人胰腺癌细胞株放射敏感性的体外研究

目的通过体外实验探讨人胰腺癌细胞株的放射敏感性。方法培养人胰腺癌细胞株SW1990、Capan-1、AsPC-1、MIAPaCa-2、PANC-1、P3，应用集落形成实验测定胰腺癌细胞在6MVX线不同剂量照射后的存活分数，计算各株细胞的放射生物学参数。结果胰腺癌细胞株MIAPaCa-2对放射治疗最敏感，SF2为0．388，而Capan-1对放射治疗最不敏感，SF2为0．758，MIAPaCa-2与As-PC-1、AsPC-1与SW1990之间的放射敏感性无显著差异，其余各株胰腺癌细胞之间存在显著差异。结论不同胰腺癌细胞株的放射敏感性存在差异。     

诱导建立人胰腺癌耐放射细胞亚株的体外实验研究

目的 探索诱导并建立人胰腺癌耐放射细胞亚株的体外实验方法。方法 应用X射线对人胰腺癌细胞株SW1990、Capan-1、AsPC-1、MIAPaCa-2、PANC-1及P3进行梯度递增的诱导照射,随后观察其细胞形态学、细胞周期及放射敏感性的变化。结果 与亲本株相比,各株细胞受照射后形态均出现明显改变;耐放射株SW1990-R、ASPC—R、MIA-R、PAN—R及P3-R的G2／M均明显降低,而放射敏感性指标SF2升高9％～45％。结论 梯度增加照射剂量是可行的体外诱导建立人胰腺癌耐放射细胞亚株的方法。     

Effects of intraventricular infusion of vascular endothelial growth factor on cerebral blood flow,edema, and infarct volume

Summary.  Background: Therapeutic cerebral angiogenesis, utilizing angiogenic factors to enhance collateral vessel formation within the central nervous system, is a potential method for cerebral revascularization. A prior dose-response study determined that intracerebroventricular infusion of vascular endothelial growth factor (VEGF) increases vascular density with minimal associated brain edema at a concentration of 5 μg/ml. The purpose of this study was to assess effects of intracerebroventricular infusion of VEGF (5 μg/ml) on cerebral blood flow, infarct volume, and brain edema after ischemia.  Methods: Recombinant human VEGF₁₆₅ was infused into the right lateral ventricle of rats with an osmotic minipump at a rate of 1 μl/hr for 7 days. Control animals received vehicle only. Ischemia was produced by transient (2 hours) middle cerebral artery occlusion (MCAO). After MCAO, cerebral blood flow was determined with the indicator fractionation technique: infarct volume was assessed with 2,3,5-triphenlytetrazolium chloride staining, and brain edema was determined by measuring brain water content.  Findings: Cerebral blood flow was not significantly different in animals treated with VEGF compared to controls. There was a significant reduction in total infarct volume after temporary MCAO in VEGF-treated animals compared to controls (163±37 mm³ vs. 309±54 mm³, P<0.05). Brain water content after transient MCAO was also significantly reduced in VEGF-treated animals compared to controls (80.9±0.7% vs. 83.3±0.6%, P<0.05).  Interpretation: Intracerebroventricular infusion of VEGF₁₆₅ (5 μg/ml) decreases infarct volume and brain edema after temporary MCAO without a significant increase in cerebral blood flow. These results indicate that VEGF may have a direct neuroprotective effect in cerebral ischemia. Published online January 14, 2003 RID="*" ID="*"  This work was funded by a Pharmacia Upjohn Cerebrovascular Fellowship Award to Dr. Harrigan and an internal grant from the Department of Surgery, University of Michigan Health System.  Correspondence: M. R. Harrigan, M.D., Department of Neurosurgery, University of Michigan Health System, 1500 E. Medical Center Drive, Room 2128 Taubman Center, Campus Box 0338, Ann Arbor, MI 48109-0338.     

