Vascular Endothelial Growth Factor Concentration in Brain of Rat Treated with Anaerobic Exercises

Anaerobic exercise is a high-intensity exercise that needs quick energy supplies obtained in a very short time. However, this exercise may result in tissue hypoxia which is characterized by the increase of HIF-1α concentration. The presence of HIF-1α will induce the secretion of VEGF and, eventually, trigger angiogenesis. Nevertheless, it is still unclear whether anaerobic exercise will also cause hypoxia in which this condition will increase the concentration of VEGF in brain tissues. The aim of this study was to find out the effect of anaerobic exercise frequency towards VEGF concentration of Wistar rat brain tissues. Brain tissues were taken from rats treated with anaerobic exercise using treadmill. This exercise was given in different frequencies; one time, three times, and seven times a week. The data collected were analyzed using independent t-test. The results of this study showed that anaerobic exercise done once a week could significantly increase VEGF concentration (p < 0.05) if compared with the one in control group (95.21 ± 31.99 v.s. 63.36 ± 11.01 pg/mL). Meanwhile, VEGF concentration of treatment groups given exercise three times a week (47.97 ± 10.68 pg/mL) and seven times a week (40.56 ± 13.98 pg/mL) showed a significant decrease if compared with that of control group (63.36 ± 11.01 pg/mL). Anaerobic exercise affected VEGF concentration as an indicator of angiogenesis in brain tissue of wistar rats

Effect on the canine Eck fistula liver of intraportal TGF‐β alone or with hepatic growth factors

Transforming growth factor‐β canceled the hepatocyte proliferation caused by transforming growth factor‐α when the two substances were mixed and administered through a disconnected central portal vein branch after creation of an Eck fistula. In contrast, transforming growth factor‐β had no antidotal action on the stimulatory effects of insulin or full test doses of insulinlike factor‐2, hepatocyte growth factor, epidermal growth factor or triiodothymanine. A minor antidotal effect on hepatic stimulatory substance activity could be detected, but only with hepatic stimulatory substance was given in doses smaller than those known to cause maximum stimulatory response. These results suggest a highly specific pharmacological and physiological interaction between transforming growth factor‐α and transforming growth factor‐α in the modulation of liver growth control. (HEPATOLOGY 1992;16:1267–1270.) Copyright © 1992 American Association for the Study of Liver Disease

Hepatocyte growth factor, a key tumor-promoting factor in the tumor microenvironment

The tumor microenvironment plays a key role in tumor development and progression. Stromal cells secrete growth factors, cytokines and extracellular matrix proteins which promote growth, survival and metastatic spread of cancer cells. Fibroblasts are the predominant constituent of the tumor stroma and Hepatocyte Growth Factor (HGF), the specific ligand for the tyrosine kinase receptor c-MET, is a major component of their secretome. Indeed, cancer-associated fibroblasts have been shown to promote growth, survival and migration of cancer cells in an HGF-dependent manner. Fibroblasts also confer resistance to anti-cancer therapy through HGF-induced epithelial mesenchymal transition (EMT) and activation of pro-survival signaling pathways such as ERK and AKT in tumor cells. Constitutive HGF/MET signaling in cancer cells is associated with increased tumor aggressiveness and predicts poor outcome in cancer patients. Due to its role in tumor progression and therapeutic resistance, both HGF and MET have emerged as valid therapeutic targets. Several inhibitors of MET and HGF are currently being tested in clinical trials. Preclinical data provide a strong indication that inhibitors of HGF/MET signaling overcome both primary and acquired resistance to EGFR, HER2, and BRAF targeting agents. These findings support the notion that co-targeting of cancer cells and stromal cells is required to prevent therapeutic resistance and to increase the overall survival rate of cancer patients. HGF dependence has emerged as a hallmark of therapeutic resistance, suggesting that inhibitors of biological activity of HGF should be included into therapeutic regimens of cancer patients

