Fibroblast growth factor-2 (FGF-2) induces vascular endothelial growth factor (VEGF) expression in the endothelial cells of forming capillaries: an autocrine mechanism contributing to angiogenesis.

FGF-2 and VEGF are potent angiogenesis inducers in vivo and in vitro. Here we show that FGF-2 induces VEGF expression in vascular endothelial cells through autocrine and paracrine mechanisms. Addition of recombinant FGF-2 to cultured endothelial cells or upregulation of endogenous FGF-2 results in increased VEGF expression. Neutralizing monoclonal antibody to VEGF inhibits FGF-2-induced endothelial cell proliferation. Endogenous 18-kD FGF-2 production upregulates VEGF expression through extracellular interaction with cell membrane receptors; high-Mr FGF-2 (22-24-kD) acts via intracellular mechanism(s). During angiogenesis induced by FGF-2 in the mouse cornea, the endothelial cells of forming capillaries express VEGF mRNA and protein. Systemic administration of neutralizing VEGF antibody dramatically reduces FGF-2-induced angiogenesis. Because occasional fibroblasts or other cell types present in the corneal stroma show no significant expression of VEGF mRNA, these findings demonstrate that endothelial cell-derived VEGF is an important autocrine mediator of FGF-2-induced angiogenesis. Thus, angiogenesis in vivo can be modulated by a novel mechanism that involves the autocrine action of vascular endothelial cell-derived FGF-2 and VEGF.

Correlations of LTα and NQO1 gene polymorphisms with childhood asthma.

OBJECTIVE: To explore the correlation of the lymphotoxin alpha (LTα) and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 (NQO1) gene polymorphisms with childhood asthma. PATIENTS AND METHODS: A total of 102 asthma children (observation group) and 80 healthy children (control group) were enrolled. The information was collected via questionnaires and the polymorphisms of LTα rs2844484 and NQO1 rs2917666 were examined with the TaqMan-MGB probe. RESULTS: Observation group had higher constituent ratios of contact with animal furs, personal history of infection, personal history of allergy, familial infection history and familial allergic history than those of control group (p<0.05). However, there were no differences in age, sex, passive smoking, purchase of new furniture and mask wearing between the two groups (p>0.05). The frequency of LTα rs2844484 genotype AA was significantly higher than that of genotype AG and GG (p<0.01), and NQO1 rs2917666 genotype CC showed notably higher frequency than that of genotype CG and GG (p<0.05). The frequency of LTα rs2844484 A allele was significantly higher than that of G allele (p<0.01), while NQO1 rs2917666 C allele had remarkably higher frequency than G allele (p<0.05). The comparisons of the recessive and additive modes revealed differences between the two groups (p<0.05). However, we did not observe significant difference in dominant mode between the two groups (p>0.05). CONCLUSIONS: The risk factors for childhood asthma include the contact with animal furs, personal history of infection, personal history of allergy, familial infection history and familial allergic history. Polymorphisms of LTα and NQO1 genes are correlated with childhood asthma.

Antiangiogenic effects of camptothecin analogues 9-amino-20(S)-camptothecin, topotecan, and CPT-11 studied in the mouse cornea model.

