Prediction of pathological response to preoperative chemotherapy for pancreatic ductal adenocarcinoma using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography.

AIM: To determine whether the pathological response to preoperative chemotherapy for pancreatic ductal adenocarcinoma (PDAC) can be predicted using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography (F-18 FDG-PET). MATERIALS AND METHODS: Twenty-eight patients with PDAC who underwent only neoadjuvant chemotherapy (NAC) before surgery were enrolled in the study. All patients had F-18 FDG-PET examinations before NAC. The resected specimen was pathologically evaluated according to the Classification of Pancreatic Carcinoma (7th edn). Patients were categorised into a non-response group and a response group based on the pathological findings. The non-response group (Grades 1a and 1b) showed ≤50% necrosis in the specimen, while the specimens of the response group (Grades 2-3) showed >50% necrosis. The maximum standardised uptake values (SUVmax) of the tumours on F-18 FDG-PET were measured. The mean values of SUVmax were compared between the two groups. The diagnostic performance of SUVmax in distinguishing the two groups was also evaluated using receiver operating characteristic analysis. RESULTS: The mean SUVmax of the response group was higher than that of the non-response group (9.00 ± 1.78 versus 4.26 ± 2.35; p<0.001). The optimal cut-off value of SUVmax was 9.28 for distinguishing the two groups. The sensitivity, specificity, and accuracy for the prediction in the response group were 80%, 95.7%, and 92.9%, respectively. CONCLUSIONS: SUVmax on F-18 FDG-PET may be useful as a biomarker to predict the pathological response to NAC in patients with PDAC.

Image quality and radiation dose of renal perfusion CT with low-dose contrast agent: a comparison with conventional CT using a 320-row system.

AIM: To compare perfusion computed tomography (CT) with reconstructed image from source data using low-dose contrast agent and conventional 320-row CT for the evaluation of renal tumours. MATERIALS AND METHODS: Twenty-eight patients underwent conventional CT (C-CT) and 26 patients underwent perfusion CT with low-dose (40 ml) contrast agent. Image noise, arterial visualisation, the sharpness of the corticomedullary junction (CMJ), and overall image quality were each assessed using a four-point scale. The tumour detection rate for lesions <4 cm (n=66) was also evaluated. Quantitative image parameters including image noise and the contrast-to-noise ratios (CNRs) of the renal artery and CMJ were measured. The volume CT dose index (CTDI), dose-length product (DLP), and size-specific dose estimate (SSDE) were also recorded. RESULTS: Although the image noise of perfusion CT was higher than that of C-CT and the overall image quality of perfusion CT was lower than that of C-CT, the arterial visualisation score of perfusion CT was significantly higher than that of C-CT. The CMJ sharpness scores of the two techniques were equivalent. Sensitivity and positive predictive values were also equivalent with respect to tumour detection. The CNRs of both the left and right renal arteries were significantly higher on perfusion CT than on C-CT. The CTDI, DLP, and SSDE of perfusion CT were significantly lower than those of C-CT. CONCLUSION: Perfusion CT using low-dose contrast agent preserved arterial visualisation and the tumour detection rate and achieved a low radiation dose despite image quality degradation and image noise.

Predictors of therapeutic effect of transarterial chemoembolisation using drug-eluting beads for hepatocellular carcinoma.

AIMS: To identify predictors of a therapeutic effect after transarterial chemoembolisation using drug-eluting beads (DEB-TACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Between January 2015 and July 2015, tumour variables and angiographic data were collected for 25 patients (49 target lesions) after they had undergone the DEB-TACE procedure for HCC. The therapeutic effect was evaluated according to the Response Evaluation Criteria in Cancer of the Liver at follow-up dynamic computed tomography (CT) performed within 1-4 months after the procedure. A p<0.05 was considered significant. RESULTS: On a target lesion basis, the objective response (TE3/4) rate was 63.3% (31 of 49). On univariate analysis, larger size (≥2 cm) was a predictor of an objective response (p=0.029). The tumour location of the medial (segment 4) or caudate (segment 1) lobe also indicated a poor therapeutic effect (TE1/2), but not at the level of significance (p=0.051). Multivariate analysis identified tumour size (odds ratio, 8.60; 95% confidence interval, 1.87-62.8) and tumour location (odds ratio, 12.2; 95% confidence interval, 2.12-129.8) as significant factors associated with a therapeutic effect. On a patient basis, 10 of 25 (40%) patients showed complete response/partial response. There were no significant differences between complete response/partial response and stable disease/progressive disease regarding age, gender, tumour markers, history of previous treatment, Child-Pugh class, T-stage, or Barcelona Clinic Liver Cancer Staging. CONCLUSION: A short-term therapeutic effect was associated with tumour size and location on a target lesion basis.

