Injection Of Epidermal Growth Factor Research Articles

Влияние интравитреального введения эпидермального фактора роста на морфофункциональное состояние глаза кролика

Purpose. To study the morphofunctional state of the rabbit eye after intravitreal injection of epidermal growth factor. Material and methods. In an experiment on rabbits, intravitreal course administration of Eberprot-P containing recombinant epidermal growth factor (EGF) at a dose of 100 ng was carried out. 7 and 30 days after each injection, biomicroscopy and ophthalmoscopy of the eye, optical coherence tomography (OCT) of the fundus in vivo were performed. Morphological studies were performed according to the generally accepted method with staining of histological preparations with hematoxylin and eosin. The cell density of the ganglionic layer, the inner and outer nuclear layers of the retina was assessed. SPSS software for Windows was used for statistical analysis. Results. Biomicroscopic and ophthalmoscopic studies of the intraocular structures of the experimental eyes did not reveal signs of edema or intraocular inflammation, toxic or irritant effects of intravitreal injection. There were no pathological changes in the form of cataracts, Tyndall's phenomenon in the anterior chamber moisture, vitreous opacities, retinal infiltrates. According to OCT data, the retinal thickness remained unchanged: 158 ± 5µm versus the control 158 ± 3µm (p = 1.0), no retinal wrinkling effects were detected. The morphological picture of the intraocular tissues of the eye after intravitreal injection was characterized by the absence of any pathological changes in the architectonics of the layers and cellular structures of the retina. Histomorphometric analysis showed no difference in the cell density of the ganglion layer, inner and outer nuclear layers of the retina of the experimental and control eyes of animals. Conclusion. Intravitreal application of EGF in rabbits does not cause intraocular specific inflammation or any destructive effects in the retina, which indicates the potential for its clinical use in the treatment of dystrophic retinal diseases. Keywords: epidermal growth factor, retina, intravitreal injection, morphology, histomorphometry

Cytokeratin overexpression in Submandibular Salivary Glands of Rats Treated with Botulinum Toxin and Epidermal Growth Factor

Botulinum toxin (BTX) is used in different cosmetic and therapeutic procedures. In dentistry, BTX has been used successfully for management of drooling. BTX injection into salivary glands has damaging adverse effects on all components of the gland. Epidermal Growth Factor (EGF) is well known for its regenerative properties. The aim of this study was to investigate the effect of BTX injections on the submandibular salivary glands of adult female Albino rats, when administered solely or in conjunction with EGF through measuring the expression of cytokeratin in the parenchyma of the gland. Sixty rats were used in this study and were equally divided into control (saline) group, BTX group and EGF + BTX group (Combined treatment). The results obtained from this study showed that cytokeratin expression in submandibular salivary glands of rats significantly decreased after a single subcutaneous injection of 2.5 units of BTX in 0.1ml saline. However, daily intraperitoneal injections of EGF with a dose of 10 µg/Kg body weight restored normal levels of cytokeratin expression, as well as normal integrity of the submandibular salivary glands. Further studies are necessary to confirm the finding from the current study through im-munohistochemical localization of E-cadherin as well as scanning electron microscopy examination of submandibular salivary glands treated with BTX and EGF.

Intravitreal application of epidermal growth factor in non-exudative age-related macular degeneration

PurposeTo assess the safety of intravitreally applied epidermal growth factor (EGF).MethodsThe clinical interventional, prospective, single-centre, case series study included patients with age-related macular degeneration-related geographic atrophy (GA), in whom the...