Synergistic growth factor microenvironments

Growth factors (GF) are remarkably powerful signalling molecules that orchestrate developmental biology. GFs are currently used in medjcal applications with limited success but it is clear that if their potential can be harnessed for biomedicine then they could underpin the discipline of regenerative medicine. However, while we understand that biology uses cell-secreted growth factors tethered to the ECM, biologists typically employ GFs in soluble format at high concentrations. When used in vivo, this causes off-target, unwanted effects, which severely limits their use. There is a vast amount of literature dealing with material systems that control the delivery of GFs. However, it was soon observed that GFs could be more effectively presented bound to surfaces from a solid-phase state rather than in soluble form, recapitulating the way the extracellular matrix (ECM) binds GFs. In parallel, evidence was found that within the ECM, GFs can actually work in cooperation with integrins and that this produced ehnaced GF signalling due to the crosstalk between both receptors. Recently this knowledge was used to engineer microenvironments that target simultaneous integrin and GF receptor engagement seeking to maximise GF effects in vitro (e.g. in terms of stem cell differentiation) but also tissue repair in vivo (e.g. bone regeneration and wound healing). This feature article introduces the concept of synergistic GF/integrin signalling and then introduces GF delivery systems that were key in the development of more advanced synergistic growth factor microenvironments

Growth Pattern and Condition Factor of Yellowfin Tuna Thunnus Albacares (Bonnaterre, 1788) in Eastern Indian Ocean

Tuna madidihang, Thunnus albacares (Bonnaterre,1788), merupakan salah satu spesies tuna ekonomis penting dan ter-sebar di perairan Indonesia, termasuk di WPP 572 (Samudra Hindia bagian barat Sumatera). Salah satu aspek penting yang berkaitan dengan upaya pemanfaatan berkelanjutan adalah pola pertumbuhan dan faktor kondisi. Penelitian ini bertujuan untuk mengkaji pola pertumbuhan dan faktor kondisi ikan madidihang di Samudra Hindia Bagian Timur. Jumlah ikan contoh yang diukur panjang dan bobotnya adalah 7.550 ekor yang mempunyai sebaran panjang 76-176 cm (rata-rata 129,03 cm) dan modus 150 cm. Hubungan panjang bobot ikan tersebut adalah W = 4x10-5L2,842 (R2 0,957). Secara umum pola pertumbuhan madidihang bersifat allometrik negatif yang berarti bahwa pertambahan panjang lebih cepat daripada bobotnya. Faktor kondisi relatif rata-rata madidihang adalah 0,975 dengan kecenderungan menurun seiring bertambahnya ukuran panjang. Faktor kondisi relatif tertinggi terjadi pada kelas panjang 80 cm sebesar 1,061 dan terendah terjadi pada kelas panjang 170 cm sebesar 0,918. Faktor kondisi relatif bulanan secara umum mengalami dua kali peningkatan dalam satu tahun yaitu dari bulan Februari hingga Juni dan dari Bulan Juli hingga Desember

Role of growth factors in the pathogenesis of tissue fibrosis in systemic sclerosis.

The most severe clinical and pathologic manifestations of systemic sclerosis (SSc) are the result of a fibrotic process characterized by the excessive and often progressive deposition of collagen and other connective tissue macromolecules in skin and numerous internal organs. The mechanisms involved in the initiation and progression of the remarkable fibrotic process in SSc remain largely unknown. Extensive recent studies have indicated that a variety of polypeptide growth factors play a crucial role in this process. The most commonly implicated growth factors include transforming growth factor beta (TGF-β), connective tissue growth factor (CTGF), platelet derived growth factor (PDGF), and vascular endothelial growth factor (VEGF). Here, the experimental evidence supporting the participation of various growth factors in the pathogenesis of the fibrotic process in SSc and the molecular mechanisms involved will be reviewed

Growth with a Fixed Factor

Consider an economy in which a fi…xed supply of unskilled labor can be combined with knowledge capital to produce consumption. The technology for accumulating knowledge capital is linear in knowledge capital. This leads to long-term growth if the production function for consumption goods is approximately Cobb-Douglas for large values of the stock of knowledge capital. The quality-ladder economy of Boldrin and Levine [2010] generates a menu of Leontief technologies with this feature. If the initial capital stock is low, there can be a long period of stagnation before unskilled wages start to grow, as in Lewis [1954]. A small open economy with a sufficiently low initial capital stock will run a trade surplus during its initial stages of development.economic growth, aggregate productivity