Longitudinal Magnetic Resonance Imaging-Based Superficial Femoral Artery Velocity Measurements in Diabetic and Nondiabetic Patients With Peripheral Artery Disease

BACKGROUND

Longitudinal associations of noninvasive 2-dimensional phase-contrast magnetic resonance imaging (2D-PC-MRI) velocity markers of the superficial femoral artery (SFA) were analyzed along with the characteristics of peripheral artery disease (PAD). We hypothesized that the 2-year differences in MRI-based measures of SFA velocity were associated with longitudinal changes in markers of PAD.

METHODS

A total of 33 (11 diabetic, 22 nondiabetic) patients with PAD with baseline and 2-year follow-up MRI scans were included in this secondary analysis of the Effect of Lipid Modification on Peripheral Artery Disease after Endovascular Intervention Trial (ELIMIT). Electrocardiographically gated 2D-PC-MRI was performed at a proximal and a distal location of the distal SFA territory. SFA lumen, wall, and total vessel volumes and the normalized wall index (NWI) were analyzed.

RESULTS

Baseline characteristics did not differ between diabetic and nondiabetic PAD patients. Maximum proximal and distal SFA velocity measures did not differ between baseline and 2 years (41.98 interquartile range (IQR) (23.58-72.6) cm/s vs. 40.31 IQR (26.69-61.29) cm/s; P = 0.30). Pooled analysis (N = 33) showed that the 24-month change in the NWI was inversely associated with the 24-month change in the proximal maximal SFA velocity (beta = -168.36, R2 = 0.150, P value = 0.03). The 24-month change of the maximum velocity differences between the proximal and distal SFA locations was inversely associated with the 24-month changes in peak walking distance (beta = -0.003, R2 = 0.360, P value = 0.011).

CONCLUSION

The 2-year change of SFA plaque burden is inversely associated with the 2-year change of proximal peak SFA blood flow velocity. 2D-PC-MRI measured SFA velocity may be of interest in assessing PAD longitudinally.

Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

BACKGROUND

Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion and monitoring of individual and population health. The Global Burden of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify non-fatal health outcomes across an exhaustive set of disorders at the global and regional level. Neither effort quantified uncertainty in prevalence or years lived with disability (YLDs).

METHODS

Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For 1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis of prevalence, incidence, remission, duration, and excess mortality. Sources included published studies, case notification, population-based cancer registries, other disease registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory care data, household surveys, other surveys, and cohort studies. For most sequelae, we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations in descriptive epidemiological data, including missing data, inconsistency, and large methodological variation between data sources. For some disorders, we used natural history models, geospatial models, back-calculation models (models calculating incidence from population mortality rates and case fatality), or registration completeness models (models adjusting for incomplete registration with health-system access and other covariates). Disability weights for 220 unique health states were used to capture the severity of health loss. YLDs by cause at age, sex, country, and year levels were adjusted for comorbidity with simulation methods. We included uncertainty estimates at all stages of the analysis.

FINDINGS

Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from fewer than one case per 1 million people to 350,000 cases per 1 million people. Prevalence and severity of health loss were weakly correlated (correlation coefficient -0·37). In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990. The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs were much the same in 2010 as they were in 1990: low back pain, major depressive disorder, iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns of the leading causes of YLDs were more similar compared with years of life lost due to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria, and anaemia were important causes of YLDs in sub-Saharan Africa.

INTERPRETATION

Rates of YLDs per 100,000 people have remained largely constant over time but rise steadily with age. Population growth and ageing have increased YLD numbers and crude rates over the past two decades. Prevalences of the most common causes of YLDs, such as mental and behavioural disorders and musculoskeletal disorders, have not decreased. Health systems will need to address the needs of the rising numbers of individuals with a range of disorders that largely cause disability but not mortality. Quantification of the burden of non-fatal health outcomes will be crucial to understand how well health systems are responding to these challenges. Effective and affordable strategies to deal with this rising burden are an urgent priority for health systems in most parts of the world.

FUNDING

Bill & Melinda Gates Foundation.

Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

BACKGROUND

Measuring disease and injury burden in populations requires a composite metric that captures both premature mortality and the prevalence and severity of ill-health. The 1990 Global Burden of Disease study proposed disability-adjusted life years (DALYs) to measure disease burden. No comprehensive update of disease burden worldwide incorporating a systematic reassessment of disease and injury-specific epidemiology has been done since the 1990 study. We aimed to calculate disease burden worldwide and for 21 regions for 1990, 2005, and 2010 with methods to enable meaningful comparisons over time.

