New measurement method for Sp factors (Phantom Scatter Factors) is presented. The theoretical development of the approach is disscused showing that Sp factors can be obtained from three measurements of ionnization in a blocked, reference field and open field. This method has been tested using 60Co gamma rays. The results were within 1% deviation between the theory and the experiment for the Sp facter. The new method does not need air measurement, and we could determine the Sp p factors with a small piece of block.
Gamma Rays ; Hepatocyte Growth Factor*

Total scatter factor (Scp), head scatter factor (Sc) and phantom scatter factor (Sp) are very important for accurate radiation therapy at stereotactic radiosurgery (SRS) with irregular field shape using micro-MLC and intensity modulated radiation therapy (IMRT) including many small field sizes. In this study we measured and compared Scp with reference ion chamber, pinpoint chamber and diode detector and adapted the resuls form diode detector. Head scatter factors for small field sizes were also measured with diode detector covered 1.5 cm-thick solid water build-up cap. Some errors like as electron contamination of 1~3% were included in the values of Sc but trend of total results of Sc was coincided with basic theory. Phantom scatter factors for small field sizes were calculated form Scp and Sc. The results of Sp were compared and were well-agreed with those of other authors.
Electrons ; Head ; Hepatocyte Growth Factor ; Radiosurgery ; Water

No abstract available.
Hepatocyte Growth Factor* ; Hepatocytes* ; Placenta* ; Pre-Eclampsia*

PURPOSE: Hepatocyte growth factor (HGF) is a modulator of epithelial cell proliferation and motility. In this study, we measured the level of HGF in sera and tumor extracts of gastric adenocarcinoma using an enzyme-linked immunoassay and evaluated its association with tumor progression. MATERIALS AND METHODS: The level of HGF in the sera of seventy-five patients with gastric adenocarcinoma and in the tumor extracts of forty-two tumors were examined in this study. The level of HGF was determined by an Immunis HGF EIA kit (Institute of Immunology). RESULTS: The mean level of HGF in the sera of patients was 0.26+/-0.19 ng/ml, which was significantly higher than in those of healthy controls (0.14+/-0.07 ng/ml, p<0.05); the levels of HGF in the sera of patients increased according to the progression of the stage of cancer (p<0.05). The mean level of HGF in tumor extracts was 8.22+/-9.27 microgram/g protein, which was significantly higher than in those of healthy controls (1.95+/-1.45 microgram/g protein, p<0.05); the levels of HGF in the tumor extracts were correlated significantly with the progression of the tumor stage (p<0.05). The mean level of HGF in the tumors of diffuse type was 11.28+/-11.74 microgram/g protein, which was significantly higher than in those of intestinal type (5.16+/-4.31 microgram/g protein, p<0.05). CONCLUSION: HGF may play an important role in the progression and differentiation of gastric adenocarcinoma.
Adenocarcinoma* ; Epithelial Cells ; Hepatocyte Growth Factor* ; Hepatocytes* ; Humans ; Immunoassay

BACKGROUND: Meningiomas show high recurrence rates even after curative tumor removal. The invasiveness of meningiomas may contribute to their high recurrence rates. Recently, c-MET and hepatocyte growth factor (HGF) have been reported to be involved in cancer invasion. METHODS: We examined the immunohistochemical expression of c-MET and HGF in 100 cases of patients with meningiomas who have undergone complete tumor removal. RESULTS: c-MET(-High) and HGF(-High) were found in 17% and 13% of meningiomas, respectively. Brain invasion was observed in 17.6% of c-MET(-High) meningiomas, but in only 2.4% of c-MET(-Low) meningiomas (p=.033). Bone/soft tissue invasion was observed in 23.5% of c-MET(-High) meningiomas and in 9.6% of c-MET(-Low) meningiomas (p=.119). HGF(-High) did not show statistical association with brain invasion or bone/soft tissue invasion. c-MET(-High) demonstrated shorter recurrence-free survival (RFS, 93.5+/-8.2 months vs 96.1+/-1.9 months); however, this difference was not statistically significant (p=.139). There was no association of HGF(-High) with RFS. CONCLUSIONS: This study demonstrates that c-MET(-High) is associated with brain invasion of meningiomas, and that c-MET expression may be a useful predictive marker for meningioma recurrence. Patients with invasive meningiomas with high expressions of c-MET may be good candidates for targeted therapy using c-MET inhibitors.
Brain ; Hepatocyte Growth Factor ; Humans ; Immunohistochemistry ; Meningioma* ; Neoplasm Invasiveness ; Proto-Oncogene Proteins c-met ; Recurrence

PURPOSE: The purpose of this study was to evaluate the prognostic significance of tumor angiogenesis and angiogenic factors such as hepatocyte growth factor (HGF) and c-met in renal cell carcinoma. MATERIALS AND METHODS: Immunohistochemical staining on HGF, c-met expression and angiogenesis was performed in 35 renal cell carcinoma tissues and 18 benign renal tissues. HGF and c-met were identified with specific corresponding antibodies. Cases were considered positive when HGF and c-met expression were seen in more than one third of cells. To evaluate the angiogenesis, the microvessels were determined by anti-CD31 immunohistochemistry. We compaired HGF, c-met and microvessel count with clinicopathologic characteristics such as stage, nuclear grade and histology in renal cell carcinoma. RESULTS: Among 35 patients with renal cell carcinoma, 16 patients (45.7%) showed positive stain for HGF and c-met. HGF, c-met overexpression and microvessel count were significantly correlated with tumor stage and nuclear grade of renal cell carcinoma (p<0.05), but not correlated with cell type of renal cell carcinoma. CONCLUSIONS: This results suggested that both HGF and c-met overexpression and angiogenesis measured by microvessels count could be significant prognostic indicators of renal cell carcinoma.
Angiogenesis Inducing Agents ; Antibodies ; Carcinoma, Renal Cell* ; Hepatocyte Growth Factor* ; Hepatocytes* ; Humans ; Immunohistochemistry ; Microvessels ; Prognosis