Compatibility of intravitreally applied epidermal growth factor and amphiregulin

IntroductionTo examine the compatibility of intravitreally injected epidermal growth factor (EGF) and amphiregulin as EGF family member.MethodsFour rabbits (age: 4 months; body weight: 2.5 kg) received three intravitreal injections of EGF (100 ng) uniocularly in monthly intervals and underwent ocular photography, tonometry, biometry, and optical coherence tomography. After sacrificing the rabbits, the globes were histomorphometrically examined. In a second study part, eyes of 22 guinea pigs (age: 2–3 weeks) received two intravitreal administrations of amphiregulin (10 ng) or phosphate buffered solution (PBS) in 10-day interval, or were left untouched. Ten days after the second injection, the guinea pigs were sacrificed, the enucleated eyes underwent histological and immune-histological examinations.ResultsThe rabbit eyes with EGF injections versus the contralateral untouched eyes did not show significant differences in intraocular pressure (7.5 ± 2.4 mmHg vs. 6.8 ± 2.2 mmHg; P = 0.66), retinal thickness (158 ± 5 µm vs. 158 ± 3 µm; P = 1.0), cell counts in the retinal ganglion cell layer (3.3 ± 1.7 cells/150 µm vs. 3.0 ± 1.4 cells/150 µm; P = 0.83), inner nuclear layer (46.4 ± 23.2 cells/150 µm vs. 39.6 ± 6.4 cells/150 µm; P = 0.61), and outer nuclear layer (215 ± 108 cells/150 µm vs. 202 ± 47 cells/150 µm; P = 0.83), or any apoptotic retinal cells. The guinea pig eyes injected with amphiregulin versus eyes with PBS injections did not differ (P = 0.72) in the degree of microglial activation, and both groups did not differ from untouched eyes in number of apoptotic retinal cells and retinal gliosis.ConclusionsIntravitreal applications of EGF (100 ng) in rabbits nor intravitreal applications of amphiregulin (10 ng) in guinea pigs led to intraocular specific inflammation or any observed intraocular destructive effect. The findings support the notion of a compatibility of intraocular applied EGF and amphiregulin.

Recombinant human epidermal growth factor combined with vacuum sealing drainage for wound healing in Bama pigs

BackgroundVacuum sealing drainage (VSD) and epidermal growth factor (EGF) both play an important role in the treatment of wounds. This study aims to explore the effects of the combination of VSD and EGF on wound healing and the optimal concentration and time of EGF.MethodsWe tested the proliferation and migration capacity of HaCaT and L929 cells at different EGF concentrations (0, 1, 5, 10, and 100 ng/ml) and different EGF action times (2, 10, and 30 min). A full-thickness skin defect model was established using male, 30-week-old Bama pigs. The experiment included groups as follows: routine dressing change after covering with sterile auxiliary material (Control), continuous negative pressure drainage of the wound (VSD), continuous negative pressure drainage of the wound and injection of EGF 10 min followed by removal by continuous lavage (V + E 10 min), and continuous negative pressure drainage of the wound and injection of EGF 30 min followed by removal by continuous lavage (V + E 30 min). The wound healing rate, histological repair effect and collagen deposition were compared among the four groups.ResultsAn EGF concentration of 10 ng/ml and an action time of 10 min had optimal effects on the proliferation and migration capacities of HaCaT and L929 cells. The drug dispersion effect was better than drug infusion after bolus injection effect, and the contact surface was wider. Compared with other groups, the V + E 10 min group promoted wound healing to the greatest extent and obtained the best histological score.ConclusionsA recombinant human epidermal growth factor (rhEGF) concentration of 10 ng/ml can promote the proliferation and migration of epithelial cells and fibroblasts to the greatest extent in vitro. VSD combined with rhEGF kept in place for 10 min and then washed, can promote wound healing better than the other treatments in vivo.

The Effect of EGF on VEGF expression on Submandibular Salivary Gland of Albino Rats Receiving Doxorubicin

Background: Vascular endothelial growth factor (VEGF) has two prominent biological effects of inducing mitogenesis and migration of vascular endothelial cells and to produce permeability on the microvasculature. Epidermal growth factor (EGF), known by its mitogenic activity on different types of cells, could induce the proliferation and differentiation of the epithelial cells and stimulate its regeneration. Doxorubicin (DXR) is a widely used anticancer drug and is one of most commonly used chemotherapeutic drugs, however it may cause some serious complications such as toxicity in various tissues in the body.Aims: The present study aims to investigate the effect of EGF on the VEGF immunoexpression in submandibular salivary gland tissue of rats receiving Doxorubicin (DXR).Methods and Material: 30 male Albino rats, two months old and weighing 200-250 gm body weight, were divided equally into three groups as follows: Group I (control group). Group II: rats received 20 mg/kg body weight DXR as a single intra peritoneal injection. Whereas, group III: rats received the same dose of DXR and on the next day they were injected intraperitoneally with EGF in a daily dose of 10μg/kg body weight for 7 consecutive days.Submandibular salivary glands were dissected out and processed for histological investigation and immunohistochemical localization of VEGF in the glandular tissue.Statistical analysis used: ANOVA was used to compare the mean area percentage of VEGF immunostaining among the specimens of different groups followed by Tukey’s Multiple Comparison Test.Results: VEGF expression in submandibular salivary glands of rats significantly decreased after DXR injection. However, daily intraperitoneal injections of EGF restored normal levels of VEGF expression in the glandular tissue.Conclusions: EGF preserved glandular architecture after DXR injection and consequently the immunohistochemical expression of VEGF in the glands to approximately the normal level.

