Gene expression profile predicts patient survival of gastric cancer after surgical resection

PURPOSE

This study was conducted to characterize gene expression profile of survival in patients with surgically curable gastric cancer by using an in-house membrane microarray and developing a survival prediction model.

MATERIALS AND METHODS

Data of cDNA microarrays were obtained from 18 pairs of cancerous and noncancerous gastric tissues. Nine patients who survived > 30 months were identified as good survival, and the other nine, who survived < 12 months, were identified as poor survival. Supervised analysis was performed to identify a gene expression profile by good and poor survival. Semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to confirm the microarray data in 10 patients with sufficient RNA. Using these 10 patients and another 10 patients selected randomly from 40 newly enrolled patients as the training group, the RT-PCR status of the confirmed genes was used for predicting good versus poor survival. Finally, the prediction model was tested in the remaining 30 newly enrolled gastric cancer patients.

RESULTS

A survival prediction model consisting of three genes (CD36, SLAM, PIM-1) was developed. This model could correctly predict poor or good survival in 23 (76.7%) of 30 newly enrolled patients, and yielded a specificity of 80% and a sensitivity of 73.3%. The survival rate of the patients predicted to have good survival was significantly higher than that of those predicted to have poor survival in the test group as a whole (N = 30; P = .00531) and in stage III patients (n = 16; P = .04467).

CONCLUSION

The semiquantitative RT-PCR gene expression profiling of three genes extracted from microarray study can accurately predict surgery-related outcome in gastric cancer patients.

Is imatinib justified as an adjuvant chemotherapy for patients with recurrent gastrointestinal stromal tumors

Imatinib, an inhibitor of the tyrosine kinase activity of c-kit, was used as an adjuvant chemotherapy in two patients who underwent curative surgery for recurrent gastrointestinal stromal tumors. One patient has maintained tumor-free survival for 12 months, while the other had rapid recurrence and metastasis of tumors 3 months after he discontinued the drug. The indication and effects of imatinib for prevention of recurrence of GIST after ablative surgery were discussed.

Cancer-specific activation of the survivin promoter and its potential use in gene therapy

Survivin is expressed in many cancers but not in normal adult tissues and is transcriptionally regulated. To test the feasibility of using the survivin promoter to induce cancer-specific transgene expression in lung cancer gene therapy, a vector expressing a luciferase gene driven by the survivin promoter was constructed and evaluated in vitro and in vivo. We found that the survivin promoter was generally more highly activated in cancer cell lines than in normal and immortalized normal cell lines. When delivered intravenously by DNA:liposome complexes, the survivin promoter was more than 200 times more cancer specific than the cytomegalovirus promoter in vivo. To identify lung cancer patients who may benefit from gene therapy with the survivin promoter, we measured survivin protein expression in surgical specimens of 75 non-small-cell lung cancers and 10 normal lung tissues by immunohistochemical staining and found that survivin is expressed in most of the non-small-cell lung cancers tested (81%, 61 of 75) but none of the normal lung tissues. The survivin promoter also induced transgene expression of a mutant Bik in cancer cells, which suppressed the growth of cancer cells in vitro and in vivo. These results indicate that the survivin promoter is a cancer-specific promoter for various cancers and that it may be useful in cancer gene therapy.

Connective tissue growth factor inhibits metastasis and acts as an independent prognostic marker in colorectal cancer

BACKGROUND & AIMS

Connective tissue growth factor (CTGF) has been shown to be implicated in tumor development and progression. The aim of this study was to investigate the role of CTGF in progression of colorectal cancer (CRC).

METHODS

Immunohistochemical staining of specimens from 119 patients with CRC was performed. Liposome-mediated transfection was used to introduce a CTGF expression vector into CRC cell lines. Transfectants were tested in invasive ability and experimental hepatic metastasis in BALB/c mice. Furthermore, a FOPflash/TOPflash reporter assay was performed to investigate CTGF on the beta-catenin/T-cell factor signaling pathway.

RESULTS

Patients with stage II and stage III CRC whose tumors displayed high CTGF expression had a significantly higher overall survival and a disease-free advantage over patients with CRC with low CTGF expression. Alterations in the CTGF level in CRC cell lines modulated their invasive ability with an inverse correlation. In addition, a reduction in the CTGF level of CT26 cells after stable transfection with antisense CTGF resulted in increased liver metastasis in BALB/c mice. The activity of the beta-catenin/T-cell factor signaling pathway and its downstream effector gene matrix metalloproteinase 7 in these CTGF-transfected cells was strongly attenuated. Blockage of matrix metalloproteinase 7 with its neutralizing antibodies inhibited increased invasiveness in antisense CTGF-transfected CT26 cells.

CONCLUSIONS

Our results implicate CTGF as a key regulator of CRC invasion and metastasis, and it appears to be a useful and better prognosis factor for patients with stage II and stage III CRC.

The significance of placenta growth factor in angiogenesis and clinical outcome of human gastric cancer

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family of proangiogenic factors and its overexpression has been linked to pathological angiogenesis. We studied the relationship between the expression of PlGF and VEGF in human gastric cancer tissues and microvessel density (MVD), as well as clinical outcome in 79 patients with gastric cancer by using an enzyme immunoassay for PlGF and VEGF expression levels in gastric cancers and surrounding non-cancerous mucosa. PlGF protein levels were significantly higher in tumor than in the corresponding non-tumorous mucosa (median value 48.5 vs 9.8 pg/mg, P < 0.001). In contrast, VEGF protein levels were not (66.7 vs 80.7 pg/mg, P = 0.522). VEGF expression level was not significantly correlated with MVD, patient survival, and clinicopathological factors except Lauren classification in this study. PlGF may be an important angiogenic factor in human gastric cancer, and PlGF expression level was significantly correlated with serosal invasion, positive lymph node metastases, tumor stages, and patient survival.

Expression of eukaryotic initiation factor 4E in gastric adenocarcinoma and its association with clinical outcome

BACKGROUND AND OBJECTIVES

Overexpression of eIF4E can result in oncogenic transformation and uncontrolled growth of mammalian cells, presumably by facilitating the expression of growth-control gene products, which are normally translationally repressed. Overexpression of eIF4E was present in human breast carcinoma and human head and neck squamous cell carcinoma, and may be of prognostic value in breast carcinomas. In order to elucidate the clinical significance of eIF4E expression, this study was conducted to quantify expression of eIF4E in human gastric cancer tissue and correlate them with clinicopathological factors and patient survival.

METHODS

Specimens from sixty-nine patients with gastric adenocarcinoma were analyzed and eIF4E overexpression was quantified by Western blot analysis. Quantification of eIF4E levels in cancer was expressed relative to controls from non-tumorous mucosa of the same patients. Confirmation of eIF4E overexpression at the cellular level was performed using immunohistochemical staining. The association of clinicopathologic factors and survival with eIF4E expression was analyzed.

RESULTS

In non-tumorous parts of specimens, overexpression of eIF4E was always present in gastric glands but not in gastric pits lining mucosa, and it was also expressed in the areas of intestinal metaplasia and dysplasia. In the 69 specimens, the mean eIF4E expression was 5.77 +/- 8.55-fold (mean +/- standard deviation), ranged from from 0.1-fold to 38-fold. The degree of eIF4E expression appeared to be independent of invasion depth of tumor, lymph node metastasis, Lauren classification, Borrmann types, and Helicobacter pylori infection. Marked overexpression of eIF4E (more than seven-fold) was correlated with tumor vascular invasion (P = 0.046, Fisher exact-test). The survival rate of the patients with underexpression or mild overexpression of eIF4E (less than sevenfold) was significantly higher than that with marked eIF4E overexpression (more than sevenfold) (P = 0.01734, log rank test).

CONCLUSIONS

Marked eIF4E overexpression in gastric cancer was found to be associated with vascular invasion. The prognosis for gastric cancer patients with marked overexpression of eIF4E was worse than those with underexpression. It may serve as an additional prognostic and therapeutic factor in gastric cancer, and deserves further investigation.

The protective role of heme oxygenase-1 on the liver after hypoxic preconditioning in rats

BACKGROUND

Hypoxic preconditioning (HP) confers cytoprotection against ischemia/reperfusion (I/R) injury. This effect is in part attributable to the induction of heme oxygenase (HO)-1. This experiment evaluates liver cell damage after I/R injury in HP rats.

METHODS

HP rats were prepared by exposure (15 hr/day) to an altitude chamber (5500 m) for 2 weeks. Partial hepatic ischemia was produced in the left lobes for 45 min followed by 180 min of reperfusion. Zinc (Zn) protoporphyrin (PP), a specific inhibitor of HO enzymatic activity, was subcutaneously injected 1 hr before the I/R injury into separate groups of sea-level (SL) control and HP rats. Serum alanine aminotransferase (ALT) levels, liver HO-1 mRNA and protein, and HO enzymatic activity were measured.

