.1 x 10(7) L/mol; maximum number of binding sites per cell [B(max)], 1.1-2.2 x 10(6) sites per cell). In addition, labeling of aliquots of the kit suggested that a single vial could be labeled with up to 3,083 MBq (111)In while maintaining a radiochemical purity of >90%. Kits were stable for >90 d and (111)In-DTPA-hEGF Injection was stable for >24 h stored at 4 degrees C.

CONCLUSION

The kit formulation is suitable for preparing (111)In-DTPA-hEGF Injection for a phase I clinical trial in patients with advanced EGFR-positive breast cancer. Establishment of the GMP processes for (111)In-DTPA-hEGF Injection provides a useful example of manufacturing biotechnology-based investigational radiopharmaceuticals in an academic environment for early phase I clinical trials.

[An early comprehensive prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation]

OBJECTIVE

To study an early comprehensive prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation.

METHODS

From January 1990 to December 2001, 72 cases of patients with delayed fluid resuscitation were admitted to our burn department. Two different periods were divided and analyzed retrospectively. The first period was from January 1990 to December 2001 and the span of the second period was from January 1995 to December 2001.

RESULTS

(1)The mortality rate and incidence of sepsis in the second period (6.5 percent and 17.4 percent) were significantly lower than those of the first period (23.0 percent and 57.7 percent, P<0.05 and P<0.01). (2)The time of wound healing in the second period was (1.9+/-0.9) hours, it was lower than that of the first period (6.6+/-2.5) hours. (3)The serum contents of tumor necrosis factor (TNF) and blood lactic acid (BLA) were increased at all times in two periods and were markedly increased in the first period (all P<0.01).

CONCLUSION

Our data demonstrated that measures adopted in the second period for patients with delayed fluid resuscitation, including early excision, early rapid adequate resuscitation, early enteral feeding, increased immunity function, early applying antibactials, xenotransfusion of ultraviolet-irradiated blood, application of recombinant human-growth factor (rh-GH), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), are beneficial to the prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation.

Sustained local application of low-dose epidermal growth factor on steroid-inhibited colonic wound healing

BACKGROUND/PURPOSE

The effects of locally administered low-dose epidermal growth factor in a steroid-inhibited wound healing were investigated in a rat model.

METHODS

Long-acting release of epidermal growth factor was enabled using microspheres embedded in gelatin sponge. Study groups consisted of 60 rats with 10 in each: colonic anastomosis only (C), plus pure gelatin sponge (CG), plus epidermal growth factor loaded sponge (CE), colonic anastomosis and steroid (S), plus gelatine sponge (SG), and plus epidermal growth factor-loaded gelatine sponge (SE) groups. Bursting pressure and wound hydroxy-proline content were measured. Bursting sites were recorded. Collagen deposits, inflammation, and foreign body reactions were evaluated.

RESULTS

Bursting pressure and hydroxy-proline contents were found lowest in the S and highest in the CE groups (P <.01). There was almost no difference between C and SE groups. Bursts were encountered in peri-anastomotic normal colon sites in the nonsteroid-treated C, CG, and CE groups. They were noted overwhelmingly at the anastomosis in steroid-inhibited S, SG, and SE groups. Histopathology results showed a standstill at the inflammatory phase of healing in S and SG groups. The best healing was observed in the CE group. Degree of collagen accumulation was well correlated with bursting pressure and hydroxy-proline content data with a negligible foreign body reaction to gelatine sponge.

CONCLUSIONS

Continuous local epidermal growth factor administration by microspheres in gelatin increases wound collagen and further enhances healing in colonic anastomoses even with steroid inhibition.

Post-ischemic administration of heparin-binding epidermal growth factor-like growth factor (HB-EGF) reduces infarct size and modifies neurogenesis after focal cerebral ischemia in the rat