METHODS

We calculated DALYs as the sum of years of life lost (YLLs) and years lived with disability (YLDs). DALYs were calculated for 291 causes, 20 age groups, both sexes, and for 187 countries, and aggregated to regional and global estimates of disease burden for three points in time with strictly comparable definitions and methods. YLLs were calculated from age-sex-country-time-specific estimates of mortality by cause, with death by standardised lost life expectancy at each age. YLDs were calculated as prevalence of 1160 disabling sequelae, by age, sex, and cause, and weighted by new disability weights for each health state. Neither YLLs nor YLDs were age-weighted or discounted. Uncertainty around cause-specific DALYs was calculated incorporating uncertainty in levels of all-cause mortality, cause-specific mortality, prevalence, and disability weights.

FINDINGS

Global DALYs remained stable from 1990 (2·503 billion) to 2010 (2·490 billion). Crude DALYs per 1000 decreased by 23% (472 per 1000 to 361 per 1000). An important shift has occurred in DALY composition with the contribution of deaths and disability among children (younger than 5 years of age) declining from 41% of global DALYs in 1990 to 25% in 2010. YLLs typically account for about half of disease burden in more developed regions (high-income Asia Pacific, western Europe, high-income North America, and Australasia), rising to over 80% of DALYs in sub-Saharan Africa. In 1990, 47% of DALYs worldwide were from communicable, maternal, neonatal, and nutritional disorders, 43% from non-communicable diseases, and 10% from injuries. By 2010, this had shifted to 35%, 54%, and 11%, respectively. Ischaemic heart disease was the leading cause of DALYs worldwide in 2010 (up from fourth rank in 1990, increasing by 29%), followed by lower respiratory infections (top rank in 1990; 44% decline in DALYs), stroke (fifth in 1990; 19% increase), diarrhoeal diseases (second in 1990; 51% decrease), and HIV/AIDS (33rd in 1990; 351% increase). Major depressive disorder increased from 15th to 11th rank (37% increase) and road injury from 12th to 10th rank (34% increase). Substantial heterogeneity exists in rankings of leading causes of disease burden among regions.

INTERPRETATION

Global disease burden has continued to shift away from communicable to non-communicable diseases and from premature death to years lived with disability. In sub-Saharan Africa, however, many communicable, maternal, neonatal, and nutritional disorders remain the dominant causes of disease burden. The rising burden from mental and behavioural disorders, musculoskeletal disorders, and diabetes will impose new challenges on health systems. Regional heterogeneity highlights the importance of understanding local burden of disease and setting goals and targets for the post-2015 agenda taking such patterns into account. Because of improved definitions, methods, and data, these results for 1990 and 2010 supersede all previously published Global Burden of Disease results.

FUNDING

Bill & Melinda Gates Foundation.

A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

BACKGROUND

Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time.

METHODS

We estimated deaths and disability-adjusted life years (DALYs; sum of years lived with disability [YLD] and years of life lost [YLL]) attributable to the independent effects of 67 risk factors and clusters of risk factors for 21 regions in 1990 and 2010. We estimated exposure distributions for each year, region, sex, and age group, and relative risks per unit of exposure by systematically reviewing and synthesising published and unpublished data. We used these estimates, together with estimates of cause-specific deaths and DALYs from the Global Burden of Disease Study 2010, to calculate the burden attributable to each risk factor exposure compared with the theoretical-minimum-risk exposure. We incorporated uncertainty in disease burden, relative risks, and exposures into our estimates of attributable burden.

FINDINGS

In 2010, the three leading risk factors for global disease burden were high blood pressure (7·0% [95% uncertainty interval 6·2-7·7] of global DALYs), tobacco smoking including second-hand smoke (6·3% [5·5-7·0]), and alcohol use (5·5% [5·0-5·9]). In 1990, the leading risks were childhood underweight (7·9% [6·8-9·4]), household air pollution from solid fuels (HAP; 7·0% [5·6-8·3]), and tobacco smoking including second-hand smoke (6·1% [5·4-6·8]). Dietary risk factors and physical inactivity collectively accounted for 10·0% (95% UI 9·2-10·8) of global DALYs in 2010, with the most prominent dietary risks being diets low in fruits and those high in sodium. Several risks that primarily affect childhood communicable diseases, including unimproved water and sanitation and childhood micronutrient deficiencies, fell in rank between 1990 and 2010, with unimproved water and sanitation accounting for 0·9% (0·4-1·6) of global DALYs in 2010. However, in most of sub-Saharan Africa childhood underweight, HAP, and non-exclusive and discontinued breastfeeding were the leading risks in 2010, while HAP was the leading risk in south Asia. The leading risk factor in Eastern Europe, most of Latin America, and southern sub-Saharan Africa in 2010 was alcohol use; in most of Asia, North Africa and Middle East, and central Europe it was high blood pressure. Despite declines, tobacco smoking including second-hand smoke remained the leading risk in high-income north America and western Europe. High body-mass index has increased globally and it is the leading risk in Australasia and southern Latin America, and also ranks high in other high-income regions, North Africa and Middle East, and Oceania.

