Adhesive small bowel obstruction after laparotomy during infancy.

BACKGROUND: Intra-abdominal adhesions can cause adhesive small bowel obstruction, chronic abdominal pain and female infertility. Reports on long-term outcomes following laparotomy during infancy are scarce. The aims of this study were to investigate the incidence of and risk factors for long-term adhesive small bowel obstruction and associated morbidity after laparotomy during infancy. METHODS: Infants who underwent laparotomy between 1976 and 2011 were identified. Data were extracted from medical records and a questionnaire was sent to the patients. RESULTS: Some 898 of 1185 eligible patients were included, with a median follow-up time of 14.7 (range 0.0-36.0) years. Median age at first laparotomy was 6 (range 1.0-365.0) days. There were 113 patients (12.6 per cent) with adhesive small bowel obstruction who underwent relaparotomy, 79 (69.9 per cent) occurring during the first 2 years after the initial laparotomy. The highest incidence of small bowel obstruction was found in patients with Hirschsprung's disease (19 of 65, 29 per cent), malrotation (13 of 45, 29 per cent), intestinal atresia (11 of 40, 28 per cent) and necrotizing enterocolitis (16 of 64, 25 per cent). Lengthy duration of surgery (hazard ratio (HR) 1.25, 95 per cent c.i. 1.07 to 1.45), stoma formation (HR 1.72, 1.15 to 2.56) and postoperative complications (HR 1.81, 1.12 to 2.92) were independent risk factors. Chronic abdominal pain was reported in 180 (24.0 per cent) of 750 patients, and 17 (13.8 per cent) of 123 women reported infertility. CONCLUSION: The incidence of adhesive small bowel obstruction after laparotomy in infants is high.

Locally increased concentrations of inflammatory cytokines in an experimental intraabdominal adhesion model.

BACKGROUND: Peritoneal adhesions may cause bowel obstruction, infertility, and pain. This study investigated cytokines, proteins and growth factors thought to promote formation of adhesions in an experimental intraabdominal adhesion model. METHODS: Male Sprague-Dawley rats were subjected to laparotomy, cecal abrasion, and construction of a small bowel anastomosis and examined at various time points after surgery. Concentrations of cytokines and growth factors in plasma and peritoneal fluid were analyzed using electrochemoluminescence and quantitative sandwich enzyme immunoassay technique. RESULTS: Concentrations of interleukin-6 (IL-6), interleukin-1beta (IL-1ß), and tumor necrosis factor alpha (TNF-α) increased in peritoneal fluid from 6h after incision. Plasma concentrations of IL-6 increased at 6h, but plasma concentrations of IL-1ß and TNF-α remained low. Peritoneal fluid concentrations of platelet-derived growth factor-BB (PDGF-BB), transforming growth factor beta1 (TGF-ß1), vascular endothelial growth factor (VEGF), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) were below detection levels at all time points. CONCLUSION: Early elevations of IL-6, IL-1ß, and TNF-α concentrations in peritoneal fluid correlated to adhesion formation in this rodent model. Our model is relevant and reproducible, suitable for intervention, and indicates that antiadhesion strategies should be early, local and not systemic.

Aedes aegypti salivary protein "aegyptin" co-inoculation modulates dengue virus infection in the vertebrate host.

Dengue virus (DENV) is transmitted in the saliva of the mosquito vector Aedes aegypti during blood meal acquisition. This saliva is composed of numerous proteins with the capacity to disrupt hemostasis or modulate the vertebrate immune response. One such protein, termed "aegyptin," is an allergen and inhibitor of clot formation, and has been found in decreased abundance in the saliva of DENV-infected mosquitoes. To examine the influence of aegyptin on DENV infection of the vertebrate, we inoculated IRF-3/7(-/- -/-) mice with DENV serotype 2 strain 1232 with and without co-inoculation of aegyptin. Mice that received aegyptin exhibited decreased DENV titers in inoculation sites and in circulation, as well as increased concentrations of GM-CSF, IFN-γ, IL-5, and IL-6, at 48 h post-inoculation when compared to mice that received inoculation of DENV alone. These and other data suggest that aegyptin impacts DENV perpetuation via elevated induction of the immune response.

Analysis of early dengue virus infection in mice as modulated by Aedes aegypti probing.