LEA 9. Revascularization and Growth Factor Injection: It Is Effective for Healing of Foot Ulcers

Diabetic foot ulcer (DFU) is a major health problem and remains a major cause of amputation across the world. Critical assessment of the relationship between peripheral artery disease, revascularization, and healing of DFU was performed. A new therapy has been claimed to prevent major amputations in advanced DFU. The intralesional injection of recombinant human epidermal growth factor (EGF) should often lead to satisfactory outcomes. The purpose of our study was to demonstrate the advantage of the combination of revascularization and EGF local infiltration in accelerating healing of DFU. A total of 903 patients with diabetic foot from 2005 to 2016 were reviewed. The management process was based on management of ischemia with either conventional revascularization or endoluminal angioplasty, management of infection, and appropriate wound bed preparation. During wound preparation, débridement and negative pressure wound therapy were performed. Surgery and dressing were performed according to the indications. The mean age was 61 years, with male predominance (70%), and patients were followed up for a period of 41 months. All patients had severe ischemia (Wagner grades 2, 3, and 4); 370 (40.9%) had conventional surgery, 340 (37.7%) received endovascular treatment, and 192 (21.2%) had hybrid surgery. Local care consisted of débridement associated with negative pressure wound therapy in 50 cases, and 110 received EGF injection. Total healing was obtained during an average of 5 months. Perioperative mortality was 4.7%, primary limb salvage rate was 88%, and secondary overall limb salvage was 55.7%. However, of 756 revascularized patients, only 406 were followed up. In our study, the ulcer healing time after revascularization and EGF infiltration was short compared with patients without EGF intralesional injection with an average of <4 months. Nevertheless, the amputation rate was the same in both groups. Furthermore, this was secondary to unsuccessful revascularization with bypass thrombosis, failure of angioplasty, extension of infection, and nutritional status of the patient. Diabetic foot is a debilitating disease arising from a multifactorial process; its management is complex. Our series has demonstrated the potential safety and efficacy of a combination of revascularization and EGF for the treatment and accelerated healing of DFU. Primary and secondary prevention in a multidisciplinary approach improves life and limb prognosis.

Epidermal Growth Factor Improves Intestinal Integrity and Survival in Murine Sepsis Following Chronic Alcohol Ingestion.

Epidermal growth factor (EGF) is a cytoprotective protein that improves survival in preclinical models of sepsis through its beneficial effects on intestinal integrity. Alcohol use disorder worsens intestinal integrity and is associated with increased morbidity and mortality in critical illness. We sought to determine whether chronic alcohol ingestion alters the host response to systemic administration of EGF in sepsis. Six-week-old FVB/N mice were randomized to receive 20% alcohol or water for 12 weeks. All mice then underwent cecal ligation and puncture to induce polymicrobial sepsis. Mice were then randomized to receive either intraperitoneal injection of EGF (150 μg/kg/day) or normal saline. Water-fed mice given EGF had decreased 7-day mortality compared with water-fed mice (18% vs. 55%). Alcohol-fed mice given EGF also had decreased 7-day mortality compared with alcohol-fed mice (48% vs. 79%). Notably, while systemic EGF improved absolute survival to a similar degree in both water-fed and alcohol-fed mice, mortality was significantly higher in alcohol+EGF mice compared with water+EGF mice. Compared with water-fed septic mice, alcohol-fed septic mice had worsened intestinal integrity with intestinal hyperpermeability, increased intestinal epithelial apoptosis, decreased proliferation and shorter villus length. Systemic administration of EGF to septic alcohol-fed mice decreased intestinal permeability compared with septic alcohol-fed mice given vehicle, with increased levels of the tight junction mediators claudin-5 and JAM-A. Systemic administration of EGF to septic alcohol-fed mice also decreased intestinal apoptosis with an improvement in the Bax/Bcl-2 ratio. EGF also improved both crypt proliferation and villus length in septic alcohol-fed mice. EGF administration resulted in lower levels of both pro- and anti-inflammatory cytokines monocyte chemoattractant protein-1, tumor necrosis factor, and interleukin 10 in alcohol-fed mice. EGF is therefore effective at improving both intestinal integrity and mortality following sepsis in mice with chronic alcohol ingestion. However, the efficacy of EGF in sepsis is blunted in the setting of chronic alcohol ingestion, as intestinal integrity and mortality in alcohol-fed mice given EGF improves animals to levels seen in water-fed mice given vehicle but does not approach levels seen in water-fed mice given EGF.

