A case of megaloblastic anemia in the gibbon (Hylobates foolock).
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Biomedical subjects
Publications and source records attributed to Y Maede.
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A defect of the core protein of dermatan sulfate proteoglycan was suspected in a Holstein calf affected with a variant form of Ehlers-Danlos syndrome. The mutation was a guanine-to-adenine transition at nucleotide position 254, which resulted in a serine-to-asparagine substitution of the bovine proteoglycan core protein. This substitution occurred in the serine-glycine dipeptide repeat that was suspected to be the binding portion of dermatan sulfate. This point mutation in the genome was also detected by the use of restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) methods. The results of the RFLP and PCR indicated that the calf was a heterozygote of an abnormal gene and a normal gene of the core protein. The interpretation of these data revealed that the functional abnormality in cutaneous tissues of the calf was caused by an abnormal gene of the proteoglycan core protein, which induced a substitution of amino acid.
BACKGROUND: Vascular endothelial growth factor (VEGF) has been linked not only to angiogenic activity but also to thymidine phosphorylase (TP), rapid tumor growth, and inhibition of apoptotic cell death. Our purpose was to examine how VEGF expression affect these factors in cervical cancer at varying stages of progression. METHODS: VEGF expression, TP expression, the microvessel count (reflected by factor VIII-related antigen), and proliferating cell nuclear antigen (PCNA) were assessed immunohistochemically in 19 specimens of normal cervical epithelium, 35 of carcinoma in situ (CIS), 34 of microinvasive carcinoma (MIC), and 34 of invasive cervical squamous cell carcinoma (SCC). Apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. RESULTS: VEGF expression progressively increased along a continuum from normal epithelium to invasive SCC (P < 0.0001). VEGF expression significantly correlated with TP expression and PCNA index (P < 0.01 and P < 0.0001, respectively). In analyses within histological stages, VEGF expression significantly correlated with the PCNA index in CIS and MIC (P < 0.01 and P < 0.05, respectively), but not in invasive SCC. The PCNA index for combined analysis of VEGF and TP expression was similar to that for VEGF expression alone. VEGF expression tended to correlate with microvessel count, however, the difference was not significant (P = 0.09). No significant correlation was observed between VEGF expression and the apoptotic index. CONCLUSIONS: VEGF expression may stimulate tumor cell proliferation in the early stages of cervical cancer, and may be responsible for cervical tumorigenesis.
OBJECTIVE: The aim was first, to determine whether the expression of thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF) by epithelial ovarian cancer cells is correlated with the density of microvessels within the tumor and with ultrasonographic findings (B-mode classification and pulsed Doppler blood flow) and second, to speculate how these two angiogenesis factors participate in the tumorigenesis and tumor progression of epithelial ovarian cancer. METHODS: B-mode ultrasonography and color Doppler imaging and pulsed Doppler spectral analysis were used to scan patients with an overt ovarian mass immediately before laparotomy. Sections of malignant tumors were analyzed for the cellular expression of TP and VEGF and the intratumoral density of microvessels by immunohistochemistry using antibodies to TP, VEGF and Factor VIII related antigen, respectively. The main outcome measures were the histological classification of the tumor, the stage of the disease, whether or not the tumor cells were TP and VEGF positive or negative, the microvessel count and B-mode classification and the peak systolic velocity (PSV). RESULTS: Forty-four epithelial ovarian cancers were studied (6 of low malignant potential, 15 serous cystadenocarcinoma, 9 mucinous cystadenocarcinoma, 8 endometrioid adenocarcinoma, 4 clear cell carcinoma and 2 malignant Brenner tumor); 19 were Stage I, 6 Stage II, 15 Stage III and 4 Stage IV. Fourteen tumors (32%) were classified as TP positive and 21 (48%) as VEGF positive. The proportion of Stage I tumors that were TP positive (16%) was significantly lower (p = 0.022) than the corresponding value for Stages II-IV (44%), but the proportion with VEGF positive, the values for microvessel count and PSV were similar. Microvessel count did not significantly related to TP nor VEGF expression. The PSV was significantly higher in TP-positive tumors (p = 0.02) and VEGF-positive tumors (p = 0.006), respectively. There was a significant correlation between the microvessel count and the PSV (r = 0.34, p = 0.024). Moreover, specific B-mode classification significantly associated with disease stage and with TP expression, but not with VEGF expression. CONCLUSIONS: Angiogenesis is an early, critical step in the tumorigenesis of epithelial ovarian cancer, however, it does not provide significant information about tumor aggressiveness. When TP expression is superimposed upon the VEGF expression, the tumor might acquire the aggressive tumor phenotype.