Ryusuke Muraoka

Association of vascular endothelial growth factor expression with tumor angiogenesis, survival and thymidine phosphorylase/ platelet-derived endothelial cell growth factor expression in human colorectal cancer

To examine the association of vascular endothelial growth factor (VEGF) expression with tumor angiogenesis, survival and thymidine phosphorylase/platelet-derived endothelial cell growth factor (dThdPase/PD-ECGF) expression in human colorectal cancer, immunohistochemical studies were performed on 136 cases of resected colorectal cancer specimens using antibodies for VEGF, KDR, CD34 and dThdPase/PD-ECGF. Fifty-nine cases (43%) were evaluated as positive for VEGF staining and 71 cases (52%) were evaluated as positive for dThdPase/PD-ECGF staining. The expression of VEGF correlated significantly with vessel counts and the expression of dThdPase/PD-ECGF (P = 0.01 and 0.01, respectively). Cox proportional hazards model analysis showed that vessel counts and VEGF expression were significant and independent prognostic factors, but that KDR expression was not.

Platelet-derived endothelial cell growth factor/thymidine phosphorylase expression correlated with tumor angiogenesis and macrophage infiltration in colorectal cancer

To clarify whether platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) expression in both tumor cells and stromal cells has independent or synergistic effects on tumor angiogenesis and progression and to explore a possible regulator for PD-ECGF/TP expression, immunohistochemical staining was conducted on 148 specimens of colorectal cancer. The microvessel count was significantly correlated with the extent of PD-ECGF/TP expression. Macrophage infiltration in tumors with positive TP was significantly higher than in tumors with negative TP (P < 0.001). The Cox model showed that PD-ECGF/TP expression was an independent prognostic factor, although the microvessel count had a stronger value in determining the patient prognosis.

EFFECT OF INTERMITTENT HEPATIC PEDICLE CLAMPING ON FREE RADICAL GENERATION IN THE RAT LIVER

BACKGROUNDnIntermittent hepatic pedicle clamping is thought to cause less hepatic reperfusion injury compared with continuous clamping. The mechanisms underlying this difference are unknown. We examined the relationship between intermittent ischemia/reperfusion and the production of free radicals using electron spin resonance spectrometry.nnnMETHODSnAlpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping (four cycles of 15-minute ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, free radical production in the liver was measured by an electron spin resonance spectrometer, and the level of hepatic injury was evaluated by measuring liver enzyme.nnnRESULTSnLonger periods of ischemia increased free radical production after reperfusion. There was no significant increase in free radical production or liver enzymes when the duration of ischemia was 15 minutes. Free radical production and liver damage were significantly less severe in intermittent pedicle clamping than in continuous clamping for 60 minutes, especially when the duration of the reperfusion between four cycles of ischemia was 15 minutes.nnnCONCLUSIONSnThese results indicate that intermittent pedicle clamping lessens free radical production when compared with continuous clamping, although many free radicals are produced.

Transmyocardial laser revascularization induced angiogenesis correlated with the expression of matrix metalloproteinases and platelet-derived endothelial cell growth factor

OBJECTIVEnTransmyocardial laser revascularization (TMLR) has been widely evaluated as a treatment for ischemic myocardium. However, its mechanism remains unclear. One mechanism is angiogenesis. This study examines the relationship between TMLR and angiogenesis from the viewpoint of matrix metalloproteinases and platelet-derived endothelial cell growth factor.nnnMETHODSnThe left anterior descending coronary artery (LAD) was ligated permanently in 12 beagle dogs. TMLR was accomplished in six of the 12 dogs using a carbon dioxide laser. No laser treatment was done in the six control dogs. Two weeks after the initial operation, dogs were euthanized and transmural samples (each of approximately 0.5 g) were cut from the center of the infarcted LAD territory, right ventricular wall, left circumflex artery perfuse area and interventricular septum except the LAD perfuse area. They were snap-frozen in liquid nitrogen for matrix metalloproteinases and platelet-derived endothelial cell growth factor activity analysis. Hematoxylin and eosin staining, double immunohistologic staining with anti-proliferating cell nuclear antigen and von Willebrand factor antibody, and immunohistologic staining with antibody against platelet-derived endothelial cell growth factor were performed for histologic studies. The activities of matrix metalloproteinases were examined by gelatin zymography. The activity of platelet-derived endothelial cell growth factor was examined by a spectrophotometric method.nnnRESULTSnThe channels were found to be infiltrated with granulation tissue and fibrosis. In the laser group, the active matrix metalloproteinase-2 and platelet-derived endothelial cell growth factor activity in the area of the left anterior descending coronary artery was significantly higher than in the control group (P<0.0001 and P=0.037, respectively). Within the channel remnants or close to these areas, the number of von Willebrand factor positive microvessels and proliferating cell nuclear antigen with correlating von Willebrand factor positive microvessels were significantly higher than in the control group (P=0.001 and P=0.0006, respectively). These increases in microvessels significantly correlated with the expression of matrix metalloproteinases and platelet-derived endothelial cell growth factor.nnnCONCLUSIONnBased on these findings it was concluded that transmyocardial laser revascularization induced angiogenesis correlated with the expression of active matrix metalloproteinases-2 and platelet-derived endothelial cell growth factor.