RESULTS

HO-1 was induced in the livers of rats exposed to HP. The levels of HO-1 mRNA and protein were obviously overexpressed after 2 weeks of HP. HP diminished the elevation of serum ALT levels after I/R injury (83.7+/- 4.9 U/L) when compared with SL controls (280.8+/-19.4 U/L) and HP+ZnPP-pretreated groups (151.3+/-4.4 U/L). The HO activity in treated rats also was correlated with these results (237.9+/-19.8 pmol/mg of protein per hour for the HP group, 164.3+/-12.7 pmol/mg of protein per hour for the HP+ZnPP group, and 182.6+/-8 pmol/mg of protein per hour for the SL controls).

CONCLUSIONS

The authors' results indicated that the induction of HO-1 in hypoxic preconditioning played a protective role against hepatic I/R injury.

Intravasation-Related Metastatic Factors in Colorectal Cancer

Alterations in adhesion molecules, angiogenesis, and matrix metalloproteinases have been associated with metastasis and intravasation. The present study investigated the role of these metastatic factors in the context of primary colorectal tumor. Intravasated colorectal epithelial cells were detected by an RT-PCR assay, and the expression of E-cadherin, alpha-catenin, or beta-catenin as well as the vascularity of tumor were assessed by immunohistochemical staining. Activity of matrix metalloproteinase was assessed by gelatin zymography. The tumor venous blood was positive for guanylyl cyclase C (GCC) mRNA expression in 40 of 68 patients, but alteration in expression of E-cadherin, alpha-catenin, or beta-catenin was not significantly associated with the presence of colorectal epithelial cells in paired portal venous blood. Further, matrix metalloproteinase activity did not correlate with the presence of intravasated colorectal epithelial cells. Multivariate analysis demonstrated that the only factor associated with intravasated colorectal tumor cells was the vascularity of the tumor. Thus, metastasis of colon cancer may result from passive entry into the circulation secondary to angiogenic factors and does not appear to involve other metastatic factors studied in our experiments.

Microbiology difference between colonized catheters and catheter-related bloodstream infections

BACKGROUND/AIMS

Central vein catheters for patients receiving total parenteral nutrition have a high incidence of colonized catheters and catheter-related bloodstream infections. However, the actual incidence and bacterial pattern have not been well studied. This study was undertaken to investigate the difference in bacteriology between colonized catheters and catheter-related bloodstream infections.

METHODOLOGY

From January 1997 to March 1998, 354 patients receiving total parenteral nutrition were included in this study. The patients ranged in age from 49 to 80 years, 151 women and 203 men. Colonized catheters and catheter-related bloodstream infections were defined.

RESULTS

The culture was performed in 249 catheter tips (249 of 614, 40.6%). Sixty tips were found to have organisms. The organisms cultured from colonized catheters were Gram(+) aerobic bacteria (34, 56.7%), fungi (14, 23.3%), and Gram(-) aerobic bacteria (12, 20%). The organisms cultured from catheter-related bloodstream infections were fungi (16, 64%), Gram(-) aerobic bacteria (5, 20%), and Gram(+) aerobic bacteria (4, 16%). Dermatogenic infection in colonized catheters should be stressed, but systemic fungal infection in catheter-related bloodstream infections should be emphasized.

CONCLUSIONS

A striking difference exists in bacterial species between colonized catheters and catheter-related bloodstream infections. Further studies on different treatment strategy for colonized catheters and catheter-related bloodstream infections should be undertaken. The combined approach of a total parenteral nutrition team, sterile protocols, and early diagnosis of fungemia should be advocated for the total parenteral nutrition patients.

Impact of endoscopic ultrasound combined with fine-needle aspiration biopsy in the management of esophageal cancer

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound (EUS) in combination with fine-needle aspiration biopsy (FNA) is a highly accurate method for the preoperative staging of esophageal cancer. Its impact on medical decision-making and the cost of care is unknown. This prospective case series was undertaken in order to determine the impact of EUS in combination with FNA on patients' choice of therapy and on the cost of care.

PATIENTS AND METHODS

Sixty consecutive patients with esophageal cancer, referred for preoperative EUS staging in a large tertiary-care academic medical center, were enrolled. The accuracy of EUS, the impact of EUS-based staging on the patients' choice of therapy, and costs were studied.

RESULTS

The accuracy rates for EUS combined with FNA in tumor and lymph-node staging were 83 % and 89 %, respectively. Twenty-five patients (42 %) had EUS stage I and II and were candidates for curative surgery. Twenty-eight patients (47 %) had stage III, and seven (12 %) had stage IV. All patients with stage I had surgery, while all patients with stage IV had medical therapy. The majority (62 %) of patients with stage II had surgery, while only a minority (25 %) of patients with stage III had surgery. Thirty-six patients (60 %) underwent medical therapy. Patients' medical decisions in favor of surgical or medical therapy correlated strongly with the results of their EUS staging ( P = 0.005), but not with age, sex, or referring physicians (surgeons vs. nonsurgeons). EUS-guided therapy potentially decreased the cost of care by $ 740 424 ($ 12 340/patient) by reducing the number of thoracotomies.

CONCLUSIONS

Patients' decisions regarding therapy correlated with their overall tumor staging, suggesting that the information provided by EUS played a significant role in patients' decision-making. The use of EUS in combination with FNA reduces the cost of managing patients with esophageal cancer.

Effects of octreotide on epidermal growth factor receptor, tissue plasminogen activator, and plasminogen activator inhibitor during intraperitoneal adhesion formation

BACKGROUND

Intraperitoneal adhesions remain a problem after abdominal surgery. Octreotide has been proved to be able to reduce the number, strength, and extent of fibrous bands at and away from the anastomotic site in an animal model of rats with intestinal resection and reanastomosis. The aim of the present study was to investigate whether epidermal growth factor receptor (EGF-R), tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI) are involved in this process.

METHODS

Laparotomy with intestinal resection and reanastomosis was performed on 60 male Wistar rats. All rats were randomly assigned to five groups: receiving no medication (control; C), normal saline (NS), octreotide solution peritoneal irrigation (Oc), octreotide intramuscular injection (IM), and Oc plus octreotide intramuscular injection (Oc + IM). The concentrations of serum EGF-R, plasma tPA, PAI-1, and PAI-2, and the strength of wound healing were measured.

RESULTS

The serum EGF-R concentration showed no significant change from the preoperative level in the C and NS groups 7 and 14 days after the abdominal surgery. However, it decreased significantly on postoperative days 7 and 14 in groups Oc, IM, and Oc + IM ( P < 0.05). The plasma tPA concentrations were significantly higher than the preoperative level in all groups of rats on postoperative day 7. The levels were higher in groups Oc, IM, and Oc + IM than in group C or group NS at that time ( P < 0.05). On postoperative day 14, the plasma tPA concentrations had returned to the preoperative level in group C and group NS. However, the concentrations in groups Oc, IM, and Oc + IM still remained at a significantly higher level than the concentrations in group C and group NS. The plasma PAI-1 and PAI-2 concentrations showed no significant difference from the preoperative level in group C and group NS on days 7 and 14 after the abdominal surgery. However, the concentrations in groups Oc, IM, and Oc + IM on postoperative days 7 and 14 were markedly lower than those in groups C and NS ( P < 0.05). The wound strength was significantly greater on day 14 than on day 7 in all groups.

CONCLUSIONS

In the rats with octreotide irrigation, the EGF-R level was decreased, the plasma tPA concentration was higher, and the plasma PAI-1 and PAI-2 concentrations were lower when compared with values in group C and group NS rats on days 7 and 14 after surgery. The data suggest that EGF-R, tPA, PAI-1, and PAI-2 are all involved in the mechanism of octreotide's action in reducing adhesion formation.

The role of gelatinase in hepatic metastasis of colorectal cancer

PURPOSE

To determine the role of gelatinase in the hepatic metastatic process of colorectal cancer, we correlated gelatinolytic activity in colorectal tumor tissue both to the presence of intravasated colorectal epithelial cells and to the formation of liver metastasis.

EXPERIMENTAL DESIGN

The gelatinolytic activity was analyzed in tumor tissue samples from 68 colorectal cancer patients by using gelatin substrate zymography. The presence of intravasated colorectal epithelial cells was defined as detection of guanylyl cyclase C mRNA in blood sampled from drainage vein of a tumor-bearing colorectal segment.