Balanced MR cholangiopancreatography with motion-sensitised driven-equilibrium (MSDE) preparation: feasibility of Gd-EOB-DTPA-enhanced biliary examination.

AIM: To evaluate the effectiveness of motion-sensitised driven-equilibrium (MSDE)-prepared balanced magnetic resonance cholangiopancreatography (MRCP) in a gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd-EOB-DTPA)-enhanced study compared to conventional T2-weighted MRCP. MATERIALS AND METHODS: Fifteen patients (seven male and eight female patients) prospectively underwent conventional three-dimensional turbo spin-echo T2-weighted MRCP and MSDE-balanced MRCP using a 1.5 T MRI system after hepatobiliary phase image acquisition. For quantitative evaluation, the contrast-to-noise ratio (CNR) of the common hepatic duct to liver tissue was calculated. For qualitative analysis, two radiologists evaluated the depiction of the biliary system and main pancreatic duct (MPD) using a scoring system. Signal suppression of the portal vein (PV) and hepatic vein (HV) on MSDE-balanced MRCP was also scored. RESULTS: MSDE-balanced MRCP showed significantly higher CNR than T2-weighted MRCP. For all biliary structures, the mean depiction scores of MSDE-balanced MRCP were significantly higher than those of T2-weighted MRCP, whereas the mean depiction score of MPD with MSDE-balanced MRCP was significantly lower than that of T2-weighted MRCP. Signal suppression of the PV and HV was thought to be clinically sufficient. CONCLUSIONS: MSDE-balanced MRCP more clearly depicted biliary structures compared with T2-weighted MRCP in a Gd-EOB-DTPA-enhanced study. This sequence may be utilised for routine MRCP on Gd-EOB-DTPA-enhanced MRI.

Heterogeneity of non-cancerous liver parenchyma on gadoxetic acid-enhanced MRI: an imaging biomarker for hepatocellular carcinoma development in chronic liver disease.

AIM: To clarify whether the heterogeneity of non-cancerous liver parenchyma (NLP) in the hepatobiliary phase on gadoxetic acid enhanced magnetic resonance imaging (MRI) is correlated with hepatocellular carcinoma (HCC) development. MATERIALS AND METHODS: Institutional review board approval was obtained, and the requirements for informed consent were waived for this retrospective study. The imaging characteristics of 84 patients with chronic liver disease who underwent gadoxetic acid-enhanced 3T MRI between January 2013 and October 2014 were examined retrospectively. For the evaluation of the heterogeneity of the intensity in the hepatobiliary phase, the largest possible region of interest was placed on the NLP, and the skewness and kurtosis were calculated using ImageJ software. Skewness is the degree of asymmetry of a histogram, and kurtosis is a measure of the peak. Based on the median values of kurtosis and skewness, the patients were classified into four categories and the categories were compared between the 49 patients with HCC (HCC group) and the 35 patients without HCC (non-HCC group). RESULTS: Kurtosis was significantly higher in the HCC group compared to the non-HCC group (1.19±1.15 versus 0.43±0.83; p=0.0006). Skewness was significantly lower in the HCC group than in the non-HCC group (1.19±1.15 versus 0.43±0.83; p=0.0152). In a multivariate logistic analysis, the category showing lower-than-the-median (-0.1185) skewness and higher-than-the-median (0.547) kurtosis was significantly and independently associated with HCC development (p=0.0031). CONCLUSION: The heterogeneity of NLP in the hepatobiliary phase on gadoxetic acid enhanced MRI may reflect the development of HCC.