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a hypoxia-inducible, neuroprotective protein that also stimulates proliferation of neuronal precursor cells. Accordingly, HB-EGF may contribute to recovery from cerebral injury through direct neuroprotective effects, by enhancing neurogenesis, or both. When administered by the intracerebroventricular route 1-3 days after focal cerebral ischemia in adult rats, HB-EGF decreased the volume of the resulting infarcts and reduced post-ischemic neurological deficits. HB-EGF also increased the incorporation of bromodeoxyuridine into cells expressing the immature neuronal marker protein TUC-4 in the dentate subgranular and rostral subventricular zones, consistent with increased proliferation of neuronal precursors. However, HB-EGF decreased the number of newborn neurons that migrated into the ischemic striatum, perhaps partly because reduction of infarct size by HB-EGF also reduced the stimulus to migration. To determine if HB-EGF might also directly inhibit migration of neuronal precursors, we co-cultured subventricular zone (SVZ) explants treated with HB-EGF or vehicle together with hypoxic cerebral cortical explants, and measured cell migration from the former toward the latter. HB-EGF reduced directed migration of SVZ cells toward the cortical explants, possibly due to a local chemoattractant effect on neuronal precursor cells, which may be mediated through the HB-EGF-specific receptor, N-arginine dibasic convertase. The delayed neuroprotective effect of HB-EGF may have implications for efforts to prolong the therapeutic window for intervention in stroke.

Epidermal growth factor and necrotizing enterocolitis

As the number of extremely low-birth-weight infants increases,necrotizing enterocolitis remains a critical eminent problem. Supplementation of enteral feeds with biologically active substances normally present in breast milk, such as epidermal growth factor, seems to be a logical and safe way to reduce the incidence of intestinal inflammation and necrotizing enterocolitis. Continuing basic research and clinical studies are essential before epidermal growth factor can be introduced as an efficient therapeutic approach in the treatment of neonatal necrotizing enterocolitis.

Medical management of ulcerative colitis

Patients with ulcerative colitis have no increased mortality compared to population controls and the disease can be cured be colectomy. This review concentrates on the medical management of ulcerative colitis including the management of active colitis, acute severe colitis and first presentation of colitis, maintenance of remission and long-term complications.

Combined gastrin and epidermal growth factor treatment induces islet regeneration and restores normoglycaemia in C57Bl6/J mice treated with alloxan

AIMS/HYPOTHESIS

Increasing beta-cell mass and/or function could restore glucose homeostasis in diabetes mellitus. Hitherto, trophic factors for beta-cell regeneration after toxic events have been difficult to identify. We evaluated the application of gastrin and epidermal growth factor after alloxan-induced pancreatic beta-cell damage.

METHODS

After alloxan treatment (70 mg/kg), mice were implanted with Alzet osmotic minipumps releasing gastrin and epidermal growth factor for one week. We monitored glycaemia, did histological analyses of the pancreata and quantified pancreatic beta-cell mass and insulin content.

RESULTS

Alloxan treatment alone resulted in a persisting hyperglycaemic state. Combined gastrin and epidermal growth factor treatment restored normoglycaemia in 3 days, an effect which seemed permanent. Glucose tolerance tests showed normal glucose responsiveness. Gastrin on its own and epidermal growth factor on its own did not alleviate hyperglycaemia. Islet mass, islet density and pancreatic insulin content were higher in mice treated with gastrin and epidermal growth factor than in untreated mice with persisting hyperglycaemia. In normoglycaemic control mice treatment with gastrin and epidermal growth factor did not affect these parameters. We detected transitional cytokeratin-positive ductal to endocrine insulin-expressing cells and noted increased ductal but not beta-cell proliferation.

CONCLUSIONS/INTERPRETATION

Our results show that combined treatment with gastrin and epidermal growth factor can induce sufficient regeneration of a functional islet mass to restore glucose homeostasis.

Combination fusion protein therapy of refractory brain tumors: demonstration of efficacy in cell culture