RESULTS

Forty of 68 patients were noted to have guanylyl cyclase C mRNA expression in their drainage venous blood. Fifteen patients were noted to have liver metastasis at the time of surgery, and another 15 patients developed liver metastasis during median follow-up period of 53 months. Either individual or total gelatinolytic activity in colorectal tumor tissue failed to predict the presence of intravasated colorectal epithelial cells in the drainage venous blood or formation of liver metastasis. Presence of both intravasated colorectal epithelial cells and high total gelatinolytic activity in colorectal tumor tissue, however, is a strong predictor of liver metastasis (P = 0.004).

CONCLUSION

Our data suggested that gelatinolytic activity in colorectal tumor tissues may facilitate the hepatic metastatic process in the steps after intravasation but not during or before intravasation.

Electrically deactivating nearest-neighbor donor-pair defects in Si

Based on first-principles density-functional calculations, we propose a class of nearest-neighbor donor pairs that are energetically favorable in highly n-type Si. These donor pairs comprise dopant atoms either fourfold coordinated at the nearest-neighbor distance or threefold coordinated through bond-breaking relaxations. For P and As dopants, the two defect states are very close in energy, less than 0.1 eV, while the threefold coordinated state is more stable by 0.24 eV for Sb dopants. The former state has a very deep donor level close to the valence band maximum, while the defect level lies deep inside the valence band for the latter. Thus, both the donor pairs are electrically inactive at very high doping levels, and they are suggested to be responsible for the observed saturation of carriers.

The effect of an intestinal ischemia-reperfusion injury on renal nerve activity among rats

An intestinal ischemia-reperfusion injury (IIR) may induce renal tubular dysfunction and a reduction in renal blood flow that may be related to the alteration of renal-nerve activity. A rat model of IIR injury was established. The superior mesenteric artery was clamped for 120 min, constituting the ischemic period, and was then released for 60 min, thus constituting the reperfusion period. Renal-nerve activity, renal function, and hemodynamic changes were recorded during the different periods. The levels of calcitonin gene-related peptide (CGRP) in portal-vein blood and intestinal tissue were investigated here. In the reperfusion period, the efferent renal-nerve activity (ERNA) was markedly elevated (94.3% +/- 21.6% higher than the baseline value), such an elevation being only partially reversed by fluid expansion (29.3% +/- 5.2% higher than the baseline value). The elevation of ERNA contributed to the renal blood-flow reduction from 6.8 +/- 0.3 mL/min/g to 2.0 +/- 0.4 mL/min/g, and decreased diuretic and natriuretic responses. The afferent renal nerve activity (ARNA) was markedly depressed (45.7% +/- 8.1% lower than the baseline value) during the reperfusion period. This depression was not reversed by fluid expansion, suggesting that the baroreflex was not responsible for this effect. The blunted ARNA also contributed to the elevation of ERNA by way of a renorenal reflex. The potent vasodilator neuropeptide in the gut, CGRP, revealed an increased level in the portal-vein blood (92.2 +/- 4.4 pg/mL vs. 57.8 +/- 0.6 pg/mL) and also in intestinal tissue (655.8 +/- 115.9 pg/mL vs. 60.5 +/- 9.4 pg/mL) with a time-matched related pattern with the change to renal-nerve activity, suggesting CGRP's role regarding changes in renal-nerve activity. This study indicates that the elevated ERNA level associated with IIR injury is related to a systemic hypotension-induced baroreflex, the contra-lateral inhibition of ARNA, and possibly also gut-released CGRP. In regards to an IIR injury, the depressed ARNA reflects the involvement of a renal sensory- impairment mechanism.

Dynamics of fullerene coalescence

Fullerene coalescence experimentally found in fullerene-embedded single-wall nanotubes under electron-beam irradiation or heat treatment is simulated by minimizing the classical action for many atom systems. The dynamical trajectory for forming a (5,5) C120 nanocapsule from two C60 fullerene molecules consists of thermal motions around potential basins and ten successive Stone-Wales-type bond rotations after the initial cage-opening process for which energy cost is about 8 eV. Dynamical paths for forming large-diameter nanocapsules with (10,0), (6,6), and (12,0) chiral indexes have more bond rotations than 25 with the transition barriers in a range of 10-12 eV.

Comparison of medial-to-lateral versus traditional lateral-to-medial laparoscopic dissection sequences for resection of rectosigmoid cancers: randomized controlled clinical trial

This study aimed to compare medial-to-lateral versus lateral-to-medial laparoscopic dissection sequences for resecting rectosigmoid cancers. We hypothesized that the medial-to-lateral approach was a more efficient procedure and with potentially better oncologic results. Between January 1997 and June 1999, a total of 67 patients of rectosigmoid cancer treated by one surgeon using the laparoscopic approach were recruited for this prospective, randomized, double-blind clinical trial. Using the blocked randomization method, 36 patients were allocated to a medial-to-lateral (M) group and the other 31 to a lateral-to-medial (L) group; the groups were well matched in age, gender, symptoms, body mass index, American Society of Anesthesiology (ASA) class, tumor location, tumor distance above the anal verge, tumor gross morphology, TNM stage of the tumor, and accuracy of preoperative TNM staging (p > 0.05). All patients were followed up until June 2001. We found that the M group had a significantly shorter operating time and lower overall costs than the L group (p < 0.05). There was no significant difference between these two groups in terms of intraoperative complications, conversion rate, postoperative ileus, hospitalization, postoperative pain, postoperative complications, wound length, or disability (p > 0.05). The postoperative proinflammatory response, evaluated by the C-reactive protein level and the erythrocyte sedimentation rate, was significantly lower in the M group (p < 0.05). There was no significant difference between these two groups regarding postoperative immunosuppression, as evaluated by the alterations of total lymphocyte counts and the CD4(+)/CD8(+) ratio (p > 0.05). The extent of dissection of these two dissection approaches was similar, as the harvested lymph nodes were equivalent (p > 0.05). During the whole follow-up period (median 32 months, range 24-54 months), the tumor recurrence rate was similar for these two groups of patients (5.6% in the M group vs. 6.5% in the L group; p > 0.05). These findings indicated that the medial-to-lateral approach was quicker, less expensive and possibly less invasive; moreover, it gave oncologic results similar to those achieved with the traditional lateral-to-medial dissection sequence. We thus concluded that the medial-to-lateral dissection sequence may currently be the most appropriate procedure for laparoscopic resection of rectosigmoid cancers.

Spectral correlation in incommensurate multiwalled carbon nanotubes

We investigate the energy spectra of clean incommensurate double-walled carbon nanotubes, and find that the overall spectral properties are described by the critical statistics similar to that known in the Anderson metal-insulator transition. In the energy spectra, there exist three different regimes characterized by Wigner-Dyson, Poisson, and semi-Poisson distributions. This feature implies that the electron transport in incommensurate multiwalled nanotubes can be either diffusive, ballistic, or intermediate between them, depending on the position of the Fermi energy.

Quality of life of breast cancer patients in Taiwan: Validation of the Taiwan Chinese version of the EORTC QLQ-C30 and EORTC QLQ-BR23

The objective of this study was to test the reliability and validity of the Taiwan Chinese version of the EORTC QLQ-C30 (version 3) and EORTC QLQ-BR23. The authors followed the guidelines of translation and pilot testing of the questionnaires. The questionnaires were given to 35 breast cancer patients under active treatment and 54 under follow-up at the National Taiwan University Hospital from November 2000 to October 2001. A retest was conducted one to two weeks after the first interview/form completion for the follow-up group. The intraclass correlation coefficients of the two questionnaires were moderate to high in the follow-up group. The Cronbach's alpha coefficients of most scales of the two questionnaires were > or = 0.70 except that of physical functioning (0.68), cognitive functioning (0.53), and arm symptoms (0.59). Correlations of scales measuring similar dimensions of the EORTC QLQ-C30 and the SF-36 were moderate. Patients in the active treatment group had more serious QOL problems due to disease and treatment. Results of this study showed that the Taiwan Chinese version of the two questionnaires had good test/retest reliability, high internal consistency in most scales, and could show the expected differences between patients in active chemotherapy and follow-up group.

Establishment and characterization of a rectal cancer model in mice: application to cytokine gene therapy

BACKGROUND AND AIMS

We established an orthotopic animal model of rectal cancer in mice and applied this model to the study of the antitumor effects of cytokine-assisted tumor vaccine.

MATERIALS AND METHODS

The CT-26 murine colon adenocarcinoma cells were inoculated into the submucosa of the rectum of the mice to induce the rectal tumor. The tumor growth rate and the survival time of the mice were observed. The cDNA of granulocyte-macrophage colony-stimulating factor (GM-CSF) was transduced to the CT-26 cell line via a retroviral vector, and the therapeutic effects of irradiated GM-CSF secreting tumor vaccine on the rectal tumor were investigated.