Fatty change in moderately and poorly differentiated hepatocellular carcinoma on MRI: a possible mechanism related to decreased arterial flow.

AIM: To clarify the frequency of fatty change in moderately and poorly differentiated hepatocellular carcinomas (mHCCs and pHCCs) and its relationship to arterial blood flow. MATERIALS AND METHODS: One hundred and thirty-six surgically resected HCC lesions were studied. All patients had undergone dynamic magnetic resonance imaging (MRI) with chemical-shift-encoded water-fat imaging (CSI). The presence of fat was identified by a signal drop-off on CSI and confirmed at pathology. Lesions were classified into four groups in the arterial phase; G1, hypointense; G2, isointense; G3, slightly and heterogeneously hyperintense; G4, markedly and homogeneously hyperintense. The number of cumulative arteries (CAs) in the tumours in the pathology examination were counted. RESULTS: A fat component was observed significantly more frequently in the pHCCs (13/21; 61.9%) compared to the mHCCs (32/101; 31.7%; p=0.013). The numbers of lesions in each group were as follows: (G1, G2, G3, G4) = (18, 9, 23, 4) in the HCCs with fat; (1, 6, 24, 51) in the HCCs without fat (p<0.001); (5, 5, 18, 4) in the mHCCs with fat; (0, 3, 19, 47) in the mHCCs without fat (p<0.001); (11, 0, 2, 0) in the pHCCs with fat; (0, 2, 3, 3) in the pHCCs without fat (p=0.001). The number of CAs in the fat-containing HCCs (5.5±2.9) was significantly lower than that in the HCCs without fat (10.8±5.3; p<0.001). CONCLUSION: A fat component was more commonly observed in the pHCCs than in the mHCCs. The present results showed a possible mechanism of fatty change in mHCCs and pHCCs in relation to decreased arterial blood supply.

Correlation between portal vein anatomy and bile duct variation in 407 living liver donors.

Our aim was to determine whether variant bile duct (BD) anatomy is associated with portal vein (PV) and/or hepatic artery (HA) anatomy. We examined the associations between BD anatomy and PV and/or HA anatomy in 407 living donor transplantation donors. We also examined whether the right posterior BD (RPBD) course was associated with the PV and/or HA anatomy. Variant PV, HA and BD anatomies were found in 11%, 25% and 25%, respectively, of 407 donors enrolled in this study. The presence of a variant BD was more frequently associated with a variant PV than with a normal PV (61% vs. 20%, p < 0.0001). By contrast, the presence of a variant HA was not associated with a variant BD. A supraportal RPBD was found in 357 donors (88%) and an infraportal RPBD was found in 50 donors (12%). An infraportal RPBD was significantly more common in donors with a variant PV than in donors with a normal PV (30% vs. 10%, p = 0.0004). Variant PV, but not variant HA, anatomies were frequently associated with variant BD anatomy. Additionally, an infraportal RPBD was more common in donors with a variant PV than in donors with a normal PV.

Functional assessment of the liver with gadolinium-ethoxybenzyl-diethylenetriamine penta-acetate-enhanced MRI in living-donor liver transplantation.

BACKGROUND: A precise estimation of the capacity of the remnant liver following partial liver resection is important. In this study, the regional function of the liver in patients undergoing living-donor liver transplantation was evaluated by gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (EOB)-enhanced MRI, with special reference to the congested region. METHODS: EOB-MRI analysis was performed before hepatectomy in donors, and 7 days after surgery in the donor and recipient. In the hepatocyte phase, from images obtained 15 min after Primovist® injection, the signal intensity in each liver segment was measured and divided by the signal intensity of the erector spinae muscle (liver to muscle ratio, LMR) for standardization. Inter-regional differences in LMRs were analysed in donors and recipients. RESULTS: Thirty-two living donors and 31 recipients undergoing living-donor liver transplantation were enrolled. In donors, the LMRs of the remnant left lobe were almost equivalent among the liver segments. In the remnant right lobe without the middle hepatic vein, the mean(s.d.) LMR for congested segments (S5 and S8) was significantly lower than that for non-congested segments (S6 and S7): 2·60(0·52) versus 3·64(0·56) respectively (P < 0·001). After surgery, values in the non-congested region were almost identical to those in the preoperative donor liver. LMR values in the left and right lobe graft were significantly lower than those in the corresponding segment before donor surgery (P < 0·001). CONCLUSION: The function of the congested region secondary to outflow obstruction in the remnant donor liver was approximately 70 per cent of that in the non-congested region. EOB-MRI is a promising tool to assess regional liver function, with good spatial resolution.