Intralesional epidermal growth factor therapy fordiabetic foot ulcers: an evaluation of 15 cases

Background/aim: Intralesional recombinant epidermal growth factor (EGF) is a new treatment approach for diabetic foot ulcer, approved in 2006. EGF therapy is given as an adjunct to the standard treatment regimen of antibiotics, surgery, and hyperbaric oxygen. EGF accelerates the healing of diabetic foot ulcers and reduces healing time. This single-center study was conducted to evaluate the outcomes of intralesional EGF therapy in patients with diabetic foot ulcers.Materials and methods: We present the data of the follow-up patients treated in our clinics. Fifteen patients with diabetic foot ulcers or infections, who had been followed up and treated in our clinics, were included in this retrospective study. All patients were administered intralesional injections of 75 μg of EGF after treatment for infection on their diabetic foot ulcers, three times a week on alternate days. The patients were monitored with respect to treatment response and side effects of EGF.Results: Thirteen patients (86.7%) developed new granulation tissue, 10 patients (66.7%) had complete wound closure, and three patients (20%) showed partial wound closure. No serious side effects requiring discontinuation of EGF therapy were observed. A total of twenty-one bacterial agents were isolated in thirteen patients, and no bacterial growth was observed in the tissue cultures of two patients. Pseudomonas aeruginosa was the most common isolated infectious agent in the tissue cultures (n: 6, 28%). Conclusion: Intralesional injection of EGF on top of the standard treatment regimen appears to be a useful adjuvant therapy option in selected patients.

EGF Accelerates Hematopoietic Stem Cell Regeneration Following 5-FU Chemotherapy Via G-CSF Receptor Signaling