Dengue virus (DENV), the etiologic agent of dengue fever, is transmitted during probing of human skin by infected-mosquito bite. The expectorated viral inoculum also contains an assortment of mosquito salivary proteins that have been shown to modulate host hemostasis and innate immune responses. To examine the potential role of mosquito probing in DENV establishment within the vertebrate host, we inoculated mice intradermally with DENV serotype 2 strain 1232 at sites where Aedes aegypti had or had not probed immediately prior. We assayed these sites 3 h postinoculation with transcript arrays for the Toll-like receptor (TLR), RIG-I-like receptor, and NOD-like receptor signaling pathways of the innate immune system. We then chose TLR7, transcription factor p65 (RelA), gamma interferon (IFN-γ), and IFN-γ-inducible protein 10 (IP-10) from the arrays for further investigation and assayed these transcripts at 10 min, 3 h, and 6 h postinoculation. The transcripts for TLR7, RelA, IFN-γ, and IP-10 were significantly downregulated between 2- and 3-fold in the group subjected to mosquito probing relative to the virus-only inoculation group at 3 h postinoculation. A reduction in these transcripts could indicate reduced DENV recognition and antigen presentation and diminished inhibition of viral replication and spread. Further, mosquito probing resulted in viremia titers significantly higher than those in mice that did not receive probing. A. aegypti probing has a significant effect on the innate immune response to DENV infection and generates an early immune environment more permissive to the establishment of infection.

Synovial concentrations of the angiogenic peptides bFGF and VEGF do not discriminate rheumatoid arthritis from other forms of inflammatory arthritis.

OBJECTIVES: To investigate whether concentrations of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in aspirated synovial fluid can be used to distinguish rheumatoid arthritis from other forms of inflammatory arthritis. METHODS: bFGF and VEGF concentrations were measured in aspirated synovial fluid and serum samples from 66 patients with active arthritis (clinical diagnoses: rheumatoid arthritis (35 patients), psoriatic arthritis (9), reactive arthritis (11) and arthritis UNS (11)) utilizing commercial ELISA kits. RESULTS: In comparison with controls, elevated concentrations of VEGF were found in synovial fluid compared with in serum in all forms of arthritis. There were no significant differences in synovial fluid bFGF or VEGF concentrations between rheumatoid arthritis and the other forms of inflammatory arthritis. CONCLUSION: Both serum bFGF and VEGF concentrations were increased in patients with rheumatoid arthritis. Patients treated with steroids had lower synovial fluid bFGF concentrations. Synovial fluid levels of bFGF and VEGF were elevated but could not be used to distinguish rheumatoid arthritis from other forms of inflammatory arthritis.

Angiogenesis and angiogenic growth factors in Wilms tumor.

PURPOSE: Angiogenesis, that is new blood vessel formation, is a prerequisite for growth and metastasis of solid tumors. This study was undertaken to quantify tumor capillaries, investigate immunohistochemical expression and measure serum concentrations of angiogenic growth factors in patients with Wilms tumor. MATERIALS AND METHODS: The hospital records of 33 patients were reviewed and new slides were stained for the endothelial cell marker CD31. Capillaries were quantified in the most vascularized part of the tumor (hot spot) and in the whole slide. New slides were stained immunohistochemically for the angiogenic growth factors angiogenin, basic fibroblast growth factor (bFGF), transforming growth factor alpha, transforming growth factor beta1-3, tumor necrosis factor alpha and vascular endothelial growth factor (VEGF), and their immunoreactivity was quantified. Pretreatment serum samples from 14 patients and 56 healthy control children were analyzed using enzyme-linked immunosorbent assay kits for angiogenin, basic fibroblast growth factor, epidermal growth factor, hepatocyte growth factor, tumor necrosis factor alpha and VEGF. RESULTS: Logistic regression analysis and Kaplan-Meier estimates showed that quantifications based on the tumor hot spot had a significant impact on survival probability (p <0.05). The tumor hot spot counts were highest in the blastemal compartment. Levels of hepatocyte growth factor and VEGF in serum were 3 times higher than those in controls (p <0.01). CONCLUSIONS: Although the sample size is small in this study, the results imply that angiogenesis in Wilms tumor is driven by angiogenic growth factors, and that intratumoral capillary quantification and determinations of serum levels of angiogenic growth factors may be of clinical value.

Comparative evaluation of the antitumor activity of antiangiogenic proteins delivered by gene transfer.