Detectability of hepatocellular carcinoma on gadoxetic acid-enhanced MRI at 3 T in patients with severe liver dysfunction: clinical impact of dual-source parallel radiofrequency excitation.

AIM: To clarify the detectability of hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced MRI at 3 T with dual-source parallel radiofrequency (RF) excitation. MATERIALS AND METHODS: Twelve patients with 26 HCCs who each underwent multidetector row CT (MDCT), gadoxetic acid-enhanced MRI with dual-source parallel RF excitation, and angiography-assisted CT prior to living related-liver transplantation. Three blinded readers independently reviewed the images obtained by each imaging technique for the presence of HCC on a segment-by-segment basis using a five-point confidence scale. The area under the receiver operating characteristic curve (Az), sensitivity, and specificity were compared among the three techniques. RESULTS: The Az values of gadoxetic acid-enhanced MRI were highest for all readers, although no significant difference in Az value among the three methods was obtained. No significant differences in sensitivity or specificity were observed among the three techniques for each reader. CONCLUSION: Gadoxetic acid-enhanced MRI at 3 T with dual-source parallel RF excitation has relatively high-level diagnostic potential for the detection of HCC in patients with severe liver dysfunction, which was equivalent to that of MDCT and angiography-assisted CT. Dual-source parallel RF excitation would have a clinical impact on 3 T MRI of the liver.

Sarcopenia as a predictor of prognosis in patients following hepatectomy for hepatocellular carcinoma.

BACKGROUND: Sarcopenia was identified recently as a poor prognostic factor in patients with cancer. The present study investigated the effect of sarcopenia on short- and long-term outcomes following partial hepatectomy for hepatocellular carcinoma (HCC), and aimed to identify prognostic factors. METHODS: Data were collected retrospectively for all consecutive patients who underwent hepatectomy for HCC with curative intent between January 2004 and December 2009. Patients were assigned to one of two groups according to the presence or absence of sarcopenia, assessed by computed tomographic measurement of muscle mass at the level of the third lumbar vertebra. Clinicopathological, surgical outcome and long-term survival data were analysed. RESULTS: Sarcopenia was present in 75 (40·3 per cent) of 186 patients, and was significantly correlated with female sex, lower body mass index and liver dysfunction, as indicated by abnormal serum albumin levels and indocyanine green retention test at 15 min values. In patients with, and without sarcopenia, the 5-year overall survival rate was 71 and 83·7 per cent respectively, and the 5-year recurrence-free survival rate was 13 and 33·2 per cent respectively. Multivariable analysis revealed that reduced skeletal muscle mass was predictive of an unfavourable prognosis. CONCLUSION: Sarcopenia was predictive of worse overall survival even when adjusted for other known predictors in patients with HCC after partial hepatectomy.

Prostate cancer detection: the value of performing an MRI before a biopsy.

