The early outcome of laparoscopic sigmoid and rectal resection for endometriosis.

AIM: Deeply infiltrating endometriosis (DIE) is the most severe form of endometriosis and may affect the rectum and sigmoid colon. The most effective treatment is segmental resection. We report our results of rectal and sigmoid resection for this. METHOD: The study comprises all patients who have had laparoscopic bowel resection for rectal or sigmoid endometriosis in the Päijät-Häme Central Hospital between 1 January 2004 and 31 May 2007. Patient demographics, operative details, complications and early postoperative recovery were prospectively collected and analysed. RESULTS: A total of 31 patients were treated using a multidisciplinary approach. The mean age was 33.6 years (range 21.7-48.6) and body mass index 24.2 (17-40). The mean operation time was 253.5 min (range 56-484). There were three sigmoid and 28 rectal resections and 80 concomitant gynaecological procedures. Conversion to open surgery was not required. A total of 23 (74.2%) patients recovered without complications. There were two major complications, anastomotic leakage and rectovaginal fistula. Minor complications included transient urinary retention (2), wound infection (1), pneumonia (1) and undefined fever (2). The mean time to full peroral diet was 3.8 days (range 3-7), to first flatus 2.6 days (1-4), to first bowel movement 3.5 days (2-6) and to discharge 5.7 days (4-13). CONCLUSION: Laparoscopic rectal and sigmoid resection for deep intestinal endometriosis is safe with few severe complications and rapid recovery. The long-term outcome on symptoms requires further study.

Adenoviral expression of vascular endothelial growth factor-C induces lymphangiogenesis in the skin.

The growth of blood and lymphatic vasculature is mediated in part by secreted polypeptides of the vascular endothelial growth factor (VEGF) family. The prototype VEGF binds VEGF receptor (VEGFR)-1 and VEGFR-2 and is angiogenic, whereas VEGF-C, which binds to VEGFR-2 and VEGFR-3, is either angiogenic or lymphangiogenic in different assays. We used an adenoviral gene transfer approach to compare the effects of these growth factors in adult mice. Recombinant adenoviruses encoding human VEGF-C or VEGF were injected subcutaneously into C57Bl6 mice or into the ears of nude mice. Immunohistochemical analysis showed that VEGF-C upregulated VEGFR-2 and VEGFR-3 expression and VEGF upregulated VEGFR-2 expression at 4 days after injection. After 2 weeks, histochemical and immunohistochemical analysis, including staining for the lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), the vascular endothelial marker platelet-endothelial cell adhesion molecule-1 (PECAM-1), and the proliferating cell nuclear antigen (PCNA) revealed that VEGF-C induced mainly lymphangiogenesis in contrast to VEGF, which induced only angiogenesis. These results have significant implications in the planning of gene therapy using these growth factors.

Expression of vascular endothelial growth factor receptor 3 in blood and lymphatic vessels of lung adenocarcinoma.

Vascular endothelial growth factor receptor 3 (VEGFR-3) has been proposed as a marker for lymphatic endothelial cells. This study investigated the expression of VEGFR-3 in the tumour vessels of lung adenocarcinoma and evaluated whether VEGFR-3 staining was useful for identifying lymphatic vessels within the tumour stroma. It also explored whether active growth of lymphatic vessels occurred in lung adenocarcinoma. Formalin-fixed, paraffin-embedded specimens obtained from 60 cases of lung adenocarcinoma, including five cases of pure bronchiolo-alveolar carcinoma (BAC) without stromal, vascular, and pleural invasion, were examined. No VEGFR-3-positive vessels were observed in pure BAC, but varying numbers of VEGFR-3-positive vessels were found in 39 of 55 (70.9%) invasive adenocarcinomas. A comparison of serial sections stained for VEGFR-3, CD31, and laminin-1 showed that most of the VEGFR-3-positive vessels appeared to be blood vessels (CD31-positive, laminin-1-positive), but some had the characteristics of lymphatic vessels (variable staining for CD31, little or no staining for laminin-1). VEGFR-3 staining highlighted lymphatic invasion by cancer cells; this invasion could not be detected by CD31 or haematoxylin and eosin (H&E) staining. Active growth of lymphatic vessels (as indicated by nuclear Ki-67 labelling of the endothelium) was observed in five tumours, four of which showed a high level of lymphatic invasion by cancer cells. It was concluded that VEGFR-3 immunostaining did not discriminate clearly between vascular and lymphatic endothelial cells, since expression of VEGFR-3 can be up-regulated in tumour blood vessels. However, VEGFR-3 staining combined with laminin-1 and CD31 staining would be useful for identifying lymphatic vessels and their invasion by tumour cells in a more objective way. Finally, proliferation of lymphatic endothelial cells may occur in association with lymphatic invasion by cancer cells.

