Image quality and radiation exposure in CT of the pancreas: 320-MDCT with and without adaptive iterative dose reduction versus 64-MDCT

AIM

To compare the image quality and radiation exposure in computed tomography (CT) of the pancreas acquired using 320-multidetector (MD)CT versus 64-MDCT and to demonstrate the effects of adaptive iterative dose reduction (AIDR) on 320-MDCT.

MATERIALS AND METHODS

One hundred and fifty patients were randomized into three groups including 320-section volume imaging using AIDR (group A), 320-slice volume scan without AIDR (group B), and 64-section helical imaging without AIDR (group C). Transaxial arterial, pancreatic phase, and volume-rendered CT angiographic images were reconstructed. CT radiodensity of the abdominal aorta, pancreas, signal-to-noise ratios (SNR), dose-length products (DLPs; mGy cm), and image quality were measured.

RESULTS

No significant difference in CT radiodensity of the abdominal aorta or pancreas was noted between groups. Mean DLPs were 600.9 ± 145.8, 681.6 ± 97.5, and 1231.5 ± 271.4 in groups A, B, and C, respectively. The DLP was reduced by 51% in group A and 45% in group B compared to group C (p < 0.001). SNRs of the pancreas during the pancreatic phase were comparable between groups A and C, but were significantly lower in group B (p < 0.001). Image quality, including the depiction of some small arterial branches on the arterial and CT angiographic images and the main pancreatic duct on the pancreatic-phase images, were significantly lower in group B than in groups A and C (p = 0.008-0.038).

CONCLUSION

Radiation dose can be markedly reduced for contrast-enhanced CT imaging of the pancreas without compromising image quality using a 320-MDCT with AIDR, compared with 64-section helical CT.

Indications for laparoscopic surgery for Crohn's disease using the Vienna Classification

OBJECTIVE

The aim of this study was to investigate the clinical outcome of laparoscopic surgery for Crohn's disease and clarify the indications using the Vienna Classification.

METHOD

Between September 1994 and July 2004, 107 patients with Crohn's disease underwent 124 procedures. Of these, 91 laparoscopic procedures formed the basis of this study. The Vienna Classification, which consists of three subgroups - age at diagnosis (A1-2), location (L1-4) and behaviour (B1-3) - was applied to compare the conversion to open surgery and incidence of postoperative complications.

RESULTS

Conversion to open surgery was necessary in 12 (13.2%) patients. Major and minor postoperative complications occurred in five (5.5%) and 13 (19.8%) patients respectively. The conversion rate, major and total complications in the B3L3/4 subgroup were significantly greater than in the other subgroups. Multivariate analysis showed that B3L3/4 was the only predictive factor for all complications. However, the incidence of major and all complications in the B3L3/4 subgroup did not differ between the open and laparoscopic surgery groups.

CONCLUSION

Laparoscopic surgery for Crohn's disease is the procedure of choice for all uncomplicated cases (B2L1-4, B3L1/2). For patients in the complicated group (B3L3/4), laparoscopy is also feasible and justified; however, the surgeon must be aware of the propensity for higher rate of conversion.

A case of laparoscopic surgery for blue rubber bleb nevus syndrome

A 33-year-old woman had presented with some cutaneous and gastrointestinal hemangiomas with iron deficiency anemia three years previously and blue rubber bleb nevus syndrome was diagnosed. Although she had taken an iron supplement for three years, she hoped to discontinue it and underwent laparoscopic surgery for nine gastrointestinal hemangiomas. She was discharged on the ninth postoperative day without any complications. She has been fit without iron deficiency anemia for a year since the operation. Blue rubber bleb nevus syndrome is a rare disease accompanied with cutaneous and gastrointestinal vascular malformations and about 150 cases have been reported. To the best of our knowledge, this is the first report of blue rubber bleb nevus syndrome with small and large intestinal lesions that were treated with laparoscopic surgery.

Short- and midterm outcomes of laparoscopic surgery compared for 131 patients with rectal and rectosigmoid cancer

BACKGROUND

This study aimed to clarify and compare the short- and midterm surgical outcomes of laparoscopic surgery for rectal and rectosigmoid cancer.