BACKGROUND: In recent years, prostate-specific antigen (PSA) screening has been widely performed. As a result, patients who need to undergo a complete physical examination for an elevated PSA level have been rapidly increasing. Magnetic resonance imaging (MRI) examination has previously been reported to be effective for the detection of prostate cancer. PURPOSE: To evaluate the detectability of prostate cancer by performing MRI before biopsy, and to evaluate the relationship between detectability with MRI and cancer location, Gleason score (GS), and tumor size. MATERIAL AND METHODS: MRI was performed at 1.5 Tesla in 122 consecutive patients before biopsy. The detectability of prostate cancer, including sensitivity and positive predictive value (PPV) of transrectal ultrasonography (TRUS), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) (b=2000 s/mm(2)), apparent diffusion coefficient (ADC) map, and biopsy, was calculated using whole-mount section histopathology as a gold standard. In addition, the relationship between the detectability on each MRI sequence and factors such as cancer location (peripheral zone vs. transition zone), GS 5-10, short-axis diameter (< or =4 mm, 5-9 mm, > or =10 mm), and long-axis diameter (< or =9 mm, 10-19 mm, > or =20 mm) were also evaluated. RESULTS: The sensitivities of TRUS, T2WI, DWI, ADC map, and biopsy were 26.9%, 41.2%, 56.7%, 57.7%, and 75.1%, respectively, and the PPVs of those modalities were 73.0%, 83.0%, 86.4%, 87.2%, and 91.5%, respectively. There was no correlation between the sensitivity of each MRI sequence and cancer location. The sensitivity of each MRI sequence increased as GS and short- and long-axis diameters of cancer lesions increased. CONCLUSION: MRI before a biopsy has a high detectability of prostate cancer, particularly with tumor size of more than 5 mm in short-axis diameter or 10 mm in long-axis diameter.

Microcoil embolization through a downsized coaxial catheter system: an experimental study.

BACKGROUND: Most of the recently developed microcatheters for abdominal angiography still have large diameters at their trailing ends, and thus cannot be used for microcoil embolization in combination with a 3-French (F) system. PURPOSE: To evaluate the in vitro passage of microcoils through a newly developed 2-F microcatheter (Meister Cath Superselective Plus, MC6) that is compatible with a downsized coaxial catheter system (3-F system) in an experimental study. MATERIAL AND METHODS: We evaluated the passage of microcoils through MC6 within a blood vessel model using the saline flush technique. Six types of microcoils and 17 size variations (maximal curled diameter 2-10 mm, total length 20-140 mm) were used. We evaluated the passage and post-deployment shape of the microcoils as well as the volume of saline required to flush them. RESULTS: In the experimental study, all microcoils passed through the MC6 and deployed in a satisfactory manner without catheter occlusion. The mean volumes of saline required to flush the TORNADO (n=1), Reverse TORNADO (n=6), HILAL (n=1), Micronester (n=3), VortX (n=4), and C-Stopper Coil (n=2) were 0.7 ml, 0.58+/-0.20 ml, 0.5 ml, 0.57+/-0.058 ml, 3.5+/-1.5 ml, and 0.70+/-0.14 ml, respectively. There was a statistically significant difference in the mean volume of saline required between the VortX and Reverse TORNADO (P=0.029), and between the VortX and C-Stopper Coil (P=0.031). The VortX required the greatest volume of saline. CONCLUSION: Microcoil embolization through a 3-F system appears to be feasible for the coils examined in this study.

Hepatic falciform ligament artery in patients with chronic liver diseases: detection on computed tomography hepatic arteriography.

BACKGROUND: The detection rate of hepatic falciform ligament artery (FLA) has been reported as ranging from 2-25%. The rate of FLA on laparotomy, however, is reported to be higher, at 68%. PURPOSE: To compare the detection rate of FLA on computed tomography hepatic arteriography (CTHA) with that on angiography and dynamic CT, and to clarify the clinical significance of FLA in patients with chronic liver disease. MATERIAL AND METHODS: 126 consecutive patients underwent CTHA angiography and dynamic CT to evaluate suspected liver tumors. Liver function was classified as follows: normal, n=5; Child-Pugh class A, n=94; B, n=21; and C, n=6. All CT images were obtained using multidetector (MDCT) scanners (Aquilion; Toshiba, Tokyo, Japan). For CTHA, CT images were obtained during contrast material injection through the left hepatic, proper, or common hepatic artery. On CT, FLAs were retrospectively identified within the hepatic falciform ligament and the hepatic round ligament by the paging method on a workstation (TWS-5000; Toshiba, Tokyo, Japan). The detection rates were compared among the three modalities (hepatic arterial phase of dynamic CT, CTHA, and angiography). The calibers of FLA were also correlated with the hepatic function of the patients. RESULTS: The detection rates of FLA by angiography, dynamic CT, and CTHA were 37% (47/126), 10% (13/126), and 77% (97/126), respectively. The calibers of FLA increased as the hepatic function deteriorated (P=0.001). CONCLUSION: The detection rates of FLA with CTHA are far higher than those with angiography and dynamic CT. Careful interpretation with recognition of FLA on CTHA images is important, as inadvertent embolization or chemotherapeutic infusion of the FLA may result in supraumbilical skin rash.