Intravascular adenovirus-mediated VEGF-C gene transfer reduces neointima formation in balloon-denuded rabbit aorta.

BACKGROUND: Gene transfer to the vessel wall may provide new possibilities for the treatment of vascular disorders, such as postangioplasty restenosis. In this study, we analyzed the effects of adenovirus-mediated vascular endothelial growth factor (VEGF)-C gene transfer on neointima formation after endothelial denudation in rabbits. For comparison, a second group was treated with VEGF-A adenovirus and a third group with lacZ adenovirus. Clinical-grade adenoviruses were used for the study. METHODS AND RESULTS: Aortas of cholesterol-fed New Zealand White rabbits were balloon-denuded, and gene transfer was performed 3 days later. Animals were euthanized 2 and 4 weeks after the gene transfer, and intima/media ratio (I/M), histology, and cell proliferation were analyzed. Two weeks after the gene transfer, I/M in the lacZ-transfected control group was 0. 57+/-0.04. VEGF-C gene transfer reduced I/M to 0.38+/-0.02 (P:<0.05 versus lacZ group). I/M in VEGF-A-treated animals was 0.49+/-0.17 (P:=NS). The tendency that both VEGF groups had smaller I/M persisted at the 4-week time point, when the lacZ group had an I/M of 0.73+/-0.16, the VEGF-C group 0.44+/-0.14, and the VEGF-A group 0. 63+/-0.21 (P:=NS). Expression of VEGF receptors 1, 2, and 3 was detected in the vessel wall by immunocytochemistry and in situ hybridization. As an additional control, the effect of adenovirus on cell proliferation was analyzed by performing gene transfer to intact aorta without endothelial denudation. No differences were seen in smooth muscle cell proliferation or I/M between lacZ adenovirus and 0.9% saline-treated animals. CONCLUSIONS: Adenovirus-mediated VEGF-C gene transfer may be useful for the treatment of postangioplasty restenosis and vessel wall thickening after vascular manipulations.

Vascular endothelial growth factors VEGF-B and VEGF-C are expressed in human tumors.

The growth of solid tumors is dependent on angiogenesis, the formation of new blood vessels. Vascular endothelial growth factor (VEGF) is a secreted endothelial-cell-specific mitogen. We have recently characterized two novel endothelial growth factors with structural homology to VEGF and named them VEGF-B and VEGF-C. To further define the roles of VEGF-B and VEGF-C, we have studied their expression in a variety of human tumors, both malignant and benign. VEGF-B mRNA was detected in most of the tumor samples studied, and the mRNA and the protein product were localized to tumor cells. Endothelial cells of tumor vessels were also immunoreactive for VEGF-B, probably representing the binding sites of the VEGF-B polypeptide secreted by adjacent tumor cells. VEGF-C mRNA was detected in approximately one-half of the cancers analyzed. Via in situ hybridization, VEGF-C mRNA was also localized to tumor cells. All lymphomas studied contained low levels of VEGF-C mRNA, possibly reflecting the cell-specific pattern of expression of the VEGF-C gene in the corresponding normal cells. The expression of VEGF-C is associated with the development of lymphatic vessels, and VEGF-C could be an important factor regulating the mutual paracrine relationships between tumor cells and lymphatic endothelial cells. Furthermore, VEGF-C and VEGF-B can, similarly to VEGF, be involved in tumor angiogenesis.

Proinflammatory cytokines regulate expression of the lymphatic endothelial mitogen vascular endothelial growth factor-C.