Gene therapy for myocardial angiogenesis

Objectives: We studied the therapeutic potential of ex vivo vascular endothelial growth factor (VEGF) gene-transduced H9c2 cell transplantation for myocardial neovascularization. Methods: The left ventricular free wall of adult Sprague-Dawley rats was cryodamaged. Two weeks after, naked plasmid encoding VEGF (VEGF1: 1μg/100 μl, VEGF5: 5μg/100μl), or VEGF transfected H9c2 myoblasts (0.5× 10⁶ cells/200 μl) were injected into the center of scar tissue. Four weeks after cryoinjury, scar diameters in the each group were measured. Neovascularization in the scar tissue was then quantified histologically. Results: Average scar tissue diameter 4 weeks after cryoinjury was as follows: TE (controls): 6.77±0.31 mm, H9c2: 5.08±0.43 mm; VEGF1: 5.90±0.20 mm; VEGF5: 4.50±0.24 mm. Scar tissue diameter was smaller in the 3 groups than in the control group (p<0.05). Capilary density by histological examination increased in naked plasmid injection groups (VEGF1: 1,209.9±305.3/mm²; VEGF5: 1,072.0±230.8/mm²) versus control (708.2±144.9/mm², p<0.05, p<0.05), and H9c2 cell transplantation group (1,379.4±391.6/mm²) versus controls (p<0.05). Conclusion: VEGF-transfected H9c2 myoblasts can transplantation group was markedly similar to direct myocardial injection in naked plasmid encoding VEGF groups.     

Urodynamic parameters in patients with slight and severe genuine stress incontinence: Is the stress profile useful?

This study evaluates the usefulness of the urethral pressure profile (UPP) parameters in assessing the severity of genuine stress incontinence (GSI). Functional length (FL), maximum urethral closure pressure (MUCP), pressure transmission ratio (PTR), residual area at stress (RAS), number of patients with incontinent spikes (IS), and distribution of IS on UPP were determined in supine and standing position for 54 patients (group I) with a 1 -hour pad test < 2 g and compared with the values of 63 patients (group 2) with a 1 -hour pad test > 2 g. The results were similar: FL (supine: 24 mm ± 6/26 mm ± 7 [P:0.2]; standing: 26 mm ± 8/24 mm ± 11 [P:0.5]); MUCP (supine: 51 cm H₂O ± 23/47 cm H₂O ± 20 [P:0.3]; standing: 45 cm H₂O ± 21/38 cm H₂O ± 18 [P:0.1]); and PTR (supine: 83% ± 27/84% ± 31 [P:0.9]; standing: 81% ± 25 and 88% ± 27 [P:0.3]). But the RAS was lower (supine: 502 mm² ± 497/246 mm² ± 268 [P < 0.009]; standing: 500 mm² ± 534/271 mm² ± 306 [P < 0.05]) in group 2. If the percentage of patients with IS was higher (supine: 57/93% [P < 0.001 ]; standing: 54/84% [P] < 0.011) in group 2, the distribution of IS over the entire FL demonstrated no differences between group 1 and 2. In conclusion, except for the RAS, standard UPP parameters cannot be considered determinant in assessing the severity of GSI. © 1994 Wiley-Liss, Inc.     

Evaluation of vascular endothelial growth factor blockade and matrix metalloproteinase inhibition as a combination therapy for experimental human pancreatic cancer

Blockade of vascular endothelial growth factor (VEGF) and inhibition of matrix metalloproteinases (MMP) are promising therapies for cancer. This study assessed the effects of a neutralizing anti-VEGF antibody (A4.6.1) and an MMP inhibitor (BB-94) on pancreatic cancer (PaCa) in vivo. Five million cells of two human PaCa cell lines (AsPC-1 and HPAF-2) were injected subcutaneously into nude mice; 1 mm³ fragments of the resulting tumors were implanted into the pancreas of other mice. Animals were randomized into a control group and three treatment groups: A4.6.1 (100 Μg intraperitoneally twice weekly); BB-94 (50 mg/kg every other day); and combination (A4.6.1 plus BB-94). Treatment was started after 3 days and continued for 14 weeks. Tumor volume, local and distant spread (score), and ascites were determined at autopsy. Microvessel density as a parameter of neoangiogenesis was analyzed in CD31-stained tumor sections. Both monotherapies reduced tumor volume (HPAF-2: −89% by A4.6.1 and −75% by BB-94; AsPC-1: −48% by A4.6.1 and −72% by BB-94), spread (HPAF-2: -−76% by A4.6.1 and -58% by BB-94; AsPC-1: −32% by A4.6.1 and −54% by BB-94), and microvessel density (HPAF-2: −75% by A4.6.1 and −30% by BB-94; AsPC-1: −59% by A4.6.1 and −30% by BB-94), resulting in a tendency toward increased survival (HPAF-2: 8 of 8 animals by A4.6.1 or BB-94 vs. 4 of 8; AsPC-1: 3 of 8 by A4.6.1, 4 of 8 by BB-94 vs. 1 of 8). Combination therapy yielded additional effects in the HPAF-2 group with regard to tumor volume (−95%) and development of ascites (0 of 8 vs. 2 of 8 by A4.6.1 or BB-94 vs. 5 of 8 control mice). Both VEGF blockade and MMP inhibition reduce primary tumor size, metastasis, and angiogenesis, thereby increasing survival in experimental pancreatic cancer. Combination treatment results in additive effects in moderately differentiated HPAF-2 tumors. Presented at the Forty-Third Annual Meeting of The Society for Surgery of the Alimentary Tract, San Francisco, California, May 19–22, 2002 (oral presentation). Supported by the R.S. Hirshberg Foundation and the Deutsche Forschungsgemeinschaft (grant HO 1843-1).     