Hematopoietic stem cells (HSCs) reside in specialized bone marrow microenvironments adjacent to endothelial cells (BM ECs). BM ECs regulate both HSC self-renewal and regeneration by expressing soluble growth factors such as epidermal growth factor (EGF). EGF accelerates HSC regeneration following ionizing radiation injury (Doan et al., Nat Med, 2013), though its role in HSC reconstitution after chemotherapy is not yet defined. At 24 hours following administration of 5-fluorouracil (5-FU), the expression of EGF receptor is increased 10-fold (p<0.0001) compared to untreated control mice within ckit+Sca-1+Lineage- (KSL) cells. EGFR expression is preferentially induced 6.8-fold in KSL cells compared to whole bone marrow cells after 5-FU (p=0.01). When C57Bl6 mice are treated with a single injection of 150 mg/kg 5-FU followed by daily injections of EGF for 4 days, they demonstrated preserved BM cellularity (p=0.0003), increased BM EC density (p=0.002), and contained higher levels of donor engraftment at 16-weeks post-secondary transplantation in competitive repopulating assays (mean 21.9% vs 52.2%, p=0.0005) compared to saline-treated control mice. Following a lethal dose of 5-FU, EGF-treated mice displayed 70% survival compared to 20% survival in saline-treated control mice (p=0.04). These results suggest that EGF signaling may accelerate both hematopoietic progenitor and stem cell reconstitution following myelosuppressive and lethal-dose chemotherapy.Since the pro-apoptotic gene Bax is increased 2.8-fold in BM lin- cells following 5-FU compared to cells from untreated mice (p<0.0001), we sought to determine whether chemo-protection of BM ECs via deletion of Baxwould accelerate HSC reconstitution. We employed a genetic mouse model with Cre recombinase to delete Bax specifically in VECadherin-expressing ECs (VECadherinCre;BaxFL/+ and VECadherinCre;BaxFL/FL mice). These mice displayed no differences in hematopoiesis at baseline. When C57Bl6 KSL cells are in non-contact co-cultures with BaxFL/+ BM ECs and treated with 5-fluorodeoxyuridine monophosphate (FdUMP) + EGF for 48 hours, they displayed both increased colony-forming cells (CFCs) and decreased annexin+ cells compared to control cultures (p=0.001 and p=0.03, respectively). Conversely, when C57Bl6 KSL cells are cultured with BaxFL/FL ECs and FdUMP + erlotinib, a tyrosine kinase inhibitor that neutralizes EGFR signaling, they displayed decreased CFCs and increased annexin+ cells compared to control cultures (p=0.001 and p=0.0003, respectively). These data suggest that chemo-protection of BM ECs by deletion of Bax in vivo results in accelerated hematopoietic recovery.Following 5-FU, EGF promoted cell cycling with increased Ki67+ cells and cells in interphase (mean 4.8% vs 16.1%, p=0.03). Moreover, EGF decreased annexin+ cells within the KSL population both in vitro following FdUMP (mean 26.3 % vs 17%, p=0.002) and in vivo following 5-FU (mean 21.5% vs 11.5%, p<0.0001). Concordant with these results, KSL cells treated with FdUMP + EGF displayed lower levels of double-strand DNA (dsDNA) breaks, measured by γH2AX, compared to control cultures (mean 39% vs 16%, p<0.0001). Since EGF can repair dsDNA breaks via non-homologous end joining recombination, we measured the levels of phosphorylation of DNA pk cs. Following 24 hours with FdUMP and 15 minutes with EGF, KSL cells displayed a 4.8-fold increase in phospho-DNA pk cs (T2647) compared to control cultures (p=0.04). Finally, we sought to determine whether EGF could accelerate HSC reconstitution via the granulocyte colony-stimulating factor (G-CSF) receptor. Following 5-FU + EGF, G-CSF-R expression is increased 3.6-fold in mRNA levels (p<0.0001) and by flow cytometric analysis (mean 23.9% vs 42.4%, p=0.003) compared to 5-FU-treated mice. These results suggest that EGF may be a potent HSC growth factor and may exert its effect at least in part via G-CSF receptor signaling. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Can Human Recombinant Epidermal Growth Factor Improve Ischemia and Induce Healing of Anastomosis in an Experimental Study in a Rabbit Model?

ABSTRACTPurpose: Anastomotic leaks following intestinal operations may cause devastating effects on patients. Ischemia may also occur at the intestinal walls in the presence of strangulations. In this study, we examined the effects of human recombinant (Hr)-epidermal growth factor (EGF) given at a single intramural dose into the intestinal walls and daily intraperitoneal cavity on ischemia and the healing process of anastomosis. Materials and Methods: Sixteen male New Zeland white rabbits were randomly divided into four groups (n = 4 in each group). In Group 1, two different segments of ileum were identified and, then, transected and the free ends were sutured each other. In the other groups, ischemia was induced by ligating the mesenteric vascular arcade. After the ischemic induction, Group 2 received intramural injections of %0.9 saline, Group 3 received intramural injections of a single dose of EGF, and Group 4 received intramural and intraperitoneal injections of EGF. Bursting pressures and tissue hydroxyproline levels were analyzed. Necrosis, fibroblastic activity, collagen deposition and neovascularization were also studied. Results: The mean levels of bursting pressures in Group 4 (148.6 ± 25.3 mmHg) were higher than Group 2 (70 ± 21.5 mmHg) (p = 0.001). The mean level of bursting pressures was not statistically significant between Group 1 (170.1 ± 35 mmHg) and Group 4 (p = 0.073). Hydroxyproline levels in Group 2 were lower than Groups 3 and 4. There was a statistically significant difference in the mucosal ischemia, mucosal healing and degree of adhesion, but not in the mural anastomotic healing among the groups. Conclusions: Intramural injection with daily intraperitoneal administration of low-dose EGF enhances the bursting pressure and collagen accumulation in ischemic anastomosis, improving many histological variables associated with ischemic intestinal anastomosis.