Primary brain tumors including anaplastic astrocytomas and glioblastoma multiforme are difficult to treat because of their locally invasive nature and relative resistance to chemotherapy and radiation therapy. Novel agents that can kill multi-drug resistant tumor cells and reach tumor cells at distant sites in the brain are needed. One such class of agents is fusion proteins which consist of brain-tumor-selective peptide ligands fused to peptide toxins. The ligand directs the protein to the glioma cell surface; the peptide toxin is then internalized into the cell, translocates to the cytosol and catalytically inactivates protein synthesis leading to cell death. Fusion proteins are toxic to multi-drug resistant brain tumor cells. Because of the large molecular weight of these molecules, a unique delivery system has been developed--convection-enhanced delivery (CED). The method creates a bulk flow which supplements diffusion and achieves drug concentrations in the brain parenchyma orders of magnitude greater than by systemic administration. Patients with recurrent glioma treated with individual fusion protein CED have obtained clinical remissions lasting years. However, toxicities to normal brain have been observed and relapses ultimately occurred. To address the clinical need of these patients and improve upon the therapeutic index observed to date with single fusion protein CED, we generated a novel fusion protein DAB389EGF and tested it in combination with another active fusion protein, IL13PE38QQR. We observed potent glioma cytotoxicity with each fusion protein and synergistic toxicity with the combination. Further, brain tumor cells showed heterogeneous expression of individual receptors suggesting that the combination--DAB389EGF and IL13PE38QQR may show improved efficacy and should undergo further preclinical development for therapy of patients with relapsed high-grade gliomas.

Effect of epidermal growth factor on pulmonary hypoplasia in experimental diaphragmatic hernia

BACKGROUND/PURPOSE

Currently, tracheal occlusion (TO) is a potent stimulus for fetal lung growth but also a rather invasive and high-risk procedure. The aim of this study was to investigate a new and much less invasive therapeutic strategy, namely the maternal intraperitoneal administration of epidermal growth factor (EGF) and its effect on pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia (CDH) rat model, especially its effect on type II pneumocytes.

METHODS

CDH was induced by maternal administration of a single oral dose (100 mg) of nitrofen on day 8.5 of pregnancy. Four groups of pregnant rats were designed on day 18.5: normal control (n = 4), CDH (n = 4), CDH plus Dex (n = 4), CDH plus EGF (n = 8). All fetuses were delivered by cesarean section on day 21. Accordingly, there were 4 groups of fetuses: normal controls (n = 33), nitrofen-induced CDH (n = 19), CDH plus Dex treatment (n = 15), and CDH plus EGF treatment (n = 24). Lung tissue weight (LW) and body weight (BW) of each fetus were recorded, lung histologic and morphometric evaluations were performed, and image analysis was combined after lung processing. Transmission electron microscopy was used for ultrastructural observation, especially type II pneumocytes.

RESULTS

CDH was observed in 58 of the 94 rat fetuses (61.7%). Lw/Bw of CDH group was significantly lower than those of Dex and EGF (P <.05). The lungs of CDH fetuses showed marked hypoplasia, in contrast to improved mesenchymal differentiation in that of Dex and EGF fetuses. Statistical differences of these morphologic parameters (RAC, MTBD, interstitial%, and alveoli%) were found (P <.05). As to ultrastructural features, type II cells of CDH lungs had few if any lamellar bodies and cytoplasmic organelles, and showed evidence of abundant glycogen granules. The sparse type II cells also showed cytoplasmic degenerative changes. By contrast, type II cells of EGF lungs showed numerous mitochondria, abundant lamellar bodies (surfactant) and deficiency of glycogen granules, and displayed prominent microvillous projections and pitlike depressions. The density of type II pneumocyte were 65 +/- 4.5, 31 +/- 3.1, and 8 +/- 1.5 for EGF, Dex, and CDH, respectively (EGF v Dex, P <.05; EGF v CDH, P < 0.01).

CONCLUSIONS

Compared with TO, prenatal EGF administration as a much less-invasive therapeutic strategy had shown marked improvement in pulmonary hypoplasia and promotion of type II pneumocyte differentiation in the nitrofen-induced CDH rat model. Thus, EGF could improve the prognosis of CDH by means of promoting pulmonary hypoplasia and improving the surfactant deficiency, which suggested a potential role in the clinical treatment of CDH.

[The study of peptide effect in the mechanisms of angiogenesis and forming of microenvironment of the tumors in old rats]

The experiments were performed in rats with transplanted sarkoma M-1. The injections of synthetic peptide vilon at the doses 0.5 mcg sigificantly increased the apoptosis of tumor cells in the experiment as compared to the control group. So vilon has possessed the oncomodulating action on the transplanted carcinoma. The injections of epigene lead to the inhibition of the sarcoma growth due to the development of the hemorragic necrosis and apoptosis increased. The results obtained suggested that vilon and epigene are the perspective preparates in the cancer therapy.