Angiogenesis Inhibitor TNP-470 Can Suppress Hepatocellular Carcinoma Growth Without Retarding Liver Regeneration After Partial Hepatectomy

Purpose. We investigated the suppressive effect of the angiogenesis inhibitor TNP-470 on accelerated hepatocellular carcinoma (HCC) growth in the regenerating liver. Methods. After 70% partial hepatectomy (PH), AH-130 cells were injected into the portal vein of Donryu rats. A control group was given the vehicle only, and the treated group was given 10mg/kg TNP-470 subcutaneously every second day, from 24h after tumor implantation, seven times. On day 14, tumor growth was evaluated by the number of foci on the liver surface, liver weight, and the microvessel density of the tumor. Results. The number of foci was significantly less in the treated group (116.5 ± 103.1) than in the control group (319.3 ± 223.1) (P 0.05), as was microvessel density, which was 31.3 ± 14.0/mm² in the treated group and 61.2 ± 18.9/mm² in the control group (P 0.05). The liver tended to weigh less in the treated group (12.15 ± 1.28g) than in the control group (15.22 ± 5.35g). We also assessed whether TNP-470 retards liver regeneration. Seven days after 70% PH, the liver weight in the treated group was similar to that in the control group. Total bilirubin, serum glutamic oxaloacetic transaminase, and serum glutamic pyruvic transaminase were not higher in the treated group than in the control group. Conclusion. TNP-470 can suppress HCC growth without retarding liver regeneration after PH.     

Gene transfer of naked VEGF plasmid induces the formation of microvessels but not mature collaterals in ischaemic limb muscles

Summary   Background: Several studies have demonstrated increased numbers of angiographically detectable collaterals after vascular endothelial growth factor (VEGF) gene transfer. However, VEGF appears to be insufficient for stimulating the growth of mature blood vessels. Therefore, we decided to reinvestigate in what way the VEGF gene transfer to rabbit ischaemic muscle can restore blood flow impaired by femoral artery excision. Methods: Naked DNA, either control plasmid (pSVβgal) or pSG5-VEGF₁₆₅ (harbouring human VEGF cDNA), was injected into adductor magnus muscle. Results: Human VEGF₁₆₅ mRNA was detected in the ischaemic muscle injected with pSG5-VEGF₁₆₅, and human VEGF protein was present in the blood plasma of the same animals but not in rabbits treated with control plasmid. However, rabbit VEGF synthesis was also enhanced in ischaemic legs of both β-gal and VEGF-treated animals. In spite of the augmented generation of endogenous VEGF, the local blood flow decreased to 75±13.9 % (of flow before excision) after 28 days in pSVβgal injected animals, whereas it was preserved (97.3±15 %) in pSG5-VEGF₁₆₅ treated rabbits (P<0.02). Muscles of rabbits treated with pSG5-VEGF₁₆₅ showed a significantly higher number of microvessels in comparison to ischaemic muscles treated with pSVβgal (230±66 vessels/mm² vs 134±48;P<0.01), but angiographic analysis did not demonstrate significant differences in the number of collaterals between animals. Conclusions: The restoration of blood flow is most probably due to increased local angiogenesis and not to the formation of stable collateral vessels.      