Biological defleecing: intravenous infusion of amino acid mixtures lacking lysine and methionine creates a weakened zone in the wool staple, which is amenable to mechanical wool harvesting

Conventional shearing of sheep is labour-intensive, expensive and presents significant occupational health and safety risks. The only alternative at present is based on injection of epidermal growth factor, which severs the fibre at the follicle level. This technology cannot be used in pregnant animals and requires application of a net to retain the severed fleece. An alternative is to create a weakened zone within the wool staple, which would be sufficiently strong to retain the fleece on the sheep while a protective covering regrows, but sufficiently weak as to allow painless and automated removal of the fleece. We demonstrate that this approach is possible using mixtures of amino acids lacking lysine and methionine. Initially we demonstrate the relationships between staple strength, a subjective ‘harvestability’ score and a subjective ‘pain’ score, using fleeces from animals treated with varying levels of cortisol to create a wide range of strengths of wool attachment. We assigned a score to the ease with which we could manually break the staples, and also to the animal’s response to breaking the staples still attached to the skin. The relationships between these variables indicated that a staple was considered harvestable and could be removed with minimal skin flinch response at a staple strength of ~10–13 N/kTex. Staples within this range were then produced by intravenous infusion of mixtures of amino acids lacking in lysine and methionine for a 5-day period. The weak point was uniformly created across the entire fleece and when a prototype roller-pin device was applied to the weakened wool, it uniformly broke the fleece of the three sheep tested. The mode of action of the amino acid treatment on wool growth was studied. There was no effect of unbalanced amino acids on the rate of follicle bulb cell division, the number of active wool follicles, or the length of the keratinisation zone in the wool follicle. Fibre diameter was reduced by ~4 microns by treatment, and intrinsic fibre strength (strength relative to cross-sectional area of the wool fibres), was reduced by ~50%. Results of these trials are encouraging but further work is required to develop a practical, on-farm method of altering systemic amino acid supply and to design an automated, high-throughput system of severing the weakened wool.

Regulation of basal cell plasticity by epidermal growth factor (EGF) and c‐Src in vivo in the mouse epididymis

Epididymal basal cells (BCs) sense the luminal environment by sending cell body projections that cross the tight‐junction barrier. BCs express the EGF receptor and its associated tyrosine kinase, c‐ Src, and we examined their role in their luminal sensing ability. BCs were visualized by in vivo multiphoton microscopy in our newly generated transgenic mice (KR5‐tdTomato), which express tdTomato exclusively in BCs. We found that BCs periodically elongate and retract their luminal‐reaching projections. Laser scanning confocal microscopy followed by 3D modeling showed that in vivo treatment with EGF (1 μM) or the EGFR inhibitor, Gefitinib (200 mg/kg/day), increased and decreased the number of luminal‐reaching BCs (labeled for keratin 5), respectively. Local EGF injection induced an increase in ERK1/2 phosphorylation. BCs in c‐Src knockout mice, which are infertile, exhibited no luminal‐reaching projections. We propose that EGF/EGFR/ERK1/2, together with c‐Src, are positive regulators of the luminal‐reaching property of BCs. A better understanding of the novel sensory function of BCs in the epididymis will help define their role in male fertility. This study is supported by NIH grant RO1DK085715.

Effect of nutrition, body condition and liveweight change on efficacy of biological wool harvesting with epidermal growth factor (Bioclip)

This study investigated the effect of nutrition on wool harvesting efficiency of a biological wool harvesting system (Bioclip) utilising epidermal growth factor (EGF) to induce shedding of the fleece. The experiment had nine groups, each representing a different growth path based on a 3 by 3 design with three levels of nutrition (low, medium and high) fed during two periods, specifically the pre-injection period (4-weeks leading up to EGF injection) and post-injection period (4 weeks between EGF injection and wool harvesting). Sheep weight and body condition score were measured at the start and end of each period. Wool harvesting efficiency, fleece weight and body wrinkle were assessed at wool harvesting. Continuous data were analysed using general linear models and linear regression. Bivariate categorical data were analysed using Chi-squared tests and odds ratios. Wool harvesting efficiency was reduced in sheep with greater skin wrinkle (P &lt; 0.001), poorer body condition (P &lt; 0.001) and poorer nutrition in both pre- and post-injection periods (P &lt; 0.001). Sheep that gained 1 kg bodyweight or 0.5 body condition score either pre- or post-injection had improved wool harvestability (P &lt; 0.05). Sheep that lost weight post-injection were 10.2 (95% confidence interval 4.0, 25.5) times and 4 times (2.4, 6.7) more likely to have very poor harvestability compared with sheep that gained or maintained weight respectively (P &lt; 0.001). Sheep with greater body wrinkle were 6.6 (4.1, 10.7) times more likely to have very poor harvestability than plain-bodied sheep (P &lt; 0.001). Nutrition that ensures modest weight gain during the pre- and post-injection periods can partially overcome poorer harvestability in wrinkly sheep.