RESULTS

All the mice implanted with the wild-type tumor cells had tumor growth in the rectum and died. The mean survival time of the mice was 28.9 days. Two doses of irradiated GM-CSF secreting tumor vaccine administered on days 0 and 3 after tumor cell implantation significantly prolonged the survival of the mice with rectal tumor compared with that of the control groups ( P<0.0001). In contrast, no antitumor effect was observed when the treatment with GM-CSF secreting tumor vaccine was delayed to 3 days after tumor cell implantation ( P>0.17).

CONCLUSION

The results suggest that cytokine gene therapy exerts an antitumor effect on small tumors and may be considered as an adjuvant immunotherapy of rectal cancers and prevention of reimplantation of tumor cells disseminated during or following surgery. The orthotopic animal model of the rectal cancer in mice could be applied to the in vivo experimental studies of rectal cancer.

Association of proline-directed protein kinase FA with tumorigenesis, invasion, and poor prognosis of human colon carcinoma

BACKGROUND

Initial studies revealed that the multisubstrate proline-directed protein kinase F(A) (PDPK F(A)) is overexpressed in various types of human carcinomas relative to normal controls. Suppression of overexpressed PDPK F(A) inhibits the growth of cancer cells, suggesting a role of this PDPK in human malignancy. In this study, we combine immunohistologic, molecular, cellular, animal, and clinicopathologic studies to demonstrate an essential and critical role of PDPK F(A) in progression and poor prognosis of human colon carcinoma.

METHODS

The stable antisense clones of human colon carcinoma cells with specific suppression of PDPK F(A) were established for tumorigenesis and invasion studies. In immunohistologic and clinicopathologic studies, the expression and localization of PDPK F(A) were analyzed by immunohistochemical staining of the specimens obtained from human colon carcinoma patients with Dukes Stage B/C.

RESULTS

Initial molecular and cellular studies revealed that the antisense clone of colon carcinoma cells (COLO-205) with specific suppression of PDPK F(A) dramatically lost capabilities of adhesion, chemotaxis, and invasion when compared with the parental or control-transfected colon carcinoma cells. This is the first indication of an association of overexpressed PDPK F(A) with colon carcinoma progression. In agreement with this notion, the in vivo study also revealed that the mice injected with the antisense clone with low-level PDPK F(A) only developed very small tumors (< 0.5 cm(3)) even after a 6-week observation. This is in contrast to the parental or control-transfected cells that developed large tumors (> 5 cm(3)) under identical conditions. Pathologic evaluation revealed invasion to the muscle layer in all tumors formed by the parental cells. In contrast, there was no sign of invasion in mice injected with the antisense clone, confirming an essential role of PDPK F(A) in colon carcinoma progression. Clinicopathologic study also revealed that PDPK F(A) is preferentially overexpressed in the invasive area of colon carcinomatous tissues and overexpression of PDPK F(A) is statistically and closely correlated with venous/lymphatic infiltration, lymph node metastasis, and poor prognosis of colon carcinoma patients with Dukes Stage B/C.

CONCLUSIONS

The results demonstrate an essential and critical role of overexpressed PDPK F(A) in progression and poor prognosis of colon carcinoma patients. Suppression of overexpressed PDPK F(A) may provide a new powerful adjuvant approach to prevent human colon carcinoma progression and poor prognosis after surgery and chemotherapy.

High-frequency microsatellite instability predicts better chemosensitivity to high-dose 5-fluorouracil plus leucovorin chemotherapy for stage IV sporadic colorectal cancer after palliative bowel resection

The influence of MSI on treatment outcome of colorectal cancers remains unclear and deserves further investigation. We recruited 244 patients with stage IV sporadic colorectal cancers for our study, based on appropriate eligibility criteria. Patients were nonrandomly allocated to 2 treatment groups of either with or without high-dose 5-FU plus leucovorin chemotherapy (HDFL, 5-FU 2,600 mg/m(2) leucovorin 300 mg/m(2) maximum 500 mg). Each treatment group was further divided into 2 subgroups according to high-frequency MSI (MSI-H) status. MSI-H was defined as the appearance of MSI in at least 2 of the 5 examined chromosomal loci (BAT-25, BAT-26, D5S346, D2S123, D17S250). We compared clinicopathologic parameters, p53 overexpression and overall survival between the groups. In addition, 4 subgroups were identified as follows: MSI-H(+)HDFL(+), n = 35; MSI-H(-)HDFL(+), n = 134; MSI-H(+)HDFL(-), n = 17; MSI-H(-)HDFL(-), n = 58. There was no significant difference of background clinicopathologic data between the HDFL(+) and HDFL(-) treatment groups (p > 0.05). Survival analyses indicated that the patients of subgroup MSI-H(+)HDFL(+) survived significantly longer than those of subgroup MSI-H(-)HDFL(+), with median survival times of 24 (95% CI 20.2-27.9) and 13 (95% CI 11.6-14.4) months, respectively (p = 0.0001, log-rank test). In contrast, in patients without chemotherapy, the prognosis was poor irrespective of MSI status, with median survival times of 7.0 (95% CI 4.6-9.4) and 7.0 (95% CI 6.1-7.9) months in the MSI-H(+)HDFL(-) and MSI-H(-)HDFL(-) subgroups, respectively (p = 0.8205, log-rank test). MSI-H cancers responded significantly better to HDFL (p = 0.001), with a mean response rate of 65.71% (95% CI 49.98-81.44%) in subgroup MSI-H(+)HDFL(+) compared to 35.07% (95% CI 26.99-43.15%) in subgroup MSI-H(-)HDFL(+). There appeared to be no preferential metastatic site where response to HDFL can be predicted based on the MSI status of the primary tumor. Toxicity to HDFL was similarly minimal between MSI-H(+) and MSI-H(-) patients (p > 0.05). Multivariate analysis of all patients further indicated that MSI-H and chemotherapy were independent favorable prognostic parameters (p < 0.05). Thus, the better prognosis of stage IV sporadic colorectal cancers with MSI-H may be associated with better chemosensitivity, rather than lower aggressiveness in biologic behavior.

Association of overexpressed proline-directed protein kinase F(A) with chemoresistance, invasion, and recurrence in patients with bladder carcinoma

BACKGROUND

It has been shown previously that proline-directed protein kinase F(A) (PDPK F(A)) is overexpressed in various human malignancies compared with its expression in normal controls, and the suppression of overexpressed PDPK F(A) is capable of inhibiting the growth of various types of human carcinoma cells, suggesting a role for this PDPK in human malignancies. In this report, the authors combine immunohistologic, molecular, cellular, and clinicopathologic studies to demonstrate further an essential critical role for overexpressed PDPK F(A) in bladder carcinoma invasion, chemoresistance, and poor prognosis.

METHODS

The expression and localization of PDPK F(A) were analyzed by the immunohistochemical staining of specimens obtained from patients with primary transitional cell carcinoma (TCC) of the bladder. The stable antisense clones of human bladder carcinoma cells with specific suppression of overexpressed PDPK F(A) were established for invasion and chemosensitivity studies.

RESULTS

The immunohistochemical study revealed that PDPK F(A) was overexpressed preferentially in the invasive bladder carcinoma tissues. It was found that the stable antisense clones with specific suppression of overexpressed PDPK F(A) to approximately 40% of the parental control level were capable of inhibiting the invasive activity and simultaneously enhancing the chemosensitivity of bladder carcinoma cells to various therapeutic drugs, such as vinblastine, vincristine, paclitaxel, and bleomycin. Clinicopathologic studies also revealed a correlation between overexpressed PDPK F(A) and disease recurrence/survival in patients with primary TCC (P < 0.05).

CONCLUSIONS

Taken together, the results demonstrate an essential critical role of overexpressed PDPK F(A) in invasion, chemoresistance, and poor prognosis. Suppression of overexpressed PDPK F(A) may provide a new potential target for therapeutic intervention aimed at preventing chemoresistance, disease progression, and recurrence in patients with bladder carcinoma.

Selective use of ultrasonography for the detection of pneumoperitoneum

OBJECTIVE

Whether ultrasonography is superior to plain radiography for the detection of pneumoperitoneum is unknown. The goal of this study was to determine the value of ultrasonography for the detection of pneumoperitoneum.

METHODS

One hundred thirty-two patients with suspected hollow-organ perforation were prospectively selected for study. All 132 patients received ultrasonography, upright chest radiography, and left lateral decubitus abdominal radiography examinations. The diagnostic accuracies of chest and abdominal radiographs for the detection of pneumoperitoneum were compared with corresponding values from ultrasonography.