Angiogenesis has been correlated with increased invasion and metastases in a variety of human neoplasms. Inadequate inhibition of the growth of tumor microvessels by anticancer agents may result in treatment failure, rated clinically as progressive or stable disease. We have investigated the antiangiogenic properties of three camptothecin analogues, 9-amino-20(S)-camptothecin, topotecan, and camptosar (CPT-11), currently under investigation in clinical settings. Angiogenesis was induced by basic fibroblast growth factor in the cornea of inbred Swiss-Webster mice, with the aim of exploring the suppression of neovascularization by the analogues injected into the mice daily over a period of 6 days. The dose range chosen is known to inhibit, in the mouse model, the growth of various human tumor xenografts or murine tumors. The statistical analysis evaluated the association between the area of neoangiogenesis and the dose of the drugs tested and correlated the effects with observed drug toxicity. It was established that, as the drug doses increased, the area of neovascularization decreased, appearing to approximate a negative exponential curve. 9-Amino-20(S)-camptothecin at 6.89 and 8.26 micromol/kg (2.5 and 3.0 mg/kg) and topotecan at 8.31 micromol/kg (3.5 mg/kg), both drugs being delivered over a 6-day period, had statistically significant reduction (47.2-72.5%) of neoangiogenesis and acceptable toxicity. At higher doses of the two analogues, toxic body-weight losses and deaths were observed. CPT-11 showed statistically significant reduction of neoangiogenesis at a dose of 359 micromol/kg (210 mg/kg) delivered over a 6-day course. Unlike camptothecin analogues, the nontoxic dose of vincristine did not induce a statistically significant inhibition of angiogenesis, and there was no dose-dependent escalation of antiangiogenic effects. The results indicate that camptothecins are most likely cytotoxic against two tumor compartments: in addition to tumor cells of epithelial origin, the drugs act against endothelial cells and prevent the growth of the tumor microvessels. We have hypothesized that treatment failure in some patients is due to incomplete or inadequate inhibition of the microvessel growth by camptothecins. Presumably, an intensive inhibition of the remaining tumor microvasculature in such patients could be achieved by combining a camptothecin with another antiangiogenic anticancer agent or with a highly selective angiogenic inhibitor exerting minimal dose-limiting toxicity. Such treatment by a camptothecin plus a less toxic inhibitor of angiogenesis can improve antitumor efficacy. To validate this concept, preclinical studies followed by clinical trials are planned.

U.S. experience with 749 laparoscopic adjustable gastric bands: intermediate outcomes.

BACKGROUND: Laparoscopic adjustable gastric band (LAGB) has consistently been shown to be a safe and effective treatment for morbid obesity, especially in Europe and Australia. Data from the U.S. regarding the LAGB has been insufficient. This study reveals our experience with 749 primary LAGB over a 3-year period in a U.S. university teaching hospital. METHODS: All data was prospectively collected and entered into an electronic registry. Characteristics evaluated for this study include preoperative age, BMI, gender, race, conversion rate, operative time, hospital stay, percent excess weight loss (%EWL) and postoperative complications. Annual esophagrams were performed RESULTS: From July 2001 through September 2004, 749 patients (531 females, 218 males) underwent LAGB for the treatment of morbid obesity. There were 630 Caucasians, 61 African-Americans, and 49 Latin Americans, with a mean age of 42.3 (range 18, 72 years) and mean BMI of 46.0 +/- 7.0 (range 35, 91.5 kg/m(2)). There was one conversion to open (0.1%). Median operative time and hospital stay were 60 minutes and 23 hours, respectively. The mean %EWL at 1 year, 2 years, and 3 years was 44.4 (+/-17.8), 51.8 (+/-20.9), and 52.0 (+/-19.6), respectively. There were no mortalities. Postoperative complications occurred in 12.8% of patients: 1.5% acute postoperative band obstruction, 0.9% wound infection, 2.9% gastric prolapse ("slip"), 2.0% concentric pouch dilatation (without slip), 0.8% aspiration pneumonia, 2.4% port/tubing problems, 0.3% severe esophageal dilatation/dysmotility (reversible), and 1.5% overall band removal. CONCLUSION: These American results substantiate the data from abroad that LAGB is a safe and effective treatment for morbid obesity.

Early results of laparoscopic biliopancreatic diversion with duodenal switch: a case series of 40 consecutive patients.

BACKGROUND: Biliopancreatic diversion with duodenal switch (BPD-DS) is an operation which provides one of the greatest maintained weight losses of any bariatric procedure. We looked at the safety and efficacy of laparoscopic BPD-DS for morbid obesity. METHODS: A 150-200 ml sleeve gastrectomy was created and anastomosed to the distal 250 cm of divided ileum. The median length of the common channel was 100 cm. All patients were prospectively followed up to 12 months. RESULTS: 40 consecutive patients underwent laparoscopic BPD-DS as a primary procedure for morbid obesity. Median patient body mass index (BMI) was 60 kg/m2 (range 42-85 kg/m2). Mean age was 43 +/- 1 years (+/- SEM), with 12 males and 28 females. One patient was converted to open laparotomy (2.5%). Median operative time was 210 +/- 9 minutes (range 110-360 minutes) with a significant correlation between BMI and operative time (p = 0.04). Median length of stay was 4 days (range 3-210 days). There was one 30-day mortality (2.5%). Major morbidities occurred in 6 patients (15%), including 1 anastomotic leak (2.5%), 1 venous thrombosis (2.5%), 4 staple-line hemorrhages (10%) and 1 subphrenic abscess (2.5%). Median follow-up at 6 months (range 1-12 months) resulted in 46% +/- 2% excess weight loss (EWL) and at 9 months 58% +/- 3% EWL. CONCLUSION: Laparoscopic BPD-DS is a complex, yet feasible, procedure resulting in effective weight loss with an acceptable morbidity. A BMI >65 was associated with increased morbidity and mortality. A long-term study is needed to confirm efficacy and proper patient selection.