Although the systemic administration of a number of different gene products has been shown to result in the inhibition of angiogenesis and tumor growth in different animal tumor models, the relative potency of those gene products has not been studied rigorously. To address this issue, recombinant adenoviruses encoding angiostatin, endostatin, and the ligand-binding ectodomains of the vascular endothelial growth factor receptors Flk1, Flt1, and neuropilin were generated and used to systemically deliver the different gene products in several different preexisting murine tumor models. Single i.v. injections of viruses encoding soluble forms of Flk1 or Flt1 resulted in approximately 80% inhibition of preexisting tumor growth in murine models involving both murine (Lewis lung carcinoma, T241 fibrosarcoma) and human (BxPC3 pancreatic carcinoma) tumors. In contrast, adenoviruses encoding angiostatin, endostatin, or neuropilin were significantly less effective. A strong correlation was observed between the effects of the different viruses on tumor growth and the activity of the viruses in the inhibition of corneal micropocket angiogenesis. These data underscore the need for comparative analyses of different therapeutic approaches that target tumor angiogenesis and provide a rationale for the selection of specific antiangiogenic gene products as lead candidates for use in gene therapy approaches aimed at the treatment of malignant and ocular disorders.

Oligomerization-dependent regulation of motility and morphogenesis by the collagen XVIII NC1/endostatin domain.

Collagen XVIII (c18) is a triple helical endothelial/epithelial basement membrane protein whose noncollagenous (NC)1 region trimerizes a COOH-terminal endostatin (ES) domain conserved in vertebrates, Caenorhabditis elegans and Drosophila. Here, the c18 NC1 domain functioned as a motility-inducing factor regulating the extracellular matrix (ECM)-dependent morphogenesis of endothelial and other cell types. This motogenic activity required ES domain oligomerization, was dependent on rac, cdc42, and mitogen-activated protein kinase, and exhibited functional distinction from the archetypal motogenic scatter factors hepatocyte growth factor and macrophage stimulatory protein. The motility-inducing and mitogen-activated protein kinase-stimulating activities of c18 NC1 were blocked by its physiologic cleavage product ES monomer, consistent with a proteolysis-dependent negative feedback mechanism. These data indicate that the collagen XVIII NC1 region encodes a motogen strictly requiring ES domain oligomerization and suggest a previously unsuspected mechanism for ECM regulation of motility and morphogenesis.

Angiogenesis and angioarchitecture of transplanted fetal porcine islet-like cell clusters.

Normoglycemic, athymic nude mice were implanted with 3 microl (approximately 250) fetal, porcine islet-like cell clusters under the renal capsule. The angioarchitecture of the transplanted islets was studied by microvascular corrosion casts 3 or 52 weeks after implantation. Arterioles were few, and observed mainly in the older age group. This is likely to be due to the fact that the arterioles were derived from intrarenal blood vessels, i.e., they were not visible on the graft surface. Within the grafts nests of capillaries, probably supplying a single islet-like cell clusters, could be seen in both groups. Numerous capillary sprouts were seen within the graft after 3 weeks, and to a slighter extent also after 1 year. Moreover, especially in grafts examined 3 weeks, but also 52 weeks, after transplantation, holes were observed in dilated capillary segments, suggesting that intussusceptive microvascular growth occurred in parallel with angiogenesis. A well-developed microvasculature could be observed 52 weeks after transplantation, whereas the number of capillaries in the implant was less pronounced 3 weeks postimplantation. The efferent venules were located peripherally in the islets and drained immediately into larger veins, derived from capsular veins clearly seen on the surface of the graft. It is concluded that xenotransplanted islet-like cell clusters develop an autonomous microcirculation by stimulating angiogenesis from surrounding blood vessels. Our findings suggest that single islet-like cell clusters remain morphologically intact after transplantation, and probably function as single endocrine units rather than forming a single homogenous endocrine tissue. Furthermore, it seems as if a continuous reorganization of the vasculature, with an associated angiogenesis, occurs throughout the observation period.

Pretreatment, ultrasound-guided cutting needle biopsies in childhood renal tumors.

BACKGROUND: The current International Society of Paediatric Oncology (SIOP)-10 protocol does not allow pretreatment histological classification of low-stage renal tumors in children for fear of needle tract recurrences. The aims of this retrospective study were to evaluate the safety, sensitivity, and specificity of ultrasound-guided cutting needle biopsies (UCNB) performed at our institution in pediatric patients with renal tumors. PROCEDURE: Of 28 pediatric patients presenting with a renal tumor between 1988 and 1996, 25 underwent biopsy with the Biopty biopsy instrument (needle diameter 1.2 mm). The preoperative biopsy and nephrectomy slides were reviewed by a SIOP reference pathologist. The patients' hospital records were reviewed and biopsy complications were noted. RESULTS: At review of the nephrectomy slides, the diagnoses were: Wilms tumor (16 patients), with anaplasia in one case, rhabdoid tumor (2 patients), neuroblastoma (2 patients), mesoblastic nephroma (2 patients), clear cell sarcoma (1 patient), malignant teratoma (1 patient), and renal cell carcinoma (1 patient). No needle tract recurrence or other major complication was observed. The only complication was local pain at the biopsy site, which occurred in 24% (6/25) of the cases. The sensitivity of UCNB was 76% (19/25); five biopsies did not yield diagnostic material and one was not concordant. All cases of Wilms tumor were correctly diagnosed by UCNB, but only 33% (3/9) of the other tumors. CONCLUSIONS: In all cases of Wilms tumor a correct diagnosis was made. The overall sensitivity was 76%. UCNB proved to be a safe procedure that was not associated with needle tract recurrence or other serious complications.