Selective inhibition of endothelin receptor A as an anti-angiogenic and anti-proliferative strategy for human pancreatic cancer

Endothelin-1 (ET-1) plays a major role in tumor proliferation and angiogenesis of various types of cancer acting through endothelin receptors A and B (ETRA and ETRB). The aim of this study was to analyze theET-1/ETRsystem inhumanpancreatic cancer cell linesandto evaluate the effect of a selective endothelin A inhibitor in vitro and in vivo in an orthotopic mouse model. Three different human pancreatic cancer cell lines, MiaPaCa-2, AsPC-1, and Panc-1, were studied. We found that proliferation of human pancreatic carcinoma cells expressing ETRA was significantly reduced with a selective antagonist. Hypoxic conditions led to improved results compared to a normoxic environment (MiaPaCa-2: -53% vs. -18%; AsPC-1: -54% vs. -46%). Proliferation of ETRA negative Panc-1 cells was not decreased. In vivo, the selective ETRA inhibition resulted in reduced angiogenesis as measured by lower microvessel densities (MiaPaCa-2: -47%; AsPC-1: -55%). The blockade of ETRA decreased the volume (MiaPaCa-2: -87%; AsPC-1: -28%) and metastatic spread (MiaPaCa-2: -95.5%; AsPC-1: -27%) of receptorpositive tumors, thereby increasing survival in experimental pancreatic cancer. ETRA blockade did not show an effect on ETRA negative Panc-1 tumors. Therefore, targeting ETRA with a selective antagonist might provide a new approach to reducing proliferation and angiogenesis in human pancreatic cancer. Presented in part at the Forty-Fourth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Florida, May 18–21, 2003. This work was supported by the R.S. Hirshberg Foundation and the Deutsche Forschungsgemeinschaft (Grant HO 1843/2-1).     

First emerging evidence of the relationship between Onuf’s nucleus degeneration and reduced sperm number following spinal subarachnoid haemorrhage: Experimental study

Lumbosacral pathologies can lead to infertility. Onuf's nucleus changes in these pathologies may have a role in low sperm number. This study aims to investigate the relationship between Onuf's nucleus degeneration and sperm number following spinal subarachnoid haemorrhage. 22 rabbits were used. They were divided into three groups; five of them were used as the control (GI), five as the SHAM (GII) and twelve as the study groups (GIII). The study group received 0.7 ccs autologous blood into the spinal subarachnoid space at the T12-L1 level. After two weeks, all animals were decapitated, and S1–S3 laminectomy was done. Neurodegenerative changes of Onuf's nucleus, pudendal ganglia (S3) following two weeks after spinal SAH, were examined; sperm numbers were calculated. Degenerated neuron density of the Onuf's nucleus (n/mm³), the pudendal ganglia (S3) (n/mm³) and mean sperm numbers were calculated as 5 ± 2, 8 ± 3/mm³ and 98.345 ± 12.776/mm³ in the control (GI), 20 ± 5/mm³, 243 ± 66/mm³ and 91.841 ± 9.654/mm³ in the SHAM (GII), 143 ± 39/mm³, 2,350 ± 320/mm³ and 68.549 ± 5.540/mm³ in the study group (GIII). In conclusion, there were statistically significant differences between groups. Onuf's nucleus may be responsible for decreased sperm number following spinal SAH.     

Suramin Inhibits Not Only Tumor Growth and Metastasis but Also Angiogenesis in Experimental Pancreatic Cancer

Suramin inhibits the proliferation of several human tumors in vivo and in vitro. In this study, the effects of Suramin on proliferation and angiogenesis were investigated in human pancreatic cancer cell lines and in an orthotopic nude mouse model of human pancreatic cancer. The effects of Suramin on proliferation, viability, cell cycle, and apoptosis were studied in five human pancreatic cancer cell lines. Suramin inhibited the proliferation of pancreatic cancer cells in a dose-dependent manner and reduced viability at high concentrations. Cell cycle analysis revealed a decreased S-phase fraction in most cell lines, whereas the apoptotic fraction was not notably different. In vivo treatment with Suramin significantly reduced pancreatic tumor size (MiaPaCa-2, −74%; AsPC-1, −41%; and Capan-1, −49%) and metastatic spread (MiaPaCa-2, −79%; AsPC-1, −34%; and Capan, −38%). As a parameter for angiogenic activity, vascular endothelial growth factor (VEGF) secretion was measured, revealing reduced VEGF concentrations under Suramin treatment in both cell culture medium and ascites. Also, microvessel density quantified in primary tumors was reduced in animals treated with Suramin. Therefore, Suramin inhibits the proliferation of human pancreatic cancer in vitro and in vivo. The therapeutic effects seem to involve cell cycle kinetics and may be in part related to the antiangiogenic action of the drug. Supported by the R.S. Hirshberg Foundation and the Deutsche Forschungsgemeinschaft (Grant HO 1843/2-1 & 1843/3-1).     