In vitro Growth Ability and Chemosensitivity of Gastric and Colorectal Cancer Cells Assessed with the Human Tumour Clonogenic Assay and the Thymidine Incorporation Assay

A human tumour cloning assay (HTCA) has been performed on 191 samples of gastric and 152 samples of colorectal cancers, and a thymidine incorporation assay (TIA) on 178 samples of gastric and 109 samples of colorectal cancers. The rate of evaluable assays was significantly higher in the TIA than in the HTCA (P less than 0.01). In terms of in vitro growth potential in the two assays, gastric cancer cells were less active than the colorectal cancer cells (P less than 0.05). In frequency of in vitro sensitivity to drugs, gastric cancer was more chemosensitive than colorectal cancer in both assays. The in vitro/in vivo correlations of high resistance-predictive ratios and low sensitivity-predictive ratios were similar in both assays. The results indicate that the TIA is more applicable than the HTCA to screening of active agents against fresh gastrointestinal cancers.

Hyperamylasemia and subclinical pancreatitis after cardiac surgery.

Hyperamylasemia after cardiac surgery is common but typically causes no clinical concern because it consists mainly of the salivary isoenzyme. In this study we evaluated the incidence, source, and time course of postoperative hyperamylasemia with special attention to the possibility of subclinical pancreatitis. In 88 patients prospectively tested for serum amylase and lipase concentrations, elastase 1 activity, and amylase isoenzyme characteristics, 57 (64%) showed hyperamylasemia during the early postoperative period. In most cases early hyperamylasemia was not of pancreatic origin, but two patients were diagnosed with subclinical pancreatitis. Among the last 23 patients, 5 of 10 patients with early hyperamylasemia exceeding 1000 IU/L showed late hyperamylasemia on the seventh postoperative day, when it represented mainly the pancreatic isoenzyme. Lipase concentrations and elastase 1 activities were elevated in these cases. Late hyperamylasemia following cardiac surgery may be of pancreatic origin and indicative of subclinical pancreatitis, even if early hyperamylasemia was of salivary origin.RésuméL’hyperamylasémie après chirurgie cardiaque est fréquente mais entraîne habituellement peu de soucis car il s’agit le plus souvent de l’isoenzyme salivaire. Dans cette étude, nous avons évalué l’incidence, la source et l’évolution dans le temps de l’hyperamylasémie postopératoire en tenant compte particulièrement de l’éventualité d’une pancréatite postopératoire infra-clinique. Chez 81 patients, analysés prospectivement pour l’amylase et la lipase sériques, l’activité en élastase l et les caractéristiques de l’isoenzyme, 57 (64%) avaient une hyperamylasémie en période postopératoire immédiate. Dans la plupart des cas, l’hyperamylasémie précoce n’était pas d’origine pancréatique, mais on a fait le diagnostic de pancréatite infraclinique chez deux patients. Parmi les 23 autres patients, 5 des 10 patients ayant une hyperamylasémie précoce au-dessus de 1000 IU/L avaient également une hyperamylasémie tardive au septième jour postopératoire, mais il s’agissait principalement d’enzyme d’origine pancréatique. Les concentrations en lipase et l’activité en élastase 1 étaient élevées dans ces cas. En conclusion, une hyperamylasémie tardive après chirurgie cardiaque peut être d’origine pancréatique et indique une pancréatite infra-clinique, même si l’hyperamylasémie précoce est d’origine salivaire.ResumenLa hiperamilasemia tras cirugia cardiaca es habitual pero no tiene repercusión clinica pues se trata sobre todo de la isoenzima salival. En este estudio evaluamos la frecuencia, el origen y la duración de la hiperamilasemia postoperatoria, prestando especial atención a la posible aparición de una pancreatitis subclinica. En 88 pacientes se determinó prospectivamente la concentración sérica de amilasa, lipasa, actividad de la elastasa l y las caracteristicas de la isoenzimas de la amilasa. 57 (64%) de los pacientes presentaron hiperamilasemia en el postoperatorio precoz. En la mayoria de los casos esta hiperamilasemia no reconocía una etiología pancreática, pero 2 pacientes fueron diagnosticados de pancreatitis subclínica. Entre los 23 últimos pacientes, en 5 de 10, que presentaron hiperamilasemia precoz superior a los 1,000 IU/L, se constató hiperamilasemia al séptimo día del postoperatorio, debido, sobre todo, a la isoenzima pancreática. La concentración de lipasa y la actividad de la elastasa l también estaban elevadas en estos casos. La hiperamilasemia tardía, tras cirugía cardiaca puede tener un origen pancreático reflejando una pancreatitis subclínica, incluso si la hiperamilasemia precoz reconoce un origen salival.

Invagination method with diagonal resection of the anal canal for cancer of the lower rectum

If the length of the remaining anal canal after surgery is not adequate, various problems with defecation can occur. With the purpose of preserving the anal canal as much as possible, a new attempt was made in patients with distal rectal cancer in whom the anal canal would be resected when the usual sphincter-sparing operation is applied. The novelty of this technique is that, when the invaginated technique of the Maunsell-Weir method is performed, the everted anal canal in the perineum is resected diagonally to permit preservation of a maximum length of the anal canal. Anastomoses with the diagonal rectal stump prohibit strictures, which frequently occur upon colo-anal anastomosis. Indications for this procedure include: the low region, at a distance less than 4 cm from the dentate line; less than T2 for mural stage, and less than one third the circumference for size. Four patients, in whom this technique was sequentially performed 3 years ago, were favorably reviewed according to various aspects such as tumor size, site, mural stage, lymph node metastasis, postoperative urination/defecation function, and stool soilage. We believe that this method should be the operation of choice in selected patients with low rectal cancer.