Contribution of vasopressin to blood pressure regulation during hypovolemic hypotension in humans.

In animals subjected to hemorrhage, plasma arginine vasopressin concentrations increase to levels sufficient to cause vasoconstriction, thus attenuating the hypotensive response. The purpose of this study was to examine the contribution of vasopressin to blood pressure regulation during hypotension in humans. Hypotension was induced in twelve normal subjects by lower body negative pressure (LBNP) before and after intravenous administration of vasopressin V1 receptor antagonist. Before drug administration, LBNP reduced systolic blood pressure from 125 +/- 4 to 78 +/- 12 mmHg (P < 0.01) as vasopressin concentration increased from 2.9 +/- 0.6 to 17 +/- 6 pg/ml (P < 0.05). After administration of the vasopressin antagonist, LBNP reduced systolic blood pressure from 128 +/- 3 to 89 +/- 11 mmHg (P < 0.01). The hypotensive response to LBNP was not potentiated by inhibiting vasopressin's vasoconstrictive effects (P = NS). Thus hypotension causes marked increases in plasma vasopressin concentration. In contrast to findings in animal studies, however, vasopressin does not contribute to the maintenance of blood pressure during hypotension in humans.

Favorable early results of gastric banding for morbid obesity: the American experience.

BACKGROUND: In 2001 a new device for surgical weight loss was approved by the Food and Drug Administration (Lap-Band, Inamed Health). We describe initial results of laparoscopic gastric banding for morbid obesity in two American academic centers. METHODS: Prospective data was collected on consecutive morbidly obese patients undergoing laparoscopic adjustable gastric banding, and evaluated retrospectively. RESULTS: Four hundred forty-five consecutive patients underwent Lap-Band from May 2001 through December 2002. The 103 men and 341 women had an average age of 42.1 years (range 17-72 years) and an average body mass index (BMI) of 49.6 kg/m2 (range 35.2-92.2 kg/m2). One operation required conversion to laparotomy due to bleeding; the rest were completed laparoscopically. Mean length of stay was 1.1 days (range 1-10 days). There was one death. Additional complications included band slippage in 14 patients (3.1%), gastric obstruction without slip in 12 (2.7%), port migration in 2 (0.4%), tubing disconnections in 3 (0.7%), and port infection in 5 (1.1%). Two bands (0.4%) were removed due to intraabdominal abscess 2 months after placement. There was one band erosion (0.2%) and no clinically significant esophageal dilation. Ninety-nine patients have 1-year follow-up and have lost an average of 44.3% excess body weight. CONCLUSION: Laparoscopic gastric banding has much to offer the morbidly obese. We present data showing weight loss rivaling gastric bypass and acceptably low complications. These results parallel success with this device outside America.

Hand-assisted laparoscopic splenectomy for ruptured spleen.

Although the laparoscopic technique is an accepted method for elective splenectomy, it is controversial in the setting of trauma. A few reports have described laparoscopic splenorrhaphy for trauma, but none have performed laparoscopic splenectomy for splenic rupture. When the spleen is injured, vascular control and poor visibility due to bleeding present obstacles to laparoscopy. The development of the hand-assist device has helped surgeons make the transition from laparotomy to laparoscopy because of the advantages it provides, such as tactile sensation and immediate vascular control. We utilized these benefits of the hand-assist device to convert a laparoscopic operation to a hand-assisted laparoscopic operation and were thus able to avoid a laparotomy. We report a case in which the hand-assist device was used as an alternative to conversion during a laparoscopic splenectomy for ruptured spleen.