Clinical Outcomes of Living Liver Transplantation According to the Presence of Sarcopenia as Defined by Skeletal Muscle Mass, Hand Grip, and Gait Speed.

BACKGROUND: Sarcopenia is an independent predictor of death after living-donor liver transplantation (LDLT). However, the ability of the Asian Working Group for Sarcopenia criteria for sarcopenia (defined as reduced skeletal muscle mass plus low muscle strength) to predict surgical outcomes in patients who have undergone LDLT has not been determined. METHODS: This study prospectively enrolled 366 patients who underwent LDLT at Kyushu University Hospital. Skeletal muscle area (determined by computed tomography), hand-grip strength, and gait speed were measured in 102 patients before LDLT. We investigated the relationship between sarcopenia and surgical outcomes after LDLT performed in three time periods. RESULTS: The number of patients with lower skeletal muscle area has increased to 52.9% in recent years. The incidence of sarcopenia according to the Asian Working Group for Sarcopenia criteria was 23.5% (24/102). Patients with sarcopenia (defined by skeletal muscle area and functional parameters) had significantly lower skeletal muscle area and weaker hand-grip strength than did those without sarcopenia. Compared with non-sarcopenic patients, patients with sarcopenia also had significantly worse liver function, greater estimated blood loss, greater incidence of postoperative complications of Clavien-Dindo grade IV or greater (including amount of ascites on postoperative day 14, total bilirubin on postoperative day 14, and postoperative sepsis), and longer postoperative hospital stay. Multiple logistic regression analysis revealed sarcopenia as a significant predictor of 6-month mortality. CONCLUSIONS: The combination of skeletal muscle mass and function can predict surgical outcomes in LDLT patients.

High expression of the Cap43 gene in infiltrating macrophages of human renal cell carcinomas.

We used suppression subtractive hybridization to identify highly expressed genes in the cancerous region of human renal cell carcinoma (RCC) compared with noncancerous tissue. Nine genes were identified to show increased expression in the cancerous region compared with the noncancerous region. The nine genes included thymosin beta4, secreted protein acidic and rich in cysteine (SPARC), Cap43, ceruloplasmin, serum amyloid A, osteopontin, heat shock protein 90 (HSP90), LOT1, and casein kinase I. Of these 9 genes, in situ hybridization with 10 clinical samples consistently showed a strong expression of Cap43 mRNA in infiltrating macrophages in RCCs, but not in cancer cells proliferating in an alveolar pattern. However, Cap43 mRNA was also apparently detected in epithelial cells of the renal proximal tubuli in noncancerous tissue. The higher expression of the Cap43 gene in the cancerous region of RCCs appears to depend on macrophage infiltration. Moreover, treatment with phorbol ester resulted in enhanced expression of the Cap43 gene in human monocytic cells in vitro. The expression of the Cap43 gene in infiltrating macrophages is discussed in association with the differentiated or activated status of monocyte/macrophage.

Macrophage infiltration and heme oxygenase-1 expression correlate with angiogenesis in human gliomas.

Macrophages are key participants in angiogenesis. In this study on human brain tumors, we first investigated whether macrophage infiltration is associated with angiogenesis and malignant histological appearance. Immunostaining of macrophages and small vessels in resected glioma specimens indicated that numbers of infiltrating macrophages and small vessel density were higher in glioblastomas than in astrocytomas or anaplastic astrocytomas. Macrophage infiltration was closely correlated with vascular density in human gliomas. Heme oxygenase-1 (HO-1), which is the rate-limiting enzyme in heme catabolism, was also associated with activated macrophages. Expression of mRNA encoding HO-1 was correlated with macrophage infiltration and vascular density in human glioma samples. Infiltrating macrophages were positively stained with anti-HO-1 antibody by immunohistochemical analysis, and in situ hybridization for HO-1 indicated that HO-1 was expressed in infiltrating macrophages in gliomas. HO-1 gene may be a useful marker for macrophage infiltration as well as neovascularization in human gliomas.