Interaction of angiogenically stimulated intermediate CD163+ monocytes/macrophages with soft hydrophobic poly(n-butyl acrylate) networks with elastic moduli matched to that of human arteries

The cell population of peripheral blood monocytes/macrophages (MO) is heterogeneous: The majority of the MO are CD14⁺⁺ CD16^‐ and named “classical” (= MO1). Furthermore, two other subpopulations were described: CD14⁺⁺ CD16⁺ (“intermediate” = MO2) and CD14⁺ CD16⁺⁺ (“non‐classical” = MO3). It is reported that MO2 possess anti‐inflammatory properties and express the MO lineage marker CD163. On a hydrophilic neutrally charged acrylamide‐based hydrogel human intermediate (CD14⁺⁺ CD16⁺), angiogenically stimulated CD163⁺⁺ monocytes/macrophages (aMO2) maintained a proangiogenic and noninflammatory status for at least 14 days. Here, we explored whether this aMO2 subset adhered to hydrophobic poly(n‐butyl acrylate) networks (cPnBA) and also remained in its proangiogenic and noninflammatory status. Because substrate elasticity can impact adherence, morphology, and function of cells, cPnBAs with different Young's modulus (250 and 1100 kPa) were investigated, whereby their elasticity was tailored by variation of the cross‐linker content and matched to the elasticity of human arteries. The cPnBAs exhibited similar surface properties (e.g., surface roughness), which were maintained after ethylene oxide sterilization and exposure in serum‐free cell culture medium for 18 h at 37°C. aMO2 were seeded on cPnBA samples (1.7 × 10⁵ cells/1.33 cm²) in Dulbecco's modified Eagle medium (DMEM high glucose) supplemented with vascular endothelial growth factor 165 (VEGF‐A₁₆₅, 10 ng/mL) and fetal calf serum (10 vol%) for 3 and 72 h. On both polymeric samples (n = 3 each), the numbers of adherent cells per unit area were significantly higher (P < 0.01; cPnBA0250: 3 h 13 ± 5 cells/mm², 72 h 234 ± 106 cells/mm²; cPnBA1100: 3 h 14 ± 3 cells/mm², 72 h 198 ± 113 cells/mm²) compared to control cultures (glass, 3 h: 6 ± 3 cells/mm², 72 h: 130 ± 83 cells/mm²) and showed a typically spread morphology. The mRNA expression profile of the aMO2 was not influenced by the substrate elasticity. In the supernatant of aMO2 on cPnBA0250, significantly less VEGF‐A₁₆₅ product was found than expected based on the mRNA level measured (P < 0.01). Tests with recombinant VEGF‐A₁₆₅ then demonstrated that significantly more VEGF‐A₁₆₅ was adhered on cPnBA0250 than on cPnBA1100 (P < 0.01). Seeded on cPnBA, aMO2—unaffected by the elastic moduli of both substrates—seemed to remain in their subset status and secreted VEGF‐A₁₆₅ without release of proinflammatory cytokines. These in vitro results might indicate that this MO subset can be used as cellular delivery system for proangiogenic and noninflammatory mediators to support the endothelialization of cPnBA.     

A study on the vascular proliferation in tissues around the tumor in breast cancer

In order to study the vascular proliferation in human breast cancer, blood vessels were counted, per square millimeter, in the tissue immediately around tumors. Mastectomized specimens of 84 patients with breast cancer and specimens from 10 patients with benign mammary diseases were stained by hematoxylin eosin and, where required, by the avidin biotin peroxidase complex method for laminin staining. The vascular density around the breast cancer tissue was 20.35±8.40/mm², which was significantly higher than the value of 13.44±5.85/mm² for noncancerous mammary tissues (p<0.001) or the value of 12.65±4.12/mm² for benign mammary disease tissues (p<0.01). Among the breast cancers, noninvasive carcinoma had a higher vascular density (28.44±6.15/mm²) than invasive carcinoma (19.73±8.22/mm², p<0.02). According to the Japan Mammary Cancer Society Classification of invasive ductal carcinoma, vascularity was higher in the papillotubular type of cancer than in the solid-tubular or scirrhous types of cancer (p<0.02), although the papillotubular type had the lowest rate of nodal metastasis and vascular invasion as compared with the scirrhous and solid-tubular types. The vascular density around the tumors did not change in association with an increase in tumor size and it was suggested that blood vessels around a tumor would increase almost in proportion to the square of the tumor diameter.     