Limb vascular responsiveness to beta-adrenergic receptor stimulation in patients with congestive heart failure.

BACKGROUND: In patients with congestive heart failure, the chronotropic and inotropic responses to beta-adrenergic agonists are reduced. It is not known whether desensitization of peripheral beta-adrenoceptors accounts for impaired limb vasodilation in these patients. Accordingly, we studied 14 normal subjects and 13 age-matched patients with congestive heart failure. METHODS AND RESULTS: To distinguish vasodilation mediated by beta-adrenoceptors and adenylate cyclase from that mediated by stimulation of guanylate cyclase, each subject received intrabrachial artery infusions of isoproterenol (1-100 ng/min) and sodium nitroprusside (0.3-10 micrograms/min), respectively. Forearm blood flow was determined by venous occlusion plethysmography. Maximal vasodilative potential, determined during reactive hyperemia, was reduced in the patients with congestive heart failure. The maximal forearm blood flow response to isoproterenol was comparable in patients with heart failure and in normal subjects (8.0 +/- 1.1 versus 9.2 +/- 1.2 ml/100 ml of tissue/min, respectively, p = NS). Furthermore, the dose-response relation to isoproterenol was similar in both groups. Likewise, the forearm vasodilative response to sodium nitroprusside was preserved in the heart failure group. Plasma concentration of norepinephrine was higher in the patients with heart failure (436 +/- 34 versus 201 +/- 74 pg/ml, p less than 0.01). When both groups were considered, there was no correlation between norepinephrine levels and the maximal forearm blood flow response to isoproterenol (r = 0.10, p = NS). CONCLUSIONS: We conclude that beta-adrenoceptor desensitization does not occur in the limb vessels of patients with congestive heart failure.

Irsogladine maleate inhibits angiogenesis in wild-type and plasminogen activator-deficient mice.

BACKGROUND: The activation of the zymogen plasminogen to the serine protease plasmin by urokinase-type (uPA) and tissue-type (tPA) plasminogen activators (PA) is an important event in a variety of physiologic and pathophysiologic processes in mammals. Enhanced PA activity occurs during angiogenesis and has been correlated in vitro and in vivo with increased tumor aggressiveness and is an indicator of poor prognosis in a variety of tumors in humans. Preliminary studies suggest that the antiulcer drug irsogladine maleate (IM) diminishes PA activity in vitro and may inhibit angiogenesis in vivo. To define the precise mechanism of angiogenesis inhibition by IM in vivo, we tested the ability of IM to blunt angiogenesis in a mouse cornea neovascularization model performed in wild-type and PA-knockout mice. METHODS: Three days prior to pellet implantation, groups of C57Bl/6 wild-type, uPA-deficient (upA-/-), and tPA-deficient (tPA-/-) mice received IM (300 mg/kg), IM (500 mg/kg), or vehicle (0.5% carboxymethylcellulose) via oral gavage. After 3 days of treatment, hydron polymer-coated pellets of sucrose aluminum sulfate containing 100 ng of basic fibroblast growth factor (bFGF) were inserted into surgically created pockets in the cornea of each mouse. On postoperative day 6, the neovascularization of each cornea was evaluated by a blinded observer using slit lamp microscopy and photographed. Angiogenesis was quantified by calculating vascular area (mm2) +/- SEM using a modified formula for a half ellipse that incorporates calibrated vessel measurements [Vessel length (mm) x Clock hours x pi x 0.2]. RESULTS: IM treatment (300 and 500 mg/kg/day) resulted in a dose-dependent reduction of angiogenesis in wild-type mice by 21 and 45.3% (P < 0.02, P < 0.001), in tPA-deficient mice by 42.6 and 46% (P < 0.001, P < 0.001), and in uPA-deficient mice by 27.2 and 46% (P < 0.05, p < 0.001), respectively. No quantitative differences in neovascularization were observed in either treatment group between transgenic mouse strains. No toxicity was noted in any group. CONCLUSION: IM inhibits bFGF-induced angiogenesis in wild-type, tPA-knockout, and uPA-knockout mice. The observation that IM significantly diminishes angiogenesis in both PA-deficient mice and wild-type mice suggests that the mechanism of action of IM may be independent of plasminogen activation.