Hepatocyte growth factor (HGF) is a glycoprotein secreted from stromal fibroblasts which bind to the transmembrane Met receptor. This receptor is expressed from a variety of tumors, including gastric carcinomas. To look for a possible paracrine loop between gastric cancer cells and their surrounding fibroblasts in a gastric carcinoma, the effect of HGF on the morphology and expression of the cell- adhesion molecule E-cadherin was examined using fifty resected gastric carcinomas. The expression of Met and E-cadherin in primary gastric carcinoma was examined using immunohistochemical staining. The level of HGF in the tumor extracts was determined by using an Immunis HGF EIA kit (Institute of Immunology). The levels of HGF in the tumor extracts correlated significantly with the progression of the tumor stage (p<0.05). The mean level of HGF was significantly higher in the tumors of an undifferentiated type than in those of a differentiated type (p<0.05). Eighty-two percent (82%) of the tumors showed increased Met expression, but no significant correlation was found between Met expression and tumor progression or differentiation. Twenty-six (52%) tumors revealed a preserved E-cadherin expression similar to that of a normal gastric mucosa. Abnormal E-cadherin expression was found in twenty-four tumors (48%). There was a significant correlation between the degree of E-cadherin expression and the progression and differentiation of the tumor. The level of HGF in a tumor with cytoplasmic E-cadherin expression was significantly higher than that with membranous E-cadherin expression. In conclusion : we can conclude that HGF has the ability to modulate E-cadherin expression and induce intracellular translocation of E-cadherin in gastric carcinomas.
Cadherins* ; Cytoplasm ; Fibroblasts ; Gastric Mucosa ; Glycoproteins ; Hepatocyte Growth Factor ; Stomach Neoplasms

PURPOSE: To evaluate the correlation between hepatocyte growth factor (HGF) levels and the process of proliferative diabetic retinopathy. METHODS: Fourteen patients who had undergone vitrectomy were included in the study. Eight were diabetic patients with proliferative diabetic retinopathy (PDR) and six were non-diabetic controls. Vitreous and serum HGF was identified by Western blot analysis and then the level of HGF was measured with enzyme linked immunosorbent assay (ELISA). RESULTS: Western blot analysis confirmed 69kD polypeptide of HGF in vitreous and in serum of all 14 patients. Intravitreal concentrations of HGF was higher in PDR patients than in non-diabetic patients (p<0.01). However no significant differences was found between two groups regarding serum concentrations of HGF (p>0.05). While PDR patients did not show any correlation between the serum and the vitreous levels of HGF, control subjects showed a statistical significance (correlation coefficient=0.829; p=0.042). The ratio of serum HGF to vitreous HGF concentration was remarkably higher in PDR patients than in controls. CONCLUSIONS: Our result showed that increased concentration of HGF in vitreous seemed to be directly involved in the pathogenesis of PDR. Therefore vitreous level of HGF could be utilized as an indicator of the progression of PDR.
Blotting, Western ; Diabetic Retinopathy* ; Enzyme-Linked Immunosorbent Assay ; Hepatocyte Growth Factor* ; Hepatocytes* ; Humans ; Vitrectomy

BACKGROUNDMyopia is a common disorder and the incidence has increased yearly, but its pathogenesis remains unclear. The aim of this study was to investigate the possible role of hepatocyte growth factor (HGF) and its receptor c-Met in the development of lens-induced myopia in guinea pigs.

METHODSSixty one-week-old guinea pigs were chosen. The right eyes were treated with -10.0 diopters (D) lenses as the lens-induced myopia group; the left eyes remained untreated as the control group. Six weeks later, refractive status and axial length were determined by streak retinoscopy and A-scan ultrasonography, respectively. The guinea pigs were killed and both eyes collected. Morphological changes were observed by hematoxylin and eosin staining. The expression levels of HGF, c-Met, and matrix metalloproteinase 2 (MMP-2) mRNA and protein in the posterior sclera were analyzed by RT-PCR and Western blotting, respectively.

RESULTSThe lens-induced myopia group became myopic with a significant increase in axial length and a significant decrease in refraction. Compared with the control group, the posterior retina and sclera were thinner in the lens-induced myopia group. The expression levels of HGF and MMP-2 mRNA and protein and of phosphorylated c-Met protein were significantly higher in the posterior sclera of the lens-induced myopia group than in the control group (all P < 0.05). In the lens-induced myopia group, the expression level of MMP-2 in the posterior sclera positively correlated with the expression level of HGF (r = 0.902, P < 0.05) and phosphorylated c-Met (r = 0.885, P < 0.05).

CONCLUSIONHGF/c-Met might play a role in the development of lens-induced myopia in guinea pigs by upregulating the expression of MMP-2.

Animals ; Hepatocyte Growth Factor ; metabolism ; Humans ; Proto-Oncogene Proteins c-met ; Serine Endopeptidases