METHODS

Between June 1992 and December 2004, 131 selected patients with cancer of the rectum (n = 60) and rectosigmoid (n = 71) underwent laparoscopic surgery. The indications for laparoscopy included a preoperative diagnosis of T1/T2 tumor in the rectum and T1-T3 tumors in the rectosigmoid.

RESULTS

The mean follow-up period was 42 months. The procedures included anterior resection for 117 patients, abdominoperineal resection for 11 patients, Hartmann's procedure for 1 patient, and restorative proctocolectomy for 1 patient. Conversion to an open procedure occurred for four patients (3.1%). Postoperative complications developed in 29 patients (22.1%), including anastomotic leakage in 14 patients (11.8%). The length of hospital stay for the rectal cases was significantly longer than for the rectosigmoid cases (10 vs 7 days; p = 0.0049). The tumor node metastasis (TNM) stages included 0 (n = 14), I (n = 72), II (n = 15), III (n = 29), and IV (n = 1). Recurrences were experienced by 13 patients, including local recurrence (n = 7) and recurrences involving the liver ((n = 2), lung (n = 3), and distant lymph nodes (n = 1). The 5-year disease-free and overall survival rates were, respectively 91.7% and 97.9% for stage I, 86.7% and 90.9% for stage II, and 77.1% and 90.0% for stage III.

CONCLUSIONS

Laparoscopic surgery is feasible and safe for selected patients with rectal or rectosigmoid cancer. The selected patients in this study experienced favorable short- and midterm outcomes.

The application of a new stapling device for open surgery (Contour Curved Cutter Stapler) in the laparoscopic resection of rectal cancer

Anastomotic leakage is a serious problem in the laparoscopic resection of rectal cancer. Although stapling devices and techniques for colorectal or coloanal anastomosis have been improved, laparoscopic anastomosis is still technically difficult and the rate of leakage is high. To resolve this problem, a new stapling device (the Contour Curved Cutter Stapler) for open surgery was applied to the laparoscopic resection of rectal cancer. After intracorporeal mobilization and vessel ligation, a 6-cm Pfannenstiel incision was made to insert the device into the peritoneal cavity, and a hand access device was placed on the site. The head of the device was put through a cutoff of the middle finger of a surgical glove, after which the wrist of the glove was attached to the hand access device. To prevent leakage of CO2 gas through the gap between the shaft and the glove, the shaft covered by the glove was tied, and the gap was filled with bone wax. After re-creation of the pneumoperitoneum, the rectum was transected with the stapling device, and the anastomosis was accomplished by the double stapling technique. This technique enabled a reliable transection of the rectum because of the easy handling of the device and the wide laparoscopic view of the lower rectum in the deep pelvis.

Long-term outcome of per anum intersphincteric rectal dissection with direct coloanal anastomosis for lower rectal cancer

OBJECTIVE

The authors have performed per anum intersphincteric rectal dissection. With direct coloanal anastomosis for cases of lower rectal cancer in which the distal surgical margin is difficult to secure by the double stapling technique. The aim of this study was to evaluate the long-term outcome and to clarify the surgical indications for this operation.

PATIENTS AND METHODS

Between 1993 and 2002, 31 patients underwent per anum intersphincteric rectal dissection with direct coloanal anastomosis. Of these, two patients (one stage 0 and one stage IV) were excluded from the analysis of oncological outcome. The remaining 29 patients formed the basis of this study. The median follow-up was 57 months (range 6-106 months).

RESULTS

Local recurrence and distant metastasis developed in 9 and 3 patients, respectively. Local recurrence rate for pT1 was significantly lower than that for pT2/T3 disease. The local recurrence rate cases with tumours less than 3 cm was significantly lower than that for tumours sized 3 cm or more. The distant metastasis rate for cases with lymph node metastasis was significantly higher than that for cases without lymph node metastasis. There was an association between distant metastasis and TNM or pT stage. The overall survival rates for stage I, II and III were 85%, 80% and 89%, respectively. No significant difference was seen in total Cleveland Clinic incontinence score between per anum intersphincteric rectal dissection with direct coloanal anastomosis and the double stapling technique.

CONCLUSION

The surgical indications of this operation should be limited to patients with T1 rectal cancer or tumours less than 3 cm.