Vascular endothelial growth factor (VEGF) is a prime regulator of normal and pathological angiogenesis. Three related endothelial cell growth factors, VEGF-B, VEGF-C, and VEGF-D were recently cloned. We have here studied the regulation of VEGF-C, a lymphatic endothelial growth factor, by angiogenic proinflammatory cytokines. Interleukin (IL)-1beta induced a concentration- and a time-dependent increase in VEGF-C, but not in VEGF-B, mRNA steady-state levels in human lung fibroblasts. The increase in VEGF-C mRNA levels was mainly due to increased transcription rather than elevated mRNA stability as detected by the nuclear run-on method and by following mRNA decay in the presence of an inhibitor of transcription, respectively. In contrast, angiopoietin-1 mRNA, encoding the ligand for the endothelial-specific Tek/Tie-2 receptor, was down-regulated by IL-1beta. Tumor necrosis factor-alpha and IL-1alpha also elevated VEGF-C mRNA steady-state levels, whereas the IL-1 receptor antagonist and dexamethasone inhibited the effect of IL-1beta. Experiments with cycloheximide indicated that the effect of IL-1beta was independent of protein synthesis. Hypoxia, which is an important inducer of VEGF expression, had no effect on VEGF-B or VEGF-C mRNA levels. IL-1beta and tumor necrosis factor-alpha also stimulated the production of VEGF-C protein by the fibroblasts. Cytokines and growth factors have previously been shown to down-regulate VEGF receptors in vascular endothelial cells. We found that the mRNA for the VEGF- and VEGF-C-binding VEGFR-2 (KDR/Flk-1) was stimulated by IL-1beta in human umbilical vein endothelial cells, whereas the mRNA levels of VEGFR-1 (Flt-1) and VEGFR-3 (Flt-4) were not altered. Our data suggest that in addition to VEGF, VEGF-C may also serve as an endothelial stimulus at sites of cytokine activation. In particular, these results raise the possibility that certain proinflammatory cytokines regulate the lymphatic vessels indirectly via VEGF-C.

Vascular endothelial growth factor-C: a growth factor for lymphatic and blood vascular endothelial cells.

The endothelial cells lining all vessels of the circulatory system have been recognized as key players in a variety of physiological and pathological settings. They act as regulators of vascular tone via the inducible nitric oxide system and in angiogenesis, the formation of blood vessels de novo. Aberrant regulation of endothelial cells contributes to tumor formation, atherosclerosis, and diseases such as psoriasis and rheumatoid arthritis. Among the most recently discovered growth factors for endothelial cells are newly isolated members of the platelet-derived growth factor/vascular endothelial growth factor (VEGF) family, VEGF-B, VEGF-C, and VEGF-D. VEGF-C is the ligand for the receptor tyrosine kinase VEGFR-3 (also known as Flt4), which is expressed predominantly in lymphatic endothelium of adult tissues, but a proteolytically processed form of VEGF-C can also activate VEGFR-2 of blood vessels. The lymphatic vessels have been known since the 17th century, but their specific roles in health and disease are still poorly understood. With the discovery of VEGF-C and its cognate receptor VEGFR-3, the regulation and functions of this important component of the circulatory system can be investigated.

Comparison of VEGF, VEGF-B, VEGF-C and Ang-1 mRNA regulation by serum, growth factors, oncoproteins and hypoxia.

The vascular endothelial growth factor (VEGF) family has recently been expanded by the isolation of two additional growth factors, VEGF-B and VEGF-C. Here we compare the regulation of steady-state levels of VEGF, VEGF-B and VEGF-C mRNAs in cultured cells by a variety of stimuli implicated in angiogenesis and endothelial cell physiology. Hypoxia, Ras oncoprotein and mutant p53 tumor suppressor, which are potent inducers of VEGF mRNA did not increase VEGF-B or VEGF-C mRNA levels. Serum and its component growth factors, platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) as well as transforming growth factor-beta (TGF-beta) and the tumor promoter phorbol myristate 12,13-acetate (PMA) stimulated VEGF-C, but not VEGF-B mRNA expression. Interestingly, these growth factors and hypoxia simultaneously downregulated the mRNA of another endothelial cell specific ligand, angiopoietin-1. Serum induction of VEGF-C mRNA occurred independently of protein synthesis; with an increase of the mRNA half-life from 3.5 h to 5.5-6 h, whereas VEGF-B mRNA was very stable (T 1/2>8 h). Our results reveal that the three VEGF genes are regulated in a strikingly different manner, suggesting that they serve distinct, although perhaps overlapping functions in vivo.