Growth factors: the wound healing therapy of the future

'Growth factors' is an umbrella term used to describe a variety of chemical messengers found in a wide range of tissues, which have a number of functions including the regulation of cell and tissue growth and development. Several growth factors have been proposed as ideal agents to promote wound healing. This review discusses their functions and how they can be applied in the management of chronic wounds.

Combined effect of gefitinib ('Iressa', ZD1839) and targeted radiotherapy with 211At-EGF

The EGFR-TKI (epidermal growth factor receptor tyrosine kinase inhibitor) gefitinib ['Iressa' (trademark of the AstraZeneca group of companies), ZD1839] increases the cellular uptake of radiolabelled epidermal growth factor (EGF). We investigated gefitinib treatment combined with astatine-211 EGF targeting in vitro using two cell lines expressing high levels of EGFR: A431 (sensitive to gefitinib) and U343MGaCl2:1 (resistant to gefitinib). In both cell lines, the uptake of 211At-EGF was markedly increased by concomitant treatment with gefitinib. Survival was investigated using both a clonogenic survival assay and a cell growth assay. Combined gefitinib and 211At-EGF treatment reduced the survival of U343 cells 3.5-fold compared with 211At-EGF alone. In A431 cells, 211At-EGF treatment resulted in very low survival, but combined treatment with gefitinib increased the survival by about 20-fold. These results indicate that combined treatment with gefitinib might increase the effect of ligand-mediated radionuclide therapy in gefitinib-resistant tumours and decrease the effect of such therapy in gefitinib-sensitive tumours.

Buccal mucosal ulcer healing effect of rhEGF/Eudispert hv hydrogel

We have studied the effect of rhEGF on the buccal mucosal ulcer healing. rhEGF was rapidly degraded upon incubation with the hamster buccal mucosal homogenates; The degradation of rhEGF was significantly inhibited by sodium lauryl sulfate (SLS). Eudispert hv hydrogel and Polycarbophil 974P hydrogel were prepared for rhEGF delivery and their mucoadhesiveness was measured by the Instron method. The mucoadhesive force of Eudispert hv was significantly greater than that of Polycarbophil 974P. Moreover, rhEGF in Eudispert hv hydrogel remained stable for about 2 months. To evaluate the ulcer healing effect of rhEGF, the buccal mucosal ulcer was induced in golden hamsters using acetic acid. At 24 h after administration of rhEGF/Eudispert hv hydrogel, the ulcerous area was decreased compared with rhEGF solution and, as a result, the curative ratio was 36.8 +/- 5.68%. By the addition of SLS (0.5%) to Eudispert hv hydrogel, the curative ratio increased 1.5 times. The mechanism of the action was probably due to a combination of protection of the drug against proteases present in mucosa and prolongation of the release of rhEGF from the formulation at the site of action.

Difference in responsiveness of human esophageal squamous cell carcinoma lines to epidermal growth factor for MMP-7 expression

Expression of MMP-7 in human esophageal squamous cell carcinoma lines (TE-9 and -10) was investigated. Under normal culture conditions, immunocytochemical staining and enzymography demonstrated the production of MMP-7 in their cytoplasm and its gelatinolytic activity in the medium of TE-9 and -10 cell cultures. When EGF was added to the cultures, Western blotting and RT-PCR analysis showed a dose-dependent increase in the amount of MMP-7 synthesized in the TE-9 cells, whereas in TE-10 cells, EGF failed to stimulate MMP-7 production. For luciferase reporter analysis of MMP-7 transcription, pMMP7LucWI (1132-bp) and pMMP7LucWII (334-bp) were cloned in the luciferase pGL3-basic vector. The promoter activity was enhanced from 1.5- to 2-fold by the addition of EGF to TE-9 cells transfected with pMMP7LucWI or WII, even though the response was low as compared with that of 12-O-tetra-decanoyl-phorbol-13-acetate (TPA); and in TE-10 cells, only TPA enhanced the promoter activity of MMP-7. Luciferase promoter analysis using a pMMP7WII mutant series revealed that the AP-1 site was essential for transcription of the MMP-7 gene in TE-9 cells, and Tcf-I was also an important site, and that to a lesser degree, Tcf-II and PEA3s participated in the transcription of the MMP-7 gene in these cells. Unlike the results with TE-9 cells, in TE-10 cells, EGF failed to stimulate transcription of the MMP-7 gene; and up-regulation of the promoter activity by TPA was dependent on the AP-1 site and to lesser degree, on Tcf-I and Tcf-II. These results suggest that EGF plays also an important role in MMP-7 production of TE-9 cells and that there is a difference not only in EGF-intracellular signaling system but also in regulation mechanisms of MMP-7 transcription by beta-catenin-Tcf and/or PEA3 system between these 2 carcinoma lines.

