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Insulin-like growth factor binding protein-4 (IGFBP-4) is an important member of the insulin-like growth factor (IGF) system. The IGFBP-4 has three domains of which the N-terminal sequence is important for the binding of IGF. It acts as a transport protein for IGF-I and IGF-II and modulates their biological effects. There is increasing evidence that IGFBP-4 inhibits IGF-induced cellular growth both in vitro and in vivo. IGFBP-4 can also mediate its actions through a mechanism independent of IGFs. IGFBP-4 level and expression in various tissues are influenced by IGFBP protease, nutrition, several growth factors and hormones. Overexpression of IGFBP-4 in transgenic animal models causes reduced growth of organs containing smooth muscle. Most cancers express IGFBP-4 at levels which correlate with their state of differentiation. However, the effects of IGFBP-4 on tumor growth are uncertain. In vitro studies have shown that overexpression of IGFBP-4 inhibit the growth of some colon cancer cells. Overexpression of IGFBP-4 in vivo has been reported to decrease the growth of prostate cancer. The effect of altered expression of IGFBP-4 in vivo in colon and other cancers needs to be explored as locally available IGFs appear to stimulate mitogenesis. Contents 1. Introduction 2. Structure and binding characteristics of IGFBP-4 3. Biological actions of IGFBP-4 4. Factors controlling IGFBP-4 expression 5.

Drains have been used in surgery for several years to remove body fluids thereby preventing the accumulation of serous fluid and improving wound healing. Drains may be classified as closed or open systems, and active or passive depending on their intended function. Closed vacuum drains apply negative suction in a sealed environment, producing apposition of tissues and thus promoting healing. Correct assessment of clinical indications might reduce unnecessary usage. This article will introduce the principles and practice of various types of drains and highlight the importance of understanding how surgical drains promote quality patient care.