Effects of epidermal growth factor and erythropoietin on Müller glial activation and phenotypic plasticity in the adult mammalian retina

Retinal Müller glia have received considerable attention with regard to their potential to function as quiescent retinal precursors. Various activation strategies induce characteristic features of retinal progenitor cells in Müller glia; however, these are often accompanied by hallmark features of reactive gliosis. We investigated the effects of an intravitreal injection of epidermal growth factor (EGF), a known mitogen, and erythropoietin (EPO) on activation and expression of developmental phenotypes within the adult retina. Using thymidine-analogue labeling as well as immunocytochemical and confocal analyses, we assayed the responses of retinal cells exposed to intravitreal administration of either EGF or EPO. We report that adult Müller glia incorporate bromodeoxyuridine (BrdU) and undergo a process of nuclear translocation to ectopic retinal layers following exposure to EGF. These cells survive within the retina for at least 23 days and express the developmental markers Pax6 and Chx10 as well as nestin and glial fibrillary acidic protein. Furthermore, we demonstrate that cotreatment with EGF and EPO suppresses aspects of EGF-induced glial reactivity, alters the retinal distribution of BrdU-positive nuclei, and serves to regulate the expression of developmental phenotypes seen in these cells. These data further our understanding of Müller cell responsiveness to intravitral, combinatorial growth factor treatments.

Blocking EGFR in the liver improves the tumor-to-liver uptake ratio of radiolabeled EGF

Overexpression of epidermal growth factor receptor (EGFR) in several types of malignant tumors correlates with disease progression. EGFR could, therefore, be an excellent candidate for targeted radionuclide diagnostics. However, the high natural expression of EGFR in the liver may be problematic. The aim of this study was to improve the tumor-to-liver ratio of radiolabeled epidermal growth factor (EGF) by blocking its uptake by the liver with a nonradiolabeled EGFR-targeting molecule in tumor-bearing mice. Intraperitoneally injected nonradiolabeled EGF was first evaluated as a blocking agent, preadministered at various time intervals before intravenous injection of (125)I-labeled EGF. The anti-EGFR Affibody molecule (Z(EGFR:955))(2) was then assessed as a blocking agent of (111)In-labeled EGF in a dual isotope study (50, 100, and 200 microg, preadministered 30 or 60 min before (111)In-EGF). The 30-min preadministration of nonradiolabeled EGF significantly decreased (125)I-EGF uptake in the liver, whereas uptake in the tumor remained unchanged. Furthermore, preadministration of only 50 microg (Z(EGFR:955))(2) as a blocking agent 30 min before the (111)In-EGF decreased the uptake of (111)In-EGF by the liver and increased its uptake by the tumor, thereby increasing the tumor-to-liver ratio sixfold. We conclude that the Affibody molecule (Z(EGFR:955))(2) shows promise as a blocking agent that could enhance the outcome of radionuclide-based EGFR-expressing tumor diagnostics and imaging.

Subcutaneous administration of epidermal growth factor: A true treatment option in case of postoperative liver failure?

Adequate hepatocyte regeneration is mandatory for successful recovery after liver resection. The role of epidermal growth factor (EGF), by subcutaneous injection as a simple route, has not been clearly elucidated yet. Wistar rats underwent 70 or 90% hepatectomy, respectively, and were treated with EGF at day 2 and 3 or served as non-EGF-treated controls. Postoperatively, proliferative parameters (weight of liver remnants, number of mitotic and Ki-67 positive cells, expression of cyclin D1 protein) were evaluated. After 90% hepatectomy, 5 day survival was recorded following EGF treatment using different dosages. A significant increase of hepatocellular proliferation was observed after 70% hepatectomy. However, survival following 90% hepatectomy was not as positively affected, irrespective of EGF dosage, with most animals dead before EGF application was completed. Subcutaneous EGF injection can augment postoperative liver regeneration, however, it might be used only as a prophylactic and not as a therapeutic drug in case of liver insufficiency.