Epidermal growth factor enemas with oral mesalamine for mild-to-moderate left-sided ulcerative colitis or proctitis

BACKGROUND

Epidermal growth factor (EGF) is a potent mitogenic peptide produced by salivary glands. We examined whether EGF enemas are an effective treatment for active left-sided ulcerative colitis and ulceration limited to the rectum (proctitis).

METHODS

In a randomized, double-blind clinical trial conducted at Leicester Royal Infirmary, 12 patients with mild-to-moderate left-sided ulcerative colitis received daily enemas of 5 microg of EGF in 100 ml of an inert carrier and 12 received daily enemas with carrier alone for 14 days. All also began to receive 1.2 g of oral mesalamine per day or had their dose increased by 1.2 g per day. Patients were assessed clinically at 0, 2, 4, and 12 weeks and by sigmoidoscopy and biopsy at 0, 2, and 4 weeks. The primary end point was disease remission (defined by a St. Marks score of 4 or less without sigmoidoscopic evidence of inflammation) at two weeks. Secondary end points were clinically significant improvements in disease activity (defined by a decrease of more than 3 points in the St. Marks score or the ulcerative colitis disease-activity index) at two and four weeks. Analyses were performed according to the intention-to-treat principle.

RESULTS

After two weeks, 10 of the 12 patients given EGF enemas were in remission, as compared with 1 of 12 in the control group (83 percent vs. 8 percent, P<0.001). At the 2-week assessment, disease-activity scores, sigmoidoscopic score, and histologic scores were all significantly better in the EGF group than in the placebo group (P<0.01 for all comparisons), and this benefit was maintained at 4 weeks and at 12 weeks.

CONCLUSIONS

This study provides preliminary data suggesting that EGF enemas are an effective treatment for active left-sided ulcerative colitis.

[A comparative study on burn wound healing treated by different methods of recombinant human epidermal growth factor]

OBJECTIVE

To explore an optimal method of recombinant human epidermal growth factor(rhEGF) application on the burn wounds of superficial II degree and profound II degree for accelerating its healing.

METHODS

There were 180 burn wounds in 60 patients with the self-corresponding wound of the same degree as controls. The wounds of all patients were divided three regions(A, B, C). The wounds were treated once a day with 1% SD-Ag in region A as controls, with rhEGF(40 U/cm2) in region B, and with a combination of rhEGF(40 U/cm2) and Su Yu Ping (5 g) in region C. The wound healing time was recorded and compared.

RESULTS

In regions A, B and C, the healing time of superficial II degree wound was (13.20 +/- 2.40) days, (10.20 +/- 2.20) days and (8.72 +/- 2.31) days (P < 0.01); that of profound II degree wound was (20.10 +/- 3.40) days, (17.20 +/- 3.12) days and (15.10 +/- 3.81) days respectively (P < 0.01, P < 0.05). The healed wound of profound II degree was elastic and tough in regions B and C, while that was not elastic and tough, and congestive in region A.

CONCLUSION

The above results indicate that rhEGF can enhance burn wound healing markedly and that a combination rhEGF and Su Yu Ping has more significant effect than rhEGF alone and is recommended for clinical application.

Polyethylene glycol-coated liposomes for oral delivery of recombinant human epidermal growth factor