Inhibition of angiogenesis induces chromaffin differentiation and apoptosis in neuroblastoma.

Inhibition of angiogenesis has been shown to reduce tumor growth, metastasis, and tumor microvascular density in experimental models. To these effects we would now like to add induction of differentiation, based on biological analysis of xenografted human neuroblastoma (SH-SY5Y, WAG rnu/rnu) treated with the angiogenesis inhibitor TNP-470. Treatment with TNP-470 (10 mg/kg s.c., n = 15) reduced the tumor growth by 66% and stereological vascular parameters (Lv, Vv, Sv) by 36-45%. The tumor cell apoptotic fraction increased more than threefold, resulting in a decrease in viable tumor cells by 33%. In contrast, the mean vascular diameter (29 microm) and the mean tumor cell proliferative index (49%) were unaffected. TNP-470-treated tumors exhibited striking chromaffin differentiation of neuroblastoma cells, observed as increased expression of insulin-like growth factor II gene (+88%), tyrosine hydroxylase (+96%), chromogranin A, and cellular processes. Statistical analysis revealed an inverse correlation between differentiation and angiogenesis. It is suggested that by inhibiting angiogenesis, TNP-470 induces metabolic stress, resulting in chromaffin differentiation and apoptosis in neuroblastoma. Such agonal differentiation may be the link between angiostatic therapy and tumor cell apoptosis.

"No-touch" technique using saphenous vein harvested with its surrounding tissue for coronary artery bypass grafting maintains an intact endothelium.

Spasm and consequent dilation of the saphenous vein (SV) for coronary artery bypass grafting (CABG) can be avoided if the vein is harvested with its surrounding tissue. Morphologic techniques, including scanning and transmission electron microscopy, were used to compare endothelial cell integrity using three SV harvesting procedures: conventional (adventitial stripping of the vein, manual distention and storing in saline); intermediate (after adventitial stripping, the vein was left in situ, covered with a papaverine-soaked compress, and stored in heparinized blood); and "no-touch" (SV dissected with its surrounding tissue was left in situ, covered with a saline-soaked compress and stored in heparinized blood). Preservation of endothelial cell integrity was greater with the "no-touch" procedure than with the other methods. Since endothelial cell integrity of SV grafts may affect the patency rate, we conclude that the "no-touch" preparation should improve the results of CABG.

Phosphoinositide 3 kinase is critical for survival, mitogenesis and migration but not for differentiation of endothelial cells.

Angiogenesis involves endothelial cell invasion and migration into the surrounding tissue where cells differentiate, to form new lumen-containing vessels. We have investigated the role of phosphoinositide 3-kinase (PI3-kinase) in vascular endothelial growth factor (VEGF)- and fibroblast growth factor (FGF)-induced angiogenesis. Angiogenesis in vivo in chick embryos was inhibited by treatment with the PI3-kinase inhibitors wortmannin and LY294002. Stimulation of primary bovine capillary endothelial (BCE) cells with FGF-2, VEGF-A(165), or a combination of the two induced PI3-kinase activity in vitro and subsequent activation of the serine/threonine kinase Akt. The combination of FGF-2 and VEGF-A(165) led to an additive response. Activation of PI3-kinase was strictly required for FGF-2- and VEGF-A(165)-induced migration and DNA synthesis of BCE cells. Tubular morphogenesis was unaffected by treatment with wortmannin or LY294002, but survival of the tubular structures was dependent on PI3-kinase activity. VEGF-A(165) and FGF-2 induced increased stability of the tubular structures in a synergistic manner. These data indicate that PI3-kinase activity is required for migration, mitogenicity and survival but not for differentiation of endothelial cells during angiogenesis.

Reduced mucosal perianastomotic capillary density in rat small intestine with chronic radiation damage.