RESULTS

Of the 125 patients who underwent laparotomy, 121 patients had hollow-organ perforation, three patients had perforated appendicitis, and one patient had acute cholecystitis. For the diagnosis of pneumoperitoneum, ultrasonography demonstrated a sensitivity of 93%, a specificity of 64%, a positive predictive value of 97%, a negative predictive value of 44%, and an accuracy of 90%. Plain radiography revealed a sensitivity of 79%, a specificity of 64%, a positive predictive value of 96%, a negative predictive value of 21%, and an accuracy of 77%.

CONCLUSIONS

Ultrasonography is a more sensitive diagnosing modality than plain radiography for the diagnosis of pneumoperitoneum. The authors suggest that ultrasonography was a useful diagnostic modality when plain radiographs failed to reveal pneumoperitoneum among patients with suspected hollow-organ perforation.

Silicone migration from silicone-injected breasts: magnetic resonance images

Injection of liquid silicone into the breast was performed illicitly in the 1950s to 1960s and was subsequently prohibited. Many complications arise from silicone injection, and liquid silicone migration is a complication that has not been widely reported. The authors present magnetic resonance images of a patient with liquid silicone migration from the breast to the upper chest and lower neck. Breast ultrasonographic and mammographic findings are also presented for correlation.

Association of color Doppler vascularity index and microvessel density with survival in patients with gastric cancer

OBJECTIVE

The purpose of this study was to investigate the clinical usefulness of microvessel density (MVD) and an in vivo angiogenesis parameter, color Doppler vascularity index (CDVI), in patients with gastric cancer.

SUMMARY BACKGROUND DATA

Many studies have reported a significant association between the degree of MVD-evaluated angiogenesis with the clinicopathologic factors and prognosis of patients with various solid tumors. All these studies were accomplished on tissue sections retrospectively obtained from surgical specimens. However, an in vivo method to assess tumor angiogenesis for human malignancies is highly desirable for diagnostic purpose, treatment planning, and follow-up. The CDVI is a new ultrasound parameter for evaluating in vivo angiogenesis, has a good correlation with status of lymph node metastasis in cervical carcinoma, and can predict distant metastasis and survival in colon cancer patients. Therefore, the CDVI may also be useful to assess in vivo angiogenesis in human gastric cancer.

METHODS

A total of 79 patients with gastric cancer were enrolled in this study, and microvessel density was evaluated by using immunohistochemical staining of surgical specimens with anti-CD-34 antibody. Tumors were sonographically visible in 31 patients. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section, and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). Correlation between MVD, CDVI and clinicopathologic factors and patient survival was studied.

RESULTS

The MVD was significantly correlated with vascular invasion by multiple linear regression analysis. Although the survival of patients with high MVD (> 32) was significantly worse than those with low MVD (< 32) by univariate analysis, vascular invasion was an independent prognostic factor by Cox proportional hazard model. There was a linear correlation between CDVI and MVD (r =.495, P =.005). Moreover, in patients with a high CDVI (> 11%), the survival rate was significantly lower than that in those with low CDVI (< or = 11%, P =.005). None of the patients with high CDVI (> 11%) survived 2 years after curative resection. In addition to vascular invasion, the CDVI was another independent prognostic factor in the patients with stage III gastric cancer.

CONCLUSIONS

Vascular invasion was an important prognostic indicator in gastric cancer. The high CDVI was a good preoperative indicator of early death in stage III gastric cancer patients. Thus, the CDVI may be helpful in selecting patients with gastric cancer for neoadjuvant chemotherapy and/or anti-angiogenic therapy.

Seasonal prevalence of anti-Japanese encephalitis virus antibody in pigs in different regions of Taiwan

Although the endemic season of Japanese encephalitis lasts from May through October, sporadic cases occur in other months of the year. To appreciate the real situation of Japanese encephalitis virus (JEV) activity throughout the year, a survey was conducted using hemagglutination-inhibition test to detect the presence of anti-JEV antibodies in pigs' sera, which were collected from 4 regions of Taiwan between January 2000 and January 2001. Results indicate that (1) JEV-infected pigs were found throughout the year; (2) the prevalence rates of JEV in the 4 regions in descending order were 70% in Miaoli, 59% in Hualien, 52% in Pingtung, and 49% in Nantou; (3) similar to that in 1990, the peak endemic months appeared 1 month after the date of 50% seroconversion (May 21, 2000); (4) infected pigs were present during the period from December through April as a reservoir for over-wintering of JEV; and (5) there was a suggestive evidence for the occurrence of sporadic cases of JEV during the December-April period. In conclusion, JEV propagates and is active indigenously in the winter as well as other seasons of the year.

Prospective evaluation of laparoscopy-assisted colectomy versus laparotomy with resection for management of complex polyps of the sigmoid colon

Laparoscopy-assisted colectomy is technically feasible, but objective evidence of its benefits remains scarce. This study was done to evaluate the outcomes and operative stress of laparoscopy-assisted colectomy versus the traditional open method in the management of sigmoid complex polyps that cannot be safely or adequately removed by colonofibroscopy. Between January 1997 and December 1999, a total of 42 patients were equally randomized to the laparoscopy group and the laparotomy group by the blocked randomization method. Three patients randomized to the laparoscopy group did not complete the trial; therefore 18 patients treated by laparoscopy-assisted sigmoidectomy and the other 21 treated by the open method were prospectively evaluated. These two groups of patients were well matched in age, gender, symptoms, tumor location, localization method, tumor size, morphology, histopathology, and the accuracy of the clinical diagnosis. Two standardized surgical strategies, the lateral-to-medial and medial-to-lateral dissection sequences, were performed in 14 and 4 patients of the laparoscopy group, respectively, according to whether their tumors were located above or below 20 cm above the anal verge. After evaluating the surgical outcomes, we found that the laparoscopy group was significantly better than the laparotomy group in regard to parameters that included severity of postoperative pain, wound size, postoperative complication rate, and the duration of postoperative ileus, hospitalization, and disability. There was no significant difference in the operating times for these two groups. However, the costs of the laparoscopy group were significantly higher. To evaluate the surgical stress, we measured the serum C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), total lymphocyte count, and CD4+/CD8+ ratio 24 hours before and after surgery. We found that the postoperative serum CRP level and the ESR were significantly less elevated and the total lymphocyte counts and CD4+/CD8+ ratio were significantly less depressed in the laparoscopy group than in the laparotomy group. We thus concluded that laparoscopy-assisted sigmoidectomy can be safely performed with shorter convalescence and less operative stress but at a higher cost. We strongly recommended the use of this technique in the management of sigmoid complex polyps if the patient's economic status permits.

P53 overexpression predicts poor chemosensitivity to high-dose 5-fluorouracil plus leucovorin chemotherapy for stage IV colorectal cancers after palliative bowel resection

Our study aims to further clarify the prognostic significance of p53 overexpression in stage IV colorectal cancer. Between January 1994 and June 1997, we recruited 144 patients with stage IV colorectal cancers for our study, based on appropriate eligibility criteria. The patients were nonrandomly allocated to 2 treatment groups of either with or without high-dose 5-fluorouracil plus leucovorin chemotherapy (HDFL: 5-Fu: 2,600 mg/m(2) leucovorin 300 mg/m maximum 500 mg). Each treatment group was further divided into 2 subgroups according to the status of p53 overexpression. Therefore, 4 subgroups were allocated in our study and were designated as p53 (overexpression) HDFL (+), n = 65; p53 (normal) HDFL (+), n = 37; p53 (overexpression) HDFL (-), n = 27; and p53 (normal) HDFL (-), n = 15, respectively. All patients were prospectively followed until April 2001. There was no significant difference of the background clinicopathologic data of these 4 allocated subgroups of patients (p > 0.05). Multivariate analysis of various clinicopathologic factors of the whole group of patients indicated that age > or = 60 years, poor differentiation, mucin production, CEA > 100 ng/ml, p53 overexpression and without chemotherapy were the significant independent poor prognostic factors (p < 0.05). Survival analyses indicated that the patients of subgroup p53 (normal) HDFL (+) survived significantly longer than those of subgroup p53 (overexpression) HDFL (+), with mean survival time (95% confidence interval [CI]) of 20.24 (16.24-24.25) and 13.29 (10.98-15.60) months, respectively (p = 0.0043, log-rank test). In contrast, in patients without chemotherapy, the prognosis was poor regardless of their p53 status, with mean survival time (95% CI) of 6.85 (5.47-8.23) and 5.87 (4.48-7.26) months in p53 (overexpression) HDFL (-) and p53 (normal) HDFL (-) subgroups of patients, respectively (p = 0.2820, log-rank test). Cancers of normal p53 expression responded significantly better to HDFL (p < 0.05), with mean response rate (95% CI) being 65.57% (52.18-82.96%) in subgroup p53 (normal) HDFL (+) as compared to 35.38% (23.52-47.24%) in subgroup p53 (overexpression) HDFL (+). The toxicity to HDFL was similarly minimal between p53-normal and p53-overexpression patients (p > 0.05). We thus concluded that the poorer prognosis of stage IV colorectal cancers with p53 overexpression was associated with their poorer chemosensitivity rather than the more biologic aggressiveness.