Impact of visceral obesity on surgical outcome after laparoscopic surgery for rectal cancer

Complication rate higher in viscerally obese

Spinal subarachnoid hematoma compressing the conus medullaris and associated with neurofibromatosis type 2

STUDY DESIGN

Report of a case of subarachnoid hematoma associated with neurofibromatosis type 2 (NF2) in a 10-year-old girl.

OBJECTIVE

To report a rare case of subarachnoid spontaneous hematoma associated with NF2, with no evidence of trauma.

SETTING

Gifu, Japan.

METHODS

The patient presented with severe leg pain. MRI revealed a subarachnoid hematoma at the level of L2 and a spinal cord tumor at the level of T6. The subarachnoid hematoma had low and high heterogeneous signal intensity on the T1-weighted image and low signal intensity on the T2-weighted image, indicating the presence of extracellular methemoglobin. The tumor and hematoma were resected.

RESULTS

Pathological analysis demonstrated that the surgical specimen removed from the area of L2 was a hematoma and the specimen from T6 was a neurinoma. At follow-up 1 year after surgery, the girl remained neurologically asymptomatic.

CONCLUSIONS

This rare case of spinal subarachnoid hematoma was associated with NF2. MRI was useful in establishing the diagnosis.

Laparoscopic surgery for recurrent Crohn's disease

BACKGROUND

The aim of this study was to assess the feasibility of laparoscopic surgery for recurrent Crohn's disease, and the role of repeated laparoscopy in reoperation.

METHODS

Between January 1994 and May 2002, 61 laparoscopic operations were attempted in 52 patients with ileal or ileocolonic Crohn's disease. Of these, 16 procedures were performed for recurrence at the anastomotic site (recurrent group). The remaining 45 operations were performed as primary procedures (control group). The median follow-up was 48 (range 3-90) months.

RESULTS

The median time to reoperation was 46 months. The incidence of enteric fistula and the conversion rate did not differ significantly between the two groups. Although the operating time was significantly longer in the recurrent group, there were no differences in the rate of postoperative complications (three in the recurrent group and six in the control group) and hospital stay (both median 8 days).

CONCLUSION

Laparoscopic surgery for recurrent Crohn's disease is feasible in selected patients without an increase in conversion rate or postoperative complications.

Pseudothrombosis in the portal venous system: a potential pitfall with gadolinium-enhanced dynamic gradient-recalled echo imaging of the liver

Gadolinium-enhanced dynamic magnetic resonance (MR) images in 90 patients were reviewed to assess the artifacts mimicking portal venous thrombosis. The incidence of definite signal-intensity decrease mimicking pathologic condition was higher (P < 0.01) in the right (8%) and left (9%) portal vein branches and portal trunk (6%) than in the splenic (0%) or superior mesenteric (1%) vein with equilibrium-phase images. Radiologists should remember that dynamic MR images occasionally show signal-intensity decrease mimicking portal venous thrombosis due to flow artifact.

An interaction between human colon carcinoma cells and hepatocytes activates transforming growth factor-beta1 in vitro

We established in vitro heterotypic co-cultures of a human colon carcinoma cell line, HT-29, and a human hepatocyte line, tPH5CH, using transwells to investigate possible interactions between colon carcinoma cells and hepatocytes during the metastatic process. Co-culture, but not HT-29 conditioned medium, inhibited tPH5CH cell proliferation, and this inhibition was blocked by an anti-TGF-beta1 antibody. Significantly more activated TGF-beta1 was released by co-culture than by each cell line cultured alone, whereas there were no significant differences between the total TGF-beta1 released by the individual cultured cell lines and that released by co-culture. These data indicate that an interaction between human colon carcinoma cells and hepatocytes activates TGF-beta1 in vitro.