Vitamin D deficiency promotes growth of MCF-7 human breast cancer in a rodent model of osteosclerotic bone metastasis

IntroductionBreast cancer metastases to bone are common in advanced stage disease. We have recently demonstrated that vitamin D deficiency enhances breast cancer growth in an osteolytic mouse model of breast cancer metastasis. In this study, we examined the effects of vitamin D deficiency on tumor growth in an osteosclerotic model of intra-skeletal breast cancer in mice.MethodsThe effects of 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] on proliferation and apoptosis of MCF-7 breast cancer cells, and changes in the expression of genes within the vitamin D metabolic pathway (VDR, 1α- and 24-hydroxylase) were examined in vitro. MCF-7 breast cancer cells were injected intra-tibially into vitamin D deficient and vitamin D sufficient mice co-treated with and without osteoprotegerin (OPG). The development of tumor-related lesions was monitored via serial X-ray analysis. Tumor burden and indices of proliferation and apoptosis were determined by histology along with markers of bone turnover and serum intact PTH levels.ResultsIn vitro, MCF-7 cells expressed critical genes for vitamin D signalling and metabolism. Treatment with 1,25(OH)₂D₃ inhibited cell growth and proliferation, and increased apoptosis. In vivo, osteosclerotic lesions developed faster and were larger at endpoint in the tibiae of vitamin D deficient mice compared to vitamin D sufficient mice (1.49 ± 0.08 mm² versus 1.68 ± 0.15 mm², P < 0.05). Tumor area was increased by 55.8% in vitamin D deficient mice (0.81 ± 0.13 mm² versus 0.52 ± 0.11 mm² in vitamin D sufficient mice). OPG treatment inhibited bone turnover and caused an increase in PTH levels, while tumor burden was reduced by 90.4% in vitamin D sufficient mice and by 92.6% in vitamin D deficient mice. Tumor mitotic activity was increased in the tibiae of vitamin D deficient mice and apoptosis was decreased, consistent with faster growth.ConclusionVitamin D deficiency enhances both the growth of tumors and the tumor-induced osteosclerotic changes in the tibiae of mice following intratibial implantation of MCF-7 cells. Enhancement of tumor growth appears dependent on increased bone resorption rather than increased bone formation induced by these tumors.     

Systemic capsaicin inhibits neuronal activation in the brainstem during postoperative ileus in the mouse

Introduction Neuronal inhibitory reflex mechanisms contribute to postoperative ileus after abdominal surgery. During this condition, sensory neurons in the brainstem are activated. We aimed to determine the contribution of capsaicin-sensitive afferents to central vagal sensitivity in mice during postoperative ileus. Materials and methods Under enflurane anesthesia, C57BL/6 mice were laparotomized and the small bowel was manipulated to induce ileus or was left untouched as a sham-treatment group. A subgroup of ileus animals was pre-treated with Capsaicin (1 μm/kg, i.p.) 48 h before small bowel manipulation. The animals were killed 24 h later and the brainstem was removed for Fos immunohistochemistry, which was quantified in the nucleus of the solitary tract (nTS). Spontaneous jejunal motility was recorded in vitro. Leukocyte infiltration in the intestinal muscularis was studied by myeloperoxidase staining as an index of postoperative inflammation. Results There were 30±9 Fos-positive neurons counted in the nTS after ileus and 6±2 in sham controls (Bregma −7.70 mm, P=0.01). A reduction to 8±3 was observed after Capsaicin pre-treatment in ileus animals (P<0.05). Peak amplitudes of spontaneous jejunal motility were 2±0.3 cmH₂O during postoperative ileus, 3±0.6 cmH₂O after ileus with capsaicin pre-treatment, and 10±2 cmH₂O in control animals (N=6, both P<0.05). The number of leukocytes infiltrating the muscularis was 39±9/mm² during ileus and 1.8±1/mm² in controls (mean±SEM, P<0.01, N=6). After capsaicin, this number increased to 72±28/mm² in ileus animals (P<0.05 vs control animals, N=7). Conclusion The inhibition of capsaicin-sensitive vagal afferent pathways appears to boost rather than to attenuate the inflammatory response during postoperative ileus, while intestinal motility remained unchanged. This suggests a protective role of the capsaicin-sensitive afferent innervation for the inflammatory phase of postoperative ileus. Best of Forum Papers presented at the Annual Meeting of the German Society of Surgery, 2–5 May 2006, Berlin, Germany     