Magnetic resonance imaging characteristics of paraffinomas and siliconomas after mammoplasty

BACKGROUND AND PURPOSE

Breast paraffinomas and siliconomas are granulomas caused by tissue reaction to paraffin oil and silicone injection after mammoplasty. These granulomas usually present as multiple hard masses that mimic breast cancer. Mammography and sonography have only a limited role in differentiating these masses. Magnetic resonance (MR) imaging findings of these granulomas have rarely been reported. This study evaluated the MR imaging manifestations of these granulomas.

MATERIALS AND METHODS

MR imaging, mammography, and sonography were used to examine 58 breasts in 29 women with breast lumps who had undergone mammoplasty with injections of paraffin oil (n = 8) or liquid silicone (n = 50). The protocol included T1-weighted images (T1WI), fat-suppressed (FS) T2WI, post-contrast FS three-dimensional fast dynamic sequences, and FS T1WI.

RESULTS

Deep structures of the 58 breasts could not be clearly evaluated by sonography or mammography. Two types of MR imaging characteristics were identified: type I lesions were hypointense on T2WI and type II lesions had mixed hypointense and hyperintense components on T2WI. Both showed intermediate intensity on T1WI and revealed no enhancement on post-contrast dynamic sequences and FS T1WI. Type II lesions were seen only in siliconomas. Mastectomy was performed on seven breasts and paraffinomas or siliconomas were confirmed by pathology. When correlating MR images with pathology, hypointense lesions on T2WI in both type I and II lesions were foreign body granulomas with fibrosis and calcification. Hyperintense lesions on T2WI in type II were liquid silicone. A case of infiltrating ductal carcinoma was found in one breast in which MR imaging was successful in identifying the strongly enhanced solitary tumor from a background of type I lesions of paraffinomas preoperatively. Of the 51 breasts that did not receive surgery, no breast cancers were detected clinically or by follow-up imaging after a median of 27 months (19-54 mo).

CONCLUSIONS

Breast paraffinomas and siliconomas after mammoplasty have specific MR findings that are distinct from those of breast cancers. MR imaging is superior to sonography and mammography in the evaluation of breast paraffinomas and siliconomas.

Laparoscopic Ladd's procedure for intestinal malrotation: report of three cases

Ladd's procedure for laparoscopic repair of malrotation has many advantages over conventional surgical techniques, such as earlier feeding and discharge. However, this procedure is still not commonly used in Taiwan. This report describes the results of treatment of intestinal malrotation in three patients using laparoscopic Ladd's procedure. The patients, aged 8 days, 17 days, and 3 years, underwent laparoscopic Ladd's procedure between July 1999 and September 2000. All three patients had symptoms of intermittent vomiting and were shown to have intestinal malrotation by upper gastrointestinal series study. The procedure was performed using three trocars of 5 mm diameter placed at the infraumbilical ring and the right and left lower quadrants. All procedures were completed laparoscopically. The operative times were 4.8, 3.6, and 3.5 hours, respectively. Feeding was started on postoperative Day 2 to 5, and the hospital stay was 6 to 11 days. Our results suggest that laparoscopic Ladd's procedure can be performed safely in pediatric patients. In addition, patients are expected to benefit from the smaller incision, earlier feeding, shorter hospital stay, and fewer complications compared with traditional Ladd's procedure.

Calcium concentration in rat liver mitochondria during anoxic incubation

BACKGROUND AND PURPOSE

The impairment of mitochondrial respiratory function is an important problem in anoxia-reoxygenation injury in animal cells. This study investigated the role of mitochondrial calcium ions (Ca2+) in a model of anoxic incubation in isolated rat liver mitochondria.

METHODS

Mitochondria isolated from Wistar rat liver were subjected to anoxic incubation for 5 to 60 minutes. Changes in oxygen consumption by anoxic mitochondria were recorded using polarography. Changes in NAD(P)H fluorescence were recorded simultaneously. Intramitochondrial matrix free calcium concentration ([Ca2+]) was measured using the fluo-3/AM loading method. Respiratory function in anoxic mitochondria was measured polarographically from oxygen consumption.

RESULTS

Mitochondrial state 3 respiration decreased progressively with increased duration of anoxic incubation, while state 4 respiration increased progressively. The decrease in the ADP/O ratio with the duration of anoxic incubation indicated that the efficiency of oxidative phosphorylation decreased with increased duration of anoxia. As the duration of anoxic incubation increased, the amplitude and rapidity of the oxido-reduction change in NAD(P)H fluorescence decreased. The respiratory control ratio showed that the functional integrity of mitochondria was linearly correlated with the free [Ca2+] in mitochondrial matrix (r2 = 0.977) and the total calcium concentration (r2 = 0.934). The free [Ca2+] in mitochondrial matrix significantly decreased with increasing anoxic duration. Total mitochondrial calcium concentration also decreased with increasing anoxic duration (p < 0.01).

CONCLUSIONS

The supply of NADH was reduced during anoxic incubation of isolated rat hepatocyte mitochondria, which resulted in impairment of mitochondrial respiratory function. The decrease in free [Ca2+] in the mitochondrial matrix with increased duration of anoxic incubation implies that calcium ions may be released into the cytosol during anoxia.

Prognostic factors for the survival of Taiwanese breast cancer patients

BACKGROUND

The incidence of breast cancer is increasing rapidly in Taiwan. Prognostic factors for survival in Taiwanese breast cancer patients have not been comprehensively studied.

METHODS

Registry records of 979 newly diagnosed breast cancer patients who received initial therapy at National Taiwan University Hospital from January 1991 to December 1995 were linked to the national mortality file from 1991 to 1997 using the citizen ID of each patient. The effects of potential prognostic factors were assessed using Cox's regression model. Five-year survival rates of common characteristics were predicted according to the model.

RESULTS

Among the 979 patients, 174 died within the 7-year study period (163 died from breast cancer). The overall 5-year survival rate was 81% (95% confidence interval, CI = 78-84%). The adjusted hazard ratio (HR) of mortality for patients aged at least 50 years versus patients aged less than 50 years was 1.49 (95% CI = 1.08-2.05); the HR of mortality for tumors of at least 5 cm in diameter versus those less than 2 cm was 2.45 (95% CI = 1.33-4.51); the HR of mortality for positive versus negative nodes was 3.65 (95% CI = 2.33-5.71); and the HR of mortality for pathology of infiltrating ductal carcinoma versus other types was 2.63 (95% CI = 1.32-5.27). Five-year survival rates for patients without node involvement were higher than 90% regardless of tumor size, while those for patients with positive nodes were significantly lower, except for patients with tumors of less than 2 cm in diameter.

CONCLUSIONS

Patients who had a small tumor and involvement of fewer nodes, and who were younger, had a higher probability of survival. Node involvement was more important than tumor size in the prediction of survival.

Effect of taurine and beta-alanine on morphological changes of pancreas in streptozotocin-induced rats

In order to determine the effects of taurine supplementation or depletion on the morphological changes of pancreatic beta-cells in streptozotocin-induced diabetic rats, Sprague-Dawley male rats were fed the purified diets supplemented with 1, 2 or 3% taurine or 5% beta-alanine in their drinking water for 7 weeks. After 3 weeks, diabetes was induced by streptozotocin injection (50 mg/kg body-weight). Pancreatic morphology was observed by transmission electron microscopy. The pancreatic beta-cell of the non-diabetic (CO) group had the many secretory granules, rough endoplasmic reticulum and rod shaped mitochondria. However, the beta-cells of non taurine-supplemented diabetic (EO) group were severely damaged, showing depleted secretory granules. In the 1% taurine-supplemented diabetic group, the beta-cells were less damaged compared to the EO group and had some apparently normal secretory granules, but most of rough endoplasmic reticulum and mitochondria was destroyed. The beta-cell of 2% taurine-supplemented diabetic group had swollen rough endoplasmic reticulum, round-shaped mitochondria and some apparently normal secretory granules. The beta-cell of 3% taurine-supplemented diabetic group was little different from that of non-diabetic group. The pancreatic beta-cell of taurine-depleted diabetic group was not destroyed but had many small secretory granules which appeared immature. This was reflected in the blood glucose concentrations of this group. Therefore, taurine may prevent insulin-dependent diabetes by protection of the pancreatic beta-cell and may also preserve normal secretory granules. From these results, taurine supplementation may be recommended for prevention and treatment of diabetes.