A streptococcal preparation (OK-432) enhances monoclonal antibody NCC-ST-421 cytotoxicity against human colon cancer

The murine IgG3 monoclonal antibody NCC-ST-421 (ST-421), raised against human gastric cancer, shows strong reactivity with the Le(a)/Le(a) (al-fucosylated extended type 1 chain) antigen expressed on gastrointestinal (GI) cancer cells. ST-421 is capable of mediating both antibody-dependent cellular cytotoxicity (ADCC) by human peripheral blood lymphocytes (PBL), and complement dependent cytotoxicity (CDC). We investigated combination immunotherapy with OK-432, a streptococcal preparation, and ST-421 in vitro and in vivo. ADCC against Colo 205 (a human colon cancer cell line) was enhanced 2 to 3 fold after preincubation of PBL with OK-432 in vitro. These effect's were strongest when PBL were preincubated with OK-432 at a concentration of 0.5 ng/ml for 24 hours. In vivo, a human colon cancer xenograft model exhibited significant growth suppression after combined treatment with ST-421 and OK-432. Such combination immunotherapy may therefore be clinically useful in GI cancer.

Increased ubiquitin immunoreactivity in hepatocellular carcinomas and precancerous lesions of the liver

BACKGROUND/AIMS

Ubiquitin covalently attaches to abnormal and short-lived proteins, thus marking them for ATP-dependent proteolysis in eukaryotic cells. Increased ubiquitin immunoreactivity was recently observed immunohistochemically in human malignant tumors. To clarify the change in protein metabolism during hepatocarcinogenesis, we studied ubiquitin immunoreactivity in hepatocellular carcinomas (HCCs) and precancerous lesions using immunohistochemistry and immunoblot analysis.

METHODS

A total of 72 HCCs (37 advanced, 19 early, 16 early-advanced (advanced HCC component in early HCC nodule) type HCCs) and 18 precancerous lesions (8 atypical adenomatous hyperplasias (AAHs), 10 adenomatous hyperplasias (AHs)) were studied immunohistochemically. Immunoblot analysis was also performed in advanced HCC and early HCC cases.

RESULTS

Non-tumorous hepatocytes were either immunonegative or weakly stained in their nuclei. Advanced HCCs showed strong immunoreactivity in most cases, while early HCCs showed relatively weaker immunoreactivity. In 14 of 16 early-advanced type tumors, the inner portion of the nodules, which corresponds to advanced HCC, showed stronger immunoreactivity than the outer low-grade portion. In 8 of 8 AAHs and 7 of 10 AHs, positive but weak staining was found. Immunoblot analysis showed an increase in 42 kDa ubiquitinated protein(s) in 8 of 16 advanced HCC cases (50%) and in 1 of 6 early HCC cases (16.7%), as well as an increase in several other bands in tumor tissues.

CONCLUSIONS

The intensity of ubiquitin staining appeared to increase in a stepwise manner from AH to advanced HCC, and the results suggest a possible correlation between changes in the ubiquitinated proteins and multistep hepatocarcinogenesis.

Immunoreaction at 43 kDa with anti-ubiquitin antibody in breast neoplasms

Protein ubiquitination has been implicated in ATP-dependent protein turnover and normal cell proliferation. To investigate whether the ubiquitin-mediated system is functionally involved in the cancerous state, we examined changes in protein ubiquitination in 52 surgically resected primary breast tumors. Immunohistochemically, ubiquitin (Ub) was identified in the cytoplasm of cancer cells, which were stained more strongly than adjacent normal ductal epithelium. Corresponding immunoblot analysis of normal and neoplastic regions of human breast showed that the immunoreaction for Ub at about 43 kDa was increased in all of the tumors (100%), regardless of the clinical stage or histologic grade. This protein, which gave a single spot on two-dimensional gel electrophoresis, had partial amino acid sequences which were identical to those of actin family members. Our results suggest that ubiquitination of this 43-kDa protein may be involved in the carcinogenesis or biological characteristics of human breast neoplasms.

Human colorectal carcinomas specifically accumulate Mr 42,000 ubiquitin-conjugated cytokeratin 8 fragments