Biological implications of macrophage infiltration in human tumor angiogenesis.

Tumor angiogenesis is believed to be induced by increased production of angiogenic factors and decreased production of angiogenic inhibitors by cancer cells, vascular endothelial cells, and other stromal cell types. Most solid tumor cells are surrounded by stroma comprising interstitial connective tissue, blood vessels, fibroblastic cells, etc. Interaction between the stroma and malignant cells appears to have a critical role in the development of tumor neovasculature. We focused on macrophages, which demonstrate wide heterogeneity in biological function and have an essential role in tumor angiogenesis. Macrophages are terminally differentiated cells which produce a number of potent angiogenic cytokines and growth factors such as vascular endothelial growth factor, tumor necrosis factor-alpha, interleukin-8, and basic fibroblast growth factor. They also modulate events in the extracellular matrix through the secretion of extracellular matrix-degrading enzymes and -modulating enzymes. Thus macrophages could influence various stages of angiogenesis either positively or negatively. We found a close correlation between increased macrophage index, malignancy, and high vascular grade in malignant melanoma, and present a model for the possible involvement of activated macrophages in neovascularization in human malignant melanoma.

Angiogenesis factors.

Angiogenesis is a recent highlight in the medical field; the developmental process and pathological conditions for various diseases can be understood from the novel aspect of "angiogenesis". Many angiogenesis-related factors are involved in the development of vessels during embryogenesis (vasculogenesis), as well as the induction of new vessels in response to physiological or pathological stimuli. In particular, the appearance of hemangioblasts, precursor cells for vascular endothelial cells and blood cells, and blood islands are expected to play a "prelude" role in tubulogenesis. Gene knock out mice of vascular endothelial growth factor (VEGF)/VEGF receptor, ephrin-B2, and angiopoietin-1 results in a failure of normal vessels production. Dormant factors derived from proteolytic cleavage of various physiological substrates are expected to balance a homeostasis of "angiogenic states" in the host. Furthermore, angiogenesis under various pathological conditions of malignant tumors, ocular diseases, psoriasis, rheumatoid arthritis, atherosclerosis and other diseases is associated with complex angiogenesis networks, suggesting pleiotropic mechanisms for angiogenesis.

[A safe and simple method of percutaneous transfemoral implantation of a port-catheter access system for hepatic artery chemotherapy infusion].

The purpose of this study was to perform a simple percutaneous transfemoral implantation of a portcatheter access system using a new catheter coating for hepatic artery chemotherapy infusion, and to evaluate the complications of transfemoral infusion port implantation. The methods of treatment for complications were also studied. The port-catheter system was percutaneously implanted via femoral artery access in 180 patients with malignant liver tumors. Blood flow redistribution was performed using embolization coils. An unfixed 5 Fr catheter was placed in a hepatic artery, and connected to a port implanted subcutaneously below the level of the inguinal ligament. The success rate of implantation was 99%. Complications after placement were observed as follows: port system obstruction (9.6%); dislocation of the catheter tip (8.4%); drug toxicity (4.5%); and infection (3.4%). Notable is the avoidance of cerebral infarcts. In 3 of 17 patients with port obstruction, recanalization of the port was achieved. In 11 of 15 patients with catheter dislocation, replacement of the catheter-port system was successful. In 5 patients with hepatic artery occlusion, the replacement of a microcatheter-port access system was achieved, and hepatic artery chemotherapy infusion was resumed. This percutaneous transfemoral implantation of a catheter-port access system would seem to be a very simple and useful method for many clinical doctors, and it may improve the quality of life in patients with an unresectable malignant liver tumor.

Small islet cell tumour in the pancreas: diagnostic value of diffusion-weighted MRI.

We present a case of a small islet cell tumour that was clearly depicted on diffusion-weighted imaging using a free breathing approach and discuss the diagnostic value of this sequence.