INTERPRETATION

Worldwide, the contribution of different risk factors to disease burden has changed substantially, with a shift away from risks for communicable diseases in children towards those for non-communicable diseases in adults. These changes are related to the ageing population, decreased mortality among children younger than 5 years, changes in cause-of-death composition, and changes in risk factor exposures. New evidence has led to changes in the magnitude of key risks including unimproved water and sanitation, vitamin A and zinc deficiencies, and ambient particulate matter pollution. The extent to which the epidemiological shift has occurred and what the leading risks currently are varies greatly across regions. In much of sub-Saharan Africa, the leading risks are still those associated with poverty and those that affect children.

FUNDING

Bill & Melinda Gates Foundation.

Determining pore size distribution in wet cellulose by measuring solute exclusion using a differential refractometer

Solute exclusion was used to determine the pore volume and micropore size distribution of wet cellulosic materials. Glucose, cellobiose, and polyethylene glycol (PEG) (8 to 130 A in diameter) were used as molecular probes. Four replicates of cellulosic samples, with each sample being analyzed 4 to 8 times, gave the concentrations of each molecular probe before and after contact with cellulose. Sugar concentrations were determined by the DNS method and PEG concentrations by a differential refractometer. Deviations arising from sample-to-sample variability result in variations of solute uptake from which the pore size distribution was determined. The need for replicate samples and a statistical approach to data analysis is indicated. Consequently, the data were fitted to an empirical logistic model function based on the minimum of the residual sum of squares using the finite-difference, Levenberg-Marquardt algorithm. A smooth increasing function resulted. We report experimental methodology employing a differential refractometer, common in many laboratories having a liquid chromato-graph instrument, combined with statistical treatment of the data. This method may also find application in determining pore size distribution in wet, hydrophilic polymers used in some types of membranes, chromatographic supports, and gel-type resins.

Predictors of acid suppression success in patients with chronic laryngitis

BACKGROUND

Up to 50% of the patients suspected of reflux laryngitis syndrome failed to respond to acid suppression therapy. However, predictors of acid suppression success have not been determined.

METHODS

Consecutive patients with chronic laryngitis were enrolled prospectively. All the patients underwent laryngoscopy, esophagogastroduodenoscopy and 24-h multichannel intraluminal impedance and pH (MII-pH) monitoring before receiving rabeprazole 10 mg b.i.d. for 3 months. Patient was considered as a responder to acid suppression if the chief laryngeal complaint score during the last week since last interview had decreased by at least 50% after the start of therapy compared with baseline. Cox regression analysis was used to determine the independent predictors of acid suppression success.

KEY RESULTS

Of 92 patients (age 42.4 ± 14.3 years, 50 women), 42 (45.7%) responded to acid suppression after 3 months. Gastroesophageal reflux disease was defined in 22 patients, of whom 19 patients had pathological distal esophageal acid exposure and 5 were defined as erosive esophagitis. The time to response showed a significant hazard ratio for patients with increased distal esophageal acid exposure time (β: 0.93; HR: 2.55; 95% CI: 1.24-5.24; P = 0.011) and increased laryngopharyngeal bolus exposure time (BET; β: 0.96; HR: 2.61; 95% CI: 1.36-5.00; P = 0.004). The latter had the best Youden Index (0.34) and accuracy (68.5%).

CONCLUSIONS & INFERENCES

The success of acid suppression on chronic laryngitis could be predicted using reflux parameters detected by MII-pH, among which increased laryngopharyngeal BET is the best.

Primary vs. delayed resection for obstructive left-sided colorectal cancer: impact of surgery on patient outcome

PURPOSE

By comparing surgical outcomes between primary and delayed resection, we addressed whether and how surgical strategies impacted prognosis of patients with left-sided colorectal cancer underwent emergency curative resection.

METHODS

Between January 1980 and December 2002, a total of 143 patients were identified who presented with obstructive left-sided colorectal cancer and received emergency curative resection in Taipei Veterans General Hospital. Patients were stratified according to the timing of tumor resection into two groups: primary resection and delayed resection. Demographic data of the patients, characteristics of the tumors, and short-term and long-term outcomes were analyzed and compared between the two groups.