Recent studies have shown that various tumor cells accumulate ubiquitin (Ub)-conjugated proteins, the profiles of which differ from those of normal cells. To identify the Ub-conjugated proteins accumulated specifically by human carcinoma cells, a two-dimensional immunoblot analysis of 31 surgically resected human primary colorectal carcinoma tissues was performed using an anti-Ub monoclonal antibody, KM691. Two distinct Mr 42,000 and 45,000 proteins in the Triton X-insoluble fractions of carcinoma tissues reacted with this antibody, whereas only one Mr 45,000 protein reacted in normal tissues. The Mr 42,000 Ub-conjugated proteins were specific to carcinoma tissues from 25 patients (80.6%). One of the purified Mr 42,000 proteins was digested with Achromobacter protease I. This protein was identified as a cytokeratin 8 (CK 8) fragment based on both molecular mass determination and molecular mass searching of Achromobacter protease I-digested fragments of proteins registered in a protein sequence data base. Two-dimensional immunoblot analysis with an anti-CK 8 antibody confirmed that all of the Mr 42,000 proteins were CK 8 degradation products. These results demonstrate that human colorectal carcinomas specifically accumulate Mr 42,000 Ub-conjugated CK 8 fragments. This accumulation was observed frequently not only in advanced (18/22, 81.8%), but also in early stage cases (7/9, 77.8%), suggesting that it occurs even in the early stages of colorectal carcinoma progression.

A metastatic model of human colon cancer constructed using cecal implantation of cancer tissue in nude mice

COL-2-JCK, a human colon cancer xenograft line able to be transplanted into nude mice, was implanted in the subserosal layer of the cecum, either as cancer tissue or as a single cell suspension. When cancer tissue was used for the cecal implantation, 100% extensive local tumor growth and a high incidence of metastases to the regional lymph nodes, peritoneum, liver, and lung was observed. In contrast, when the cell suspension of this line was injected into the cecal wall, no metastases were observed, with significantly reduced local tumor growth. The use of cancer tissue maintaining the original cancer tissue structure is therefore considered imperative for allowing full expression of the biological characteristics of cancer cells. This nude mouse model using the cecal implantation of cancer tissue should thus prompt further study on the biology of human colon cancer.

Experimental cancer chemotherapy using a liver metastatic model of human colon cancer transplanted into the spleen of severe combined immunodeficient mice

We have developed a liver metastatic model of human colon cancer using severe combined immunodeficient (SCID) mice. Liver metastases were observed in all the SCID mice on day 28 after intrasplenic injection with 5 x 10(6) dissociated tumor cells of COL-2-JCK, a human colon cancer strain serially transplanted in nude mice. When this model was applied for chemotherapeutic experiments, 5-fluorouracil (5-FU) demonstrated significant antitumor effects in preventing liver metastases, whereas the efficacy of 5-FU was limited in the currently used sc-ip chemosensitivity assay in nude mice. When the human LDH-5 isozyme was evaluated in the homogenized metastatic liver tissue of SCID mice, a good correlation was obtained between the liver tumor weights and LDH-5 isozyme, suggesting that it could be a promising quantitative indicator for metastases. This model would be useful for further studies on the treatment of liver metastases of colon cancer.

A suitable model for experimental liver metastasis of human colon cancer xenografts using mice with severe combined immunodeficiency

Studies on liver metastasis of human colon cancer are limited because of a lack of suitable animal models. In this study, the usefulness of mice with severe combined immunodeficiency (SCID), which congenitally lack functional T and B lymphocytes, was evaluated in comparison with currently available nude mice. Three human colon cancer xenografts transplantable into nude mice were disaggregated enzymatically to obtain tumor cell suspensions, and implanted intrasplenically into SCID and nude mice. The incidence of splenic tumorigenesis and of liver metastases were significantly greater in SCID mice for all xenografts, in comparison with nude mice. In total, 33 of 36 SCID mice and 17 of 43 nude mice developed liver metastases. On the basis of this result, we conclude that SCID mice would be a more suitable model than nude mice for studying liver metastasis of human colon cancer.

Modulation by l-leucovorin of 1-hexylcarbamoyl-5-fluorouracil antitumor activity on human gastric and colon carcinomas serially transplanted into nude mice