The inhibition of tumor cell adhesion on human mesothelial cells (HOMC) by phospholipids in vitro

Background and aims Intraperitoneal tumor cell adhesion to extracellular matrix and to mesothelial cells mediated by integrins is an important step in developing peritoneal carcinosis. In former animal studies, we could demonstrate that intraperitoneal treatment with a new phospholipid (PL) emulsion significantly reduces the amount of peritoneal carcinosis by adhesion prevention. This in vitro study tries to elucidate the influence of phospholipids on cells of the human gastric cancer cell line (NUGC-4) and the human rectal cancer cell line (HRT-18) adhering to mesothelial cells (HOMC) in a monolayer culture in vitro. Materials and methods HOMC cells were derived from omentum majus from patients undergoing elective abdominal surgery. Three passages of both cancer cell lines (NUGC-4 and HRT-18) were used. 1×10⁵/100 μl (HRT-18) or 1.2×10⁵/100 μl (NUGC-4) cells, according to forgoing dilution series, were pretreated with different concentrations of phospholipid emulsion (0.05, 0.1, 0.5, 0.75, 1% PL) stained with cell tracker chloromethyl-benzamidodialkylcarbocyanine (CM-DIL) and seeded into each well on the mesothelial monolayer. After 90 min, the number of adherent cells was counted by fluorescence microscopy at 530 and 620 nm. Additionally, flow cytometric analysis of integrin α3 and β1 expression on the tumor cell surface after treatment with phospholipids was completed. Results We found a dose dependent effect of phospholipids on both tumor cell lines causing a reduction of cell–cell adhesion. Already low concentrations of phospholipids (PL 0.5) had a significant influence. The mean cell count could be reduced from 234±12/mm² in controls to 124±41/mm² (PL 0.5; NUG-4) and from 295±49/mm² to 169±29/mm² (PL 0.5; HRT-18), respectively. Additionally, the integrin α3 and β1 expression on both cell lines could be reduced. Conclusion Our results within the scope of published data indicate that adhesion prevention is capable to reduce peritoneal carcinosis. Best of Forum Papers presented at the Annual Meeting of the German Society of Surgery, 2–5 May 2006, Berlin, Germany     

Effect of CO2 Pneumoperitoneum on Growth of Liver Micrometastases in a Rabbit Model

Little is known about the risk of metachronous liver metastases following laparoscopic resection for gastrointestinal malignancies. The effect of CO₂ pneumoperitoneum on the growth of established liver micrometastases was investigated in a rabbit model. Male Japanese white rabbits weighing 2.8 to 3.3 kg were randomized to three groups (n= 15 per group) 3 days following intraportal inoculation of a tumor suspension containing 5 × 10⁴ cells of VX₂ cancer. In the pneumoperitoneum group, insufflation with CO₂ was maintained at a pressure of 10 mmHg for 30 minutes. In the laparotomy group the abdominal cavity remained open through a 45 mm midline incision for 30 minutes; in the control group no treatment other than anesthesia was performed. Cancer nodules on the liver surface were compared among the three groups on day 17. There was no difference in the number of cancer nodules among the groups (p= 0.72). A significant difference in the total area of cancer nodules (mean ± SEM) was found only between the pneumoperitoneum group (696.0 ± 177.0 mm²) and the control group (247.2 ± 60.7 mm²) (p < 0.05). The frequency of cancer nodules larger than 3.0 mm in maximal diameter tended to be highest in the pneumoperitoneum group (p= 0.053). These results suggests that CO₂ pneumoperitoneum may promote the growth of established liver micrometastases in this animal model.