RESULTS

The demographic data and tumor characteristics did not differ between the two groups except for more rectal cancers in the delayed resection group (P=0.021). Primary resection group had a higher anastomotic leakage rate (P=0.017) and a trend toward a higher mortality rate, which did not reach statistical significance (P=0.063). The median follow-up intervals were similar (60.4 vs. 58.3 months; P=0.79). The median survival tended to be longer in delayed resection group (66 vs. 105 months; P=0.088). Overall five-year and ten-year survival for primary resection were 43.7 and 31.9 percent, respectively, compared with 67.2 and 53.2 percent, respectively, for delayed resection.

CONCLUSIONS

Delayed resection seems to be a safer procedure and provided a better oncologic outcome compared with primary resection in obstructive left-sided colorectal cancer under emergency situations.

Increasing live donor kidney transplantation: a randomized controlled trial of a home-based educational intervention

With the shortage of deceased donor kidneys and the superior clinical outcomes possible with live donor kidney transplantation (LDKT), more patients should seriously consider LDKT. However, little is known about how best to educate patients and their family members about LDKT. We evaluated the effectiveness of a home-based (HB) educational program in increasing LDKT. Patients were randomized to clinic-based (CB) education alone (CB, n = 69) or CB plus HB education (CB+HB, n = 63). Compared to CB, more patients in the CB+HB group had living donor inquiries (63.8% vs. 82.5%, p = 0.019) and evaluations (34.8% vs. 60.3%, p = 0.005) and LDKTs (30.4% vs. 52.4%, p = 0.013). Assignment to the CB+HB group, White race, more LDKT knowledge, higher willingness to discuss LDKT with others, and fewer LDKT concerns were predictors of having LDKT (p-values < 0.05). Both groups demonstrated an increase in LDKT knowledge after the CB education, but CB+HB led to an additional increase in LDKT knowledge (p < 0.0001) and in willingness to discuss LDKT with others (p < 0.0001), and a decrease in LDKT concerns (p < 0.0001). Results indicate that an HB outreach program is more effective in increasing LDKT rates than CB education alone.

Colorectal cancer in patients 20 years old or less in Taiwan

BACKGROUND

Colorectal cancer (CRC) is predominantly a disease of the elderly population, but it sometimes occurs in young patients. The diagnosis of CRC in youngsters is often overlooked by physicians or presentation may be delayed.

METHODS

With assistance from the cancer registry center of Taipei Veterans General Hospital, we collected data on all types of colorectal malignancy, including carcinoma, adenocarcinoma, or lymphoma in patients aged 20 or younger. All available medical charts and pathologic specimens were reviewed in detail.

RESULTS

A total of 28 cases were analyzed. The leading presenting symptom was abdominal pain (92%). The locations of the primary tumors were evenly distributed, and the major histologic type was predominantly adenocarcinoma. However, the proportion of mucinous adenocarcinoma was higher than that in the older population. Most of the cases were advanced (11 tumors were classified as Dukes stage C and another 11 as Dukes stage D). The overall 5-year survival rate was 21%.

CONCLUSIONS

Despite the rarity of CRC during the first two decades of life, physicians need to be aware of the possibility and to evaluate suggestive signs and symptoms by colonoscopy or barium enema. Family history of CRC, inflammatory bowel disease, previous polyps, or familial polyposis did not play a crucial role in this group of young patients.

Gasless laparoscopy-assisted colorectal surgery

BACKGROUND

Laparoscopy has gained wide acceptance as a treatment modality in a variety of colonic and rectal disorders. Currently, most laparoscopic procedures are performed using a carbon dioxide (CO2) pneumoperitoneum, which can lead to cardiopulmonary loading and subsequent complications. The object of this study was to assess the feasibility of gasless laparoscopy-assisted colorectal surgery (GLACS) as an alternative method.

METHODS

Patients with benign colonic lesions were enrolled in the study. The operative field was exposed with a subcutaneous wire lifting system. A small incision, ~5 cm in length, was made early in the operation. The surgeon operated through the trocar ports and this incision using both laparoscopic and conventional instruments. The cardiopulmonary responses of the patients were monitored continuously during the operation.