Experimental biochemical modulation of 1-hexylcarbamoyl-5-fluorouracil (HCFU) with l-leucovorin (LV) was carried out using human gastric (H-111) and colon (Co-4) carcinoma xenografts serially transplanted into nude mice. Thirty-five or 70 mg/kg HCFU dissolved in 0.2 ml of 1% hydroxymethyl cellulose was administered po daily for 3 weeks except Sundays, and 50, 100, 200 or 300 mg/kg LV dissolved in 0.2 ml physiological saline was administered po 30 min before administration of HCFU. The biochemically modulated antitumor activity was evaluated in terms of actual tumor weight, the relative mean tumor weight and the degree of inhibition of thymidylate synthetase (TS) in the tumors at the end of the experiments, assayed according to the method of Spears et al. Although 35 mg/kg HCFU was ineffective against gastric carcinoma H-111, combination with 200 or 300 mg/kg LV resulted in a positive antitumor effect of HCFU on this strain without any increase of side effects in terms of body weight loss and mouse mortality. The colon carcinoma strain Co-4 showed marginal sensitivity to HCFU (35 mg/kg) alone, but 50 or 100 mg/kg LV modulated the antitumor activity of HCFU on Co-4 to produce a significant positive effect without any increase in toxicity, and HCFU administered with 100 mg/kg LV was more effective than the maximum tolerated dose of HCFU (70 mg/kg) alone. The TS inhibition rate was closely related to the biochemical modulation of HCFU antitumor activity by LV, suggesting that the modulation involves an increase of the ternary complex of TS, 5,10-methylene tetrahydrofolate from LV and 5-fluorodeoxyuridine 5'-monophosphate (FdUMP). Combination of HCFU and LV is therefore thought to be useful in increasing the antitumor activity of HCFU on gastrointestinal carcinomas without enhancing its toxicity.

Orthotopic reconstitution of human small-cell lung carcinoma after intravenous transplantation in SCID mice

We have constructed an orthotopically reconstituted model of human small-cell lung carcinoma (SCLC) by intravenous transplantation in severe combined immunodeficient (SCID) mice. Two human SCLC xenografts, H-69 and Lu-130, were disaggregated and injected through the tail vein of SCID mice. Human SCLCs were orthotopically reconstituted with multi-focal lung tumor growth in all SCID mice after intravenous injection of 5 x 10(6) tumor cells per mouse. The heart and liver were also seeded with actively growing SCLC. This orthotopic reconstitution model of human SCLC in SCID mice should be useful for further studies on the biological behavior and treatment of human SCLC.

Increased drug resistance of cultured human cancer cell lines in three-dimensional cellular growth assay using collagen gel matrix

We have conducted a three-dimensional cellular growth assay using collagen gel matrix with an endpoint of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay, on four human gastric and colonic cancer cell lines. Three-dimensionally growing cells in collagen gel matrix were 2- to 180-fold more resistant to mitomycin C, doxorubicin, 5-fluorouracil, and cisplatin than those in monolayer culture, and these resistances were increased further when the cells increased their three-dimensionality. Furthermore, the influence of fibroblasts in the collagen gel matrix on the chemosensitivity of cancer cells was less than that in monolayer culture. Since this new assay using collagen gel matrix with an endpoint of the MTT assay was able to detect the increase of drug resistance of human cancer cell lines by three-dimensional cellular growth using a simple and convenient procedure, it was considered to be more useful than conventional monolayer cultures for evaluating the chemosensitivity of cancer cells.

A case of Menetrier's disease associated with protein-losing gastropathy and abnormal serum complement profile

A 44-year-old man with Menetrier's disease associated with protein-losing gastropathy and with abnormal serum complement profile is reported. He was treated by an antifibrinolytic compound tranexamic acid (trans-AMCHA) since he was found to have elevated fibrinolytic activity in the biopsied gastric mucosa. The therapy brought his serum protein from 3.8 g/dl to 5.6g/dl, however could not reduce his mucosal disorder. Substitution of a placebo for trans-AMCHA resulted in marked depression of his serum protein to 3.7 g/dl. It was concluded that trans-AMCHA was effective in raising his serum protein to a certain extent but failed to block the vicious circle of "mucosal disorder", "increased tissue fibrinolysis" and "hypoproteinemia" (Kondo, M. et al. Gastroenterology 70, 1045, 1976). Abnormal serum complement profile seen in this patient was found to be due to cold activation of the classical complement pathway (Kondo, M. et al. J. Immunol. 117, 486, 1976). Although no correlation between the phenomenon and Menetrier's disease has been clarified yet, the appearance of wheezing as in asthma when exposed to cold suggested that cold activation of complement occurred in vivo and resulted in increasing of the vascular permeability in the lungs.