Immunohistochemical localization of insulin in pancreatic beta-cells of taurine-supplemented or taurine-depleted diabetic rats

The purpose of this study was to observe the effects of taurine supplementation or depletion on the immunohistochemical localization of insulin in pancreas of streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were fed for 7 weeks with a purified diet that was supplemented with 0, 1, 2 or 3% taurine in their drinking water. To induce taurine depletion, rats were treated with 5% beta-alanine in their drinking water. After 3 weeks, diabetes was induced by streptozotocin injection (50 mg/kg body-weight). The pancreatic tissue was stained immunocytochemically, using an antibody to insulin, and examined by light microscopy. The insulin levels in pancreatic beta-cells of the diabetic group that received no taurine-supplement were significantly decreased, compared to the non-diabetic group. The levels of insulin in beta-cell of 1% and 2% taurine-supplemented diabetic groups were significantly higher than those of the diabetic group, whereas the levels in the group receiving 3% taurine were not significantly different from that of non-diabetic rats. Therefore, it may be suggested that taurine protect pancreatic beta-cells against destruction by ptozotocin injection in a dose-dependent way.

Simultaneous detection of colonic epithelial cells in portal venous and peripheral blood during colorectal cancer surgery

PURPOSE

This study was designed to show, in certain patients, that colonic epithelial cells can be present in peripheral blood while absent in portal venous blood.

METHODS

The circulating colorectal epithelial cells were detected by a reverse transcriptase-polymerase chain reaction assay, which involved amplifying guanylyl cyclase C transcripts. Portal venous and peripheral blood samples were obtained at intervals from 58 patients undergoing colorectal cancer surgery.

RESULTS

Circulating colonic epithelial cells were more frequently detected in portal venous blood than in peripheral blood only before mobilization of the tumor-bearing colon segment in patients with tumors of Stage B. In five other patients, before mobilization of their tumor-bearing colon segments, and in another three patients, during the mobilization, colorectal epithelial cells were detected in peripheral blood but not in portal venous blood. These eight patients had Stage C or D tumors.

CONCLUSION

In 8 of 58 patients, colorectal epithelial cells were detected in peripheral but not in portal venous blood. Metastatic deposits in lymphatic vessels or liver might be the source of these cells.

IL-6 inhibits apoptosis and retains oxidative DNA lesions in human gastric cancer AGS cells through up-regulation of anti-apoptotic gene mcl-1

Apoptosis plays a critical role in maintaining genomic integrity by selectively removing the most heavily damaged cells from the population. Reactive oxygen species (ROS) and certain inflammatory cytokines are always elevated during the human carcinogenic process. However, the biological significance of the interplay between ROS and inflammatory cytokine remains elusive. This study demonstrates that interleukin-6 (IL-6) effectively protects gastric cancer cells from the apoptosis induced by hydrogen peroxide (H(2)O(2)). The cell death signaling JNK pathway elicited by H(2)O(2) is also inhibited by IL-6. We further found that Mcl-1, but not other Bcl-2 family members, was up-regulated by IL-6, by a substantial level over 24 h. We further transfected a mcl-1 expression vector, pCMV-mcl-1, into the AGS cells, and successfully obtained several mcl-1-overexpressing clones. Flow cytometric analysis shows that these mcl-1-overexpressing AGS cells are more resistant to the apoptosis induced by H(2)O(2) when compared with the neo control AGS cells. Consistently, the activation of the JNK pathway induced by H(2)O(2) is also blocked in mcl-1-overexpressed cells. These results indicate that the anti-apoptotic effect of IL-6 is, at least in part, due to the up-regulation of mcl-1. To our surprise, either IL-6 exposure or mcl-1 overexpression fails to reduce the level of intracellular peroxides in the AGS cells triggered by H(2)O(2). This study also determined the level of 8-hydroxydeoxyguanosine (8-OH-dGua), an indicator for oxidative DNA lesions in IL-6-treated or mcl-1-overexpressed AGS cells after treatment with H(2)O(2). Notably, our results indicate that a majority of the 8-OH-dGua is efficiently removed in the AGS cells without IL-6 treatment, whereas only approximately 50% of the 8-OH-dGua was repaired in the IL-6-treated AGS cells after 24 h. Similarly, approximately 60-70% of the 8-OH-dGua also failed to repair and was retained in the genomic DNA of the mcl-1 transfectants. Results in this study provide a novel mechanism by which up-regulation of the Mcl-1 protein by IL-6 may enhance the susceptibility to H(2)O(2)-induced oxidative DNA lesions by overriding apoptosis.

Alanyl-glutamine enriched total parenteral nutrition improves local, systemic, and remote organ responses to intraperitoneal bacterial challenge

BACKGROUND

Standard total parenteral nutrition (STD-TPN) may diminish host defense against infection. Glutamine (Gln) is suggested to enhance host immunity. This study investigated the effects of antecedent alanyl-glutamine enriched TPN (Ala-Gln-TPN) on host responses to intraperitoneal bacterial challenge compared with STD-TPN.

METHODS

Rats were divided into STD-TPN and Ala-Gln-TPN groups. They received isocaloric and isonitrogenous nutrition for 7 days and were challenged intraperitoneally with E. coli. Rats were killed before (0 hour) challenge and at 2 and 6 hours after challenge. Bacterial numbers in peritoneal lavage fluid (PLF), liver, spleen, and blood were determined. Tumor necrosis factor-alpha (TNF), interleukin (IL)-8, and interferon-gamma (IFN) in plasma and PLF were measured. Hepatic TNF, splenic TNF, and splenic IFN levels were determined.

RESULTS

The numbers of E. coli in systemic blood at 2 hours after intraperitoneal bacterial challenge were significantly lower in the Ala-Gln-TPN than in STD-TPN group. E. coli numbers in blood significantly correlated with those in the liver. The Ala-Gln-TPN also resulted in significantly higher PLF and hepatic TNF levels, higher splenic IFN levels, and lower plasma IL-8 levels at 6 hours after challenge compared with the STD-TPN.

CONCLUSIONS

Antecedent Ala-Gln enriched TPN enhance local, systemic, and remote organ immune responses to intraperitoneal bacterial challenge. Ala-Gln-TPN may enhance host defense and be more beneficial than standard TPN in sepsis.

Magnetic quantum dot: a magnetic transmission barrier and resonator

We study the ballistic edge-channel transport in quantum wires with a magnetic quantum dot, which is formed by two different magnetic fields B(*) and B0 inside and outside the dot, respectively. We find that the electron states located near the dot and the scattering of edge channels by the dot strongly depend on whether B(*) is parallel or antiparallel to B0. For parallel fields, two-terminal conductance as a function of channel energy is quantized except for resonances, while, for antiparallel fields, it is not quantized and all channels can be completely reflected in some energy ranges. All these features are attributed to the characteristic magnetic confinements caused by nonuniform fields.

EUS in the detection of ascites and EUS-guided paracentesis

BACKGROUND

The utility of EUS was evaluated for detection of ascites and EUS-guided FNA of ascites in patients undergoing EUS for diagnosis and staging of GI malignancies.

METHODS

A series (from March 1994 to October 1997) of 571 consecutive patients who underwent upper EUS for various indications was retrospectively reviewed. Follow-up clinical information was obtained from referring physicians, subsequent CT, and telephone interviews.

RESULTS

Eighty-five patients (15% of series) were found to have ascites by EUS. Six did not have CT before EUS. Pre-EUS CT identified ascites in only 14 (18%) of the 79 patients who had pre-EUS CT. Of the patients in whom CT was negative for abdominal fluid (n = 65) and who had clinical follow-up, 13 of 58 (22%) subsequently had ascites develop that were detected by CT or physical examination. Overall, 31 of the 85 patients underwent EUS-guided FNA paracentesis; the mean volume obtained was 7.9 mL (range 1-40 mL). In 5 patients, malignant ascites was diagnosed by EUS-guided FNA; in these patients surgery was avoided.

CONCLUSIONS

EUS is more sensitive than CT in detecting small amounts of ascites. A significant number (22%) of patients who had ascites by EUS subsequently had ascites develop that was detectable by CT or physical examination. EUS-guided paracentesis appears to be safe and effective and can identify malignant ascites.