In vivo glycyrrhizin accelerates liver regeneration and rapidly lowers serum transaminase activities in 70% partially hepatectomized rats

The in vivo effects of glycyrrhizin on restoration of liver mass and recovery of liver function were compared with those of epidermal growth factor (EGF), ibuprofen and dexamethasone in 70% partially hepatectomized rats. Hepatic regenerative activity was assessed based on the ratio of liver weight to 100 g body weight, and 5-bromo-2′-deoxyuridine (BrdU) incorporation into hepatocyte DNA in the remnant liver. Glycyrrhizin (50 mg/kg/day, i.p.)- or EGF (1.0 μg/kg/day, i.p.)-treated rats showed an approx. 1.4-fold increase in liver weight/100 g body weight ratio over saline-treated control rats on days 2 and 3 after 70% partial hepatectomy. BrdU labeling index in the remnant regenerating liver was significantly higher in glycyrrhizin- or EGF-treated rats when compared with saline-treated control rats on days 0.5 and 1. Ibuprofen (100 mg/kg/day, i.p.) and dexamethasone (0.1 mg/kg/day, i.p.) did not significantly increase either liver weight/100 g body weight ratio or BrdU labeling index. Serum activity of liver-related transaminases, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), elevated rapidly on day 1 and decreased to near pre-operative levels on day 5 after 70% partial hepatectomy in saline-treated control rats. Injection of glycyrrhizin or EGF significantly decreased the elevated serum ALT and AST activities on days 2 and 3 after hepatectomy when compared with saline-treated control rats. The transaminase-lowering effects of glycyrrhizin or EGF were smaller than those of ibuprofen and dexamethasone. These results demonstrate that injection of glycyrrhizin or EGF significantly enhances regeneration of liver mass and function, as well as recovery from the liver damage induced by surgical resection.

Juxtacrine Activation of Epidermal Growth Factor (EGF) Receptor by Membrane-anchored Heparin-binding EGF-like Growth Factor Protects Epithelial Cells from Anoikis While Maintaining an Epithelial Phenotype

Loss of cell-matrix adhesion is often associated with acute epithelial injury, suggesting that "anoikis" may be an important contributor to cell death. Resistance against anoikis is a key characteristic of transformed cells. When nontransformed epithelia are injured, activation of the epidermal growth factor (EGF) receptor (EGFR) by paracrine/autocrine release of soluble ligands can induce a prosurvival program, but there is generally evidence for concomitant dedifferentiation. The EGFR ligand, heparin-binding EGF-like growth factor (HB-EGF), is synthesized as a membrane-anchored precursor that can activate the EGFR via juxtacrine signaling or can be released and act as a soluble growth factor. In Madin-Darby canine kidney cells, expression of membrane-anchored HB-EGF increases cell-cell and cell-matrix adhesion. Therefore, these studies were designed to test the effects of juxtacrine HB-EGF signaling upon cell survival and epithelial integrity when cells are denied proper cell-matrix interactions. Cells expressing a noncleavable mutated form of membrane-anchored HB-EGF demonstrated increased survival from anoikis, formed larger cell aggregates, and maintained epithelial characteristics even following prolonged detachment from the substratum. Physical association between membrane-anchored HB-EGF and EGFR was observed. Signaling studies indicated synergistic effects of EGFR activation and phosphatidylinositol 3-kinase signaling to regulate apoptotic and survival pathways. In contrast, although administration of exogenous EGF partially suppressed anoikis in wild type cells, it also led to an increased expression of mesenchymal markers, suggesting dedifferentiation. Taken together, we propose a novel role for membrane-anchored HB-EGF in the cytoprotection of epithelial cells.

G.P.11.08 Intrathecal injection of epidermal growth factor and fibroblast growth factor 2 promotes proliferation of neural precursor cells in the spinal cords of mice with mutant human SOD1 gene

G.P.11.08 Intrathecal injection of epidermal growth factor and fibroblast growth factor 2 promotes proliferation of neural precursor cells in the spinal cords of mice with mutant human SOD1 gene