The present study was to investigate the feasibility of oral delivery of recombinant human epidermal growth factor (rhEGF). Polyethylene glycol (PEG)-coated liposomes containing rhEGF was prepared and evaluated for their stability and permeability in Caco-2 cells. In the animal study, we also determined plasma concentration and gastric ulcer healing effect after oral administration of rhEGF liposomes or the solution. Encapsulation of rhEGF into liposomes, suppressed the degradation in Caco-2 cell homogenate compared with the solution. The flux of rhEGF from dipalmitoylphosphatidylcholine (DPPC) liposome across Caco-2 cell monolayer from the apical to basolateral side was three times greater than that from phosphatidylcholine (PC) liposome or the solution. After oral administration of rhEGF liposomes or the solution in rats, the area under the concentration-time curve (AUC) of rhEGF increased 1.7- and 2.5-fold for PC and DPPC liposomes, respectively. The gastric ulcer healing effect was significantly increased in DPPC liposome compared with PC liposome and the solution. The enhanced curative ratio of rhEGF encapsulated into DPPC liposome may be due to the resistance to enzyme degradation, higher permeability and increased plasma AUC. Therefore, PEG-coated liposomes containing rhEGF could be used as an oral delivery formulation with enhanced encapsulation efficiency.

[Clinical observation of the long-term effects of rhEGF on deep partial-thickness burn wounds]

OBJECTIVE

To evaluate the safety and long-term effect of recombinant human epithelial growth factor (rhEGF) on deep partial-thickness burn wounds.

METHODS

Thirty-seven burn patients were enrolled in this study and were observed by randomized, double-blinded and placebo-controlled protocol. An area of deep partial-thickness burn wounds from each patient was divided into control (C) and treatment (T) portions. The wound in C was treated with normal saline while that in T with rhEGF. The patients were followed-up for 1 and 4 years after wound healing. The healed wounds were evaluated by modified Vancouver scar scale in terms of scar index (SI).

RESULTS

1 year after wound healing, it was found that the SI in T group (7.19 +/- 1.67) was obviously lower than that in C group (8.92 +/- 1.78, P < 0.01). The SI in T group (6.12 +/- 1.54) was still evidently lower than that in C group (8.09 +/- 1.81, P < 0.01) four years after wound healing. There were no signs of development of tumor or cancer in all the tested burn wound areas.

CONCLUSION

External application of rhEGF might be beneficial to the healing quality of deep partial-thickness burn wound with less scar formation and better long-term effects, and it is safe.

Human epidermal growth factor enhances healing of diabetic foot ulcers

OBJECTIVE

To study the healing effect of recombinant human epidermal growth factor (hEGF) on diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

A total of 127 consecutive patients were screened and 61 diabetic subjects were recruited into this double-blind randomized controlled study. Predetermined criteria were used for diagnosis and classification of the diabetic wound. The patients were randomized into three groups. All patients attended our Diabetes Ambulatory Care Center every other week for joint consultation with the diabetologist and the podiatrist. Group 1 (control) was treated with Actovegin 5% cream (Actovegin), group 2 with Actovegin plus 0.02% (wt/wt) hEGF, and group 3 with Actovegin plus 0.04% (wt/wt) hEGF. The study end point was the complete closure of the wound. Failure to heal was arbitrarily defined as incomplete healing after 12 weeks.

RESULTS

Final data were obtained from 61 patients randomly assigned into three groups. The mean ages of the patients, wound sizes, wound duration, metabolic measurements, and comorbidities were comparable within groups, except that group 3 had more female patients. Mean follow-up for the patients was 24 weeks. Data were cutoff at 12 weeks, and results were analyzed by intention to treat. After 12 weeks, in group 1 (control) eight patients had complete healing, two patients underwent toe amputation, and nine had nonhealing ulcers. In group 2 (0.02% [wt/wt] hEGF) 12 patients experienced wound healing, 2 had toe amputations, and 7 had nonhealing ulcers. Some 20 of 21 patients in group 3 (0.04% [wt/wt] hEGF) showed complete wound healing. Healing rates were 42.10, 57.14, and 95% for the control, 0.02% (wt/wt) hEGF, and 0.04% (wt/wt) hEGF groups, respectively. Kaplan-Meier survival analysis suggested that application of cream with 0.04% (wt/wt) hEGF caused more ulcers to heal by 12 weeks and increased the rate of healing compared with the other treatments (log-rank test, P = 0.0003).

CONCLUSIONS

Our data support the contention that application of hEGF-containing cream, in addition to good foot care from a multidisciplinary team, significantly enhances diabetic foot ulcer wound healing and reduces the healing time.

The effects of hyaluronic acid, epidermal growth factor, and mitomycin in an experimental model of acute traumatic tympanic membrane perforation

HYPOTHESIS

The goal of this study was to evaluate the effects of hyaluronic acid, epidermal growth factor, and mitomycin C on the healing of acute experimental traumatic perforations of the tympanic membrane.