Anastomoses in an intestine with chronic radiation damage are prone to leakage, possibly due to a reduced blood supply induced by a reduced capillary bed. In an animal model, the numerical capillary density in the perianastomotic area was investigated in intestine with or without chronic radiation damage. A 2-cm segment of rat ileum received a single dose of 21 Gy. Twenty weeks later, when the chronic radiation-induced changes were established, an anastomosis was constructed in this segment and in a corresponding segment in control rats. In situ perfusion fixation of the intestine was done 4 or 7 days after construction of the anastomosis, sections of the intestine were removed surgically, the specimens were embedded in methacrylate plastic and sectioned at 2.5 microm, and capillaries were counted under a light microscope. The circumferential mucosal capillary density was lower in irradiated than in nonirradiated animals at both 4 and 7 days (P < 0.001 and P = 0.04, respectively). This reduction was greater in the mesenteric quadrant than in the other quadrants around the circumference. These results are indicative of a reduced capillary bed in the vicinity of anastomoses in intestine with chronic radiation damage, which might lead to an impeded blood supply and subsequent leakage.

[Angiogenesis inhibitors in advanced cancer. Many current clinical trials show promising results]. / Angiogeneshämmare vid avancerad cancer. Många påbörjade kliniska prövningar visar lovande resultat.

Tumour growth and metastasis are dependent on angiogenesis, the formation of new blood vessels. In experimental models, tumour regression can be induced by the administration of specific angiostatic agents. The inhibition of angiogenesis represents a new approach in cancer therapy. Specific inhibition of angiogenesis is not characterised by the typical dose-limiting toxicity of chemotherapy. By targeting the untransformed and genetically stable vascular endothelium, drug delivery is no problem, and angiostatic therapy is not associated with the development of drug resistance. However, the treatment has to be continued for months or years, and some angiostatic agents are known to interfere with fertility. Approximately thirty angiostatic agents are undergoing clinical trials, and another fifty agents preclinical testing. Since the clinical trials are performed on patients with advanced tumours intractable to conventional therapy, and as the test drugs are first generation angiostatic agents, their effect is measured in terms of delay in tumour progression or reduction in values for surrogate endpoints such as tumour markers. In this article, based on reports presented at a recent international conference on angiogenesis antagonists, a few angiostatic agents are reviewed with brief comments on their performance in early clinical trials, and some new and promising angiostatic strategies are outlined.

Tumor growth in a defined microcirculation.

The fate of human tumor cells deposited in rat uteri was investigated by light microscopy of histological sections, immunohistochemistry, and scanning electron microscopy of microvascular corrosion casts. The human colonic tumor cell line LS 174 T was used as graft since it can be detected by CEA immunohistochemistry, and spayed nude rats (PVG rnu/rnu) were used as hosts, subjected to different hormonal regimens (no exogenous hormones, medroxyprogesterone acetate, 17-beta-estradiol, or the last two regimens in combination). Intrauterine deposition of a suspension of 2 x 10(6) tumor cells resulted in tumor take in 72% (21/29) of the nude rats. Endometrial growth was verified in only three animals (14%, 3/21). Extraendometrial growth, however, was found in all animals with tumor take. These observations suggest that the endometrium is comparatively resistant to growth of xenografted human colonic tumor cells. The tumor microcirculation consisted of new vessels, giving morphological evidence that tumor growth is dependent on angiogenesis and not on invasion of preexisting vessels.

The angiogenesis inhibitor TNP-470 reduces the growth rate of human neuroblastoma in nude rats.

A new animal experimental model of human neuroblastoma is described. The model involves xenotransplantation of a poorly differentiated human neuroblastoma cell line (SH-SY5Y) to the subcutaneous tissue in the hind leg of nude rats (WAG mu/rnu). Injection of 20 million cells suspended in 0.2 mL of medium in each hind leg yielded an 89% tumor take (41/46) in 23 nude rats. Tumor take was evident after 2 wk. The tumors grew exponentially and reached a volume of 5.2 +/- 1.6 mL 4 wk after transplantation. The tumor cells retained their morphologic phenotype at the ultrastructural level after transplantation and were immunohistochemically positive for neuron-specific enolase and for chromogranins A and B. Subcutaneous injections of the angiogenesis inhibitor TNP-470 (10 mg/kg of body weight) every other day gave a treated/control quotient for mean tumor volume of 0.34 after 12 d of treatment. This implies that angiogenesis inhibition may be of value as a complement to chemotherapy in the treatment of human neuroblastoma. The presented animal experimental model is designed for investigations of the effects of chemotherapy, angiogenesis inhibitors, radiotherapy, and/or surgery on the growth rate of human neuroblastoma.