Even-odd behavior of conductance in monatomic sodium wires

With the aid of the Friedel sum rule, we perform first-principles calculations of conductances through monatomic Na wires, taking into account the sharp tip geometry and discrete atomic structure of electrodes. We find that conductances (G) depend on the number (L) of atoms in the wires; G is G(0)( = 2e(2)/h) for odd L, independent of the wire geometry, while G is generally smaller than G(0) and sensitive to the wire structure for even L. This even-odd behavior is attributed to the charge neutrality and resonant character due to the sharp tip structure. We suggest that similar even-odd behavior may appear in other monovalent atomic wires.

Tumor angiogenesis and its possible role in intravasation of colorectal epithelial cells

PURPOSE

To determine whether an increase in tumor angiogenesis facilitates intravasation of colorectal epithelial cells, we compared intratumoral microvessel counts with the presence of circulating colorectal epithelial cells in the portal venous blood from patients with colorectal carcinomas.

EXPERIMENTAL DESIGN

Circulating colorectal epithelial cells were detected by a reverse transcription-PCR assay to amplify guanylyl cyclase C (GCC) transcripts. The extent of tumor vascularization was quantitatively assessed by immunohistochemical staining with anti-CD31 antibody.

RESULTS

Colorectal epithelial cells (as measured by GCC mRNA expression) were detected in the portal venous blood in 30 of 58 patients (52%). The mean (+/- SD) microvessel count in the tumors from patients with expression of GCC mRNA in their portal venous blood was 82.74 +/- 24.97. The corresponding values in the tumors from patients without expression of GCC mRNA in portal venous blood was 65.96 +/- 19. For each 10-microvessel increase per x200 field, the risk of colorectal epithelial cell presence in the portal venous blood increased 1.52-fold (95% confidence interval, 1.19-2.12; P = 0.005).

CONCLUSION

High intratumoral vessel count was noted to be a valuable factor for predicting the presence of colorectal epithelial cells in the portal venous blood.

Mechanism for the enhanced diffusion of charged oxygen ions in SiO2

Based on real-space multigrid electronic structure calculations, we find that a double Si-O-Si bridge structure is the lowest energy configuration of interstitial oxygen ions (O(-) and O(2-)) in SiO2, where two additional Si-O bonds are formed with almost no interaction between the interstitial and host O atoms, while the peroxy linkage is the most stable structure for neutral interstitial O. We propose a diffusion mechanism of interstitial O ions generated from molecular O2 under UV radiation, and find extremely low energy barriers of 0.11--0.27 eV for migration in the form of the double-bridge structure, in good agreement with enhanced oxidation experiments.

Structural transformation in the formation of H-induced (111) platelets in Si

On the basis of first-principles calculations, we present a structural model for the formation of H-induced (111) platelets in Si, which involves a structural transformation from a double-layer-H2(*) configuration of H2(*) aggregates into an H-saturated internal (111) surface structure. This reaction process preferably occurs at high H plasma treatment temperatures and subsequently generates H2 molecules in the platelet voids, consistent with experiments. Our model also reveals the important features observed in (111) platelets, such as high-resolution transmission electron microscopy images, step structures, lattice dilation lengths, and H vibrational frequencies.

Clinicopathologic association of cyclooxygenase 1 and cyclooxygenase 2 expression in gastric adenocarcinoma

OBJECTIVE

To evaluate the association of clinicopathologic factors and prognostic value with the expression of cyclooxygenase 1 and 2 in patients with gastric adenocarcinoma.

SUMMARY BACKGROUND DATA

Epidemiologic studies have indicated that nonsteroidal antiinflammatory drugs reduce the risk of colon cancer by as much as 40% and also decrease the risk of gastric cancer. Recently, gastric cancer was found to express constitutive cyclooxygenase 1 and inducible cyclooxygenase 2 isoenzymes. Nonsteroidal antiinflammatories, which may function as cyclooxygenase inhibitors, inhibited the growth of gastric cancer cells. These two isoenzymes' expressions associated with traditional clinicopathologic factors have not been fully evaluated, and their prognostic value for determining survival in patients remains to be clarified.

METHODS

Seventy-one specimens resected from patients with gastric adenocarcinoma were investigated by immunohistochemical stain against cyclooxygenase 1 and 2. The 71 specimens were divided into stain-positive and stain-negative groups. Correlations between cyclooxygenase 1 and 2 expression, various clinicopathologic factors (including vascular invasion and Helicobacter pylori infection), and prognosis were studied.

RESULTS

The cyclooxygenase 2-positive group was significantly correlated with vascular invasion and H. pylori infection by univariate and multivariate analysis. In patients with cyclooxygenase 2-positive cancer, the prognosis was significantly poorer than in those with cyclooxygenase 2-negative cancer. However, multivariate analysis showed that vascular invasion, serosal invasion, and lymph node metastasis were independent prognostic factors for patients with gastric cancer, but cyclooxygenase 2 expression was not. There was no significant correlation between cyclooxygenase 1 expression and clinicopathologic factors and prognosis.

CONCLUSIONS

Upregulated cyclooxygenase 2 expression was associated with H. pylori infection in gastric cancer and was also strongly correlated with positive vascular invasion, which was an independent prognostic factor for poorer survival in this study. The usefulness of cyclooxygenase 2 inhibitors in the prevention or treatment of gastric cancer remains undetermined but deserves further investigation.

Breast cancer screening in Taiwan and China

In contrast to incidence rates prevailing in women in Western countries, Chinese women in Taiwan and China are considered to have the lowest incidence of breast cancer in the world. However, in the past 20 years, breast cancer incidence in Chinese women has seen a dramatic increase of 50-100%, which strongly supports the need for breast cancer prevention and screening programs. It is also important to indicate that breast cancer in Chinese women is characterized by younger age at tumor onset. More than 50% of the total breast cancer diagnosed annually is found in premenopausal patients, creating the need to initiate breast cancer screening programs in this population. Initially, the breast cancer screening program depended on breast self-examination. Since Chinese women have relatively small breasts, it was assumed that breast cancer was easier to detect by self-examination. However, this strategy has failed. The dilemma of breast cancer screening can be summarized by the fact that Chinese have a rapidly increasing incidence of premenopausal breast cancer, while the overall incidence is still low. Therefore, since premenopausal women have denser breasts than postmenopausal women, and Chinese women have smaller breasts and a higher percentage of dense breasts, increased mammography screening frequency may be not the sole solution to increase detection in this age group. In our experience in Taiwan, the addition of breast ultrasound may be helpful. Nearly all the nonpalpable cancers detected by mammography in our women are due to microcalcifications, and ultrasound is more sensitive in detecting nonpalpable cancers; Therefore, we suggest that a screening program, based on ultrasound to detect nonpalpable cancers not associated with microcalcifications, along with mammography within a long period, may provide more effective protection for Taiwanese and Chinese women against breast cancer.

Disability-adjusted life years for breast cancer patients in Taiwan

BACKGROUND AND PURPOSE

The incidence and mortality of breast cancer in Taiwan have increased rapidly in the past several decades, but the societal impact of deaths and disabilities due to breast cancer has not been assessed. This study estimated the disability-adjusted life years (DALYs) for breast cancer patients during 1994, and compared the results with similar data from other areas of the world.

METHODS

DALYs for breast cancer patients in Taiwan were calculated using the equation developed by Murray and Lopez. The incidence and mortality of breast cancer and the population structure were obtained from national statistics maintained by the Department of Health and the Ministry of the Interior. The age-specific mean survival time for breast cancer patients was estimated using the exponential distribution from incidence-mortality linkage of the incidence file at National Taiwan University Hospital and the National Mortality File maintained by the Department of Health.

RESULTS

There were 11,963 years of life lost (YLL) due to breast cancer during 1994, 2677 years lived with disability (YLD), and 14,640 DALYs. The YLL and DALYs per 1000 population (1.17 and 1.44) were in the middle of the world spectrum, while the YLD value per 1000 population (0.26) was closer to those of developed countries. The proportion of DALYs contributed by younger patients (< 45 years) was higher than in developed countries and similar to those in developing countries other than Sub-Saharan Africa. The DALYs per 1000 population of women younger than 45 years of age in Taiwan were also higher than those in India, China, other regions of Asia and Islands, Sub-Saharan Africa, and the Middle Eastern Crescent.

CONCLUSIONS

The disability portion (YLD) of the DALYs for breast cancer patients in Taiwan was higher than in other regions of the world. Moreover, patients younger than 45 years contributed a higher proportion of DALYs than in developed countries. The DALY value per 1000 population younger than 45 years of age was also higher than in developing countries. These results suggest that health professionals should focus more attention on programs for education, screening, and treatment of younger women.