BACKGROUND

Most acute perforations of the tympanic membrane heal spontaneously. However, some form of surgical treatment (i.e., myringoplasty) is needed for nonhealing perforations. Because the closure occurs by squamous epithelial migration, drugs that stimulate this regenerative process may aid in the closure of the perforation, obviating the need for more extensive treatments.

METHODS

Bilateral perforations of the tympanic membrane were created in 30 rats, divided into three groups (A, B, C). The perforations in the right ears were treated with hyaluronic acid, epidermal growth factor, or mitomycin C. Those in the left ears were left untreated for comparison. To examine the healing process in different periods, 5 animals were killed in each group at days 3, 5, 7, 9 and 14. The other 5 animals in each group were observed daily to determine the duration of perforation closures. Thirty surgical specimens (5 right sides from each group and all 15 left sides in all groups) were histopathologically examined for tympanic membrane thickness, fibroblastic reaction, neovascularization, and crust morphology.

RESULTS

Hyaluronic acid and epidermal growth factor applications significantly shortened the healing in acute experimental traumatic perforations of the tympanic membrane (p = 0.0432); however, the difference between them was not significant (p = 0.3160). On the other side, tympanic membrane perforations treated with topical mitomycin C showed no evidence of closure. There were no significant differences in the histologic parameters between the treated groups and their contralateral control ears.

CONCLUSION

Hyaluronic acid and epidermal growth factor accelerated the closure of acute tympanic membrane perforations in rats. This may make them clinically useful in augmenting the efficiency of conservative treatments of acute perforations of the tympanic membrane.

Cellular retention of radioactivity and increased radiation dose. Model experiments with EGF-dextran

Targeting of tumor cells with radiolabeled biomolecules is a possible approach to inactivate disseminated tumor cells. However, rapid degradation of the biomolecules after cellular internalization and subsequent excretion of the radioactivity is a problem. We studied the possibility of using dextran as a carrier of radionuclides to improve the intracellular retention. An EGF-dextran conjugate, aimed for targeting of tumor cells overexpressing the EGF-receptor, was used as model. Retention tests were performed with (125)I on different parts: [(125)I]-EGF-dextran-[(125)I], [(125)I]-EGF-dextran and EGF-dextran-[(125)I]. Comparisons were made with [(125)I]-EGF. The radiolabeled compounds were incubated with cultured glioma cells for different times. The cellular retention of radioactivity was then measured for up to 24 h. Expected radiation doses at the cellular level were calculated assuming that (131)I, instead of (125)I, was coupled to EGF and EGF-dextran. The results indicated that the EGF-part of the conjugate was degraded and the EGF-attached radioactivity was rapidly excreted, whereas radioactivity on dextran was retained intracellularly to a high degree, i.e. 70-80% of the radioactivity bound to dextran was still cell-associated after 24 h. The retention after 24 h was significantly higher (p < 0.001) when the radioactivity was on the dextran instead of the EGF-part. The radiolabeled EGF-dextran had a notably high specific radioactivity; up to 11 MBq/microg. There was potential for at least hundred times increased radiation dose per receptor interaction when the radioactivity was on the dextran part. The advantage with radioactivity on the dextran part was the high cellular retention and the high specific radioactivity (higher than previously reported for other residualizing labels) without severe loss of receptor specific binding. Thus, dextran seems suitable as a carrier of radionuclides aimed for therapy and gives potential for a highly increased radiation dose.

EGF amplifies the replacement of parvalbumin-expressing striatal interneurons after ischemia

EGF promotes proliferation and migration of stem/progenitor cells in the normal adult brain. The effect of epidermal growth factor on neurogenesis in ischemic brain is unknown, however. Here we show that intraventricular administration of EGF and albumin augments 100-fold neuronal replacement in the injured adult mouse striatum after cerebral ischemia. Newly born immature neurons migrate into the ischemic lesion and differentiate into mature parvalbumin-expressing neurons, replacing more than 20% of the interneurons lost by 13 weeks after ischemia and representing 2% of the total BrdU-labeled cells. These data suggest that administration of EGF and albumin could be used to manipulate endogenous neurogenesis in the injured brain and to promote brain self-repair.