RESULTS

Fifteen consecutive patients underwent GLACS. In two patients (13.3%), conversion to open surgery was necessary. The exposure and ease of the procedure were acceptable. However, when the patients were stratified into hemicolectomy and sigmoidectomy groups, GLACS scored more favorably in the sigmoidectomy group. There were no operative deaths. One minor complication developed postoperatively. All of the patients recovered uneventfully, with return of bowel function in 2.8 +/- 0.1 days. The mean postoperative hospital stay was 6.4 +/- 0.4 days. The cardiac and pulmonary status of the patients remained stable during the operation.

CONCLUSION

Gasless laparoscopy-assisted colorectal surgery is technically feasible; thus, it provides an alternative means for the performance of minimal-access surgery.

Preservation of anal sphincter function after hemorrhoidectomy under local anesthesia

BACKGROUND

This is a prospective study designed to confirm a simple, effective method of hemorrhoidectomy that can be accomplished by simple local anesthesia with good preservation of anal sphincter function both clinically and manometrically.

METHODS

Eighty consecutive patients with prolapsed mixed hemorrhoids were operated with standard closed hemorrhoidectomy under local anesthesia. Pre- and post-operative assessments of anal continent function and anorectal manometry were performed. Maximal basal pressure (MBP), maximal contraction pressure (MCP), squeeze pressure (SP), rectoanal inhibitory reflex (RAIR), functional length (FL), volumes at the first sensation of rectal fullness (V sense), urge of defecation (V urge), and intolerance (V max.) were measured. The pre-and post-operative data were compared with two tailed paired Student t test. Statistical significance was considered asp-value less than 0.05.

RESULTS

All 80 patients were completely followed up and studied. No patient had any degree of anal incontinence before and 6 months after hemorrhoidectomy. There was significant change in V sense and V urge after operation. However, MBP, MCP, SP, FL, RAIR, and V max. remained unchanged.

CONCLUSIONS

Standard closed hemorrhoidectomy supplemented with appropriate submucosal dissection under adequate local anesthesia is simple and effective for the treatment of prolapsed hemorrhoids. The function of anal sphincter, both clinically and manometrically, can be well preserved.

Suppression of Fas ligand expression on endothelial cells by arsenite through reactive oxygen species

Chronic exposure to arsenite is associated with vascular disease, such as arteriosclerosis. However, the cellular mechanisms for vascular disease in response to arsenic are not well known. The present study has demonstrated that arsenite not arsenate decreased the Fas ligand (FasL) expression on ECV304 cells through reactive oxygen species. Incubation of ECV304 cells with arsenite decreased the FasL expression and increased the intracellular peroxide levels. In addition, hydrogen peroxide was found to suppress FasL expression in a dose-dependent manner. The antioxidant, N-acetyl-cysteine, blocked the suppression of FasL expression in response to arsenite. These data suggested that arsenite initiates endothelium dysfunction, at least partly, by suppressing the FasL expression through activating reactive oxygen species sensitive endothelial cell signaling.

Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions

Curcumin (diferuloylmethane), a yellow substance from the root of the plant Curcuma longa Linn., has been demonstrated to inhibit carcinogenesis of murine skin, stomach, intestine and liver. However, the toxicology, pharmacokinetics and biologically effective dose of curcumin in humans have not been reported. This prospective phase-I study evaluated these issues of curcumin in patients with one of the following five high-risk conditions: 1) recently resected urinary bladder cancer; 2) arsenic Bowen's disease of the skin; 3) uterine cervical intraepithelial neoplasm (CIN); 4) oral leucoplakia; and 5) intestinal metaplasia of the stomach. Curcumin was taken orally for 3 months. Biopsy of the lesion sites was done immediately before and 3 months after starting curcumin treament. The starting dose was 500 mg/day. If no toxicity > or = grade II was noted in at least 3 successive patients, the dose was then escalated to another level in the order of 1,000, 2,000, 4,000, 8,000, and 12,000 mg/day. The concentration of curcumin in serum and urine was determined by high pressure liquid chromatography (HPLC). A total of 25 patients were enrolled in this study. There was no treatment-related toxicity up to 8,000 mg/day. Beyond 8,000 mg/day, the bulky volume of the drug was unacceptable to the patients. The serum concentration of curcumin usually peaked at 1 to 2 hours after oral intake of crucumin and gradually declined within 12 hours. The average peak serum concentrations after taking 4,000 mg, 6,000 mg and 8,000 mg of curcumin were 0.51 +/- 0.11 microM, 0.63 +/- 0.06 microM and 1.77 +/- 1.87 microM, respectively. Urinary excretion of curcumin was undetectable. One of 4 patients with CIN and 1 of 7 patients with oral leucoplakia proceeded to develop frank malignancies in spite of curcumin treatment. In contrast, histologic improvement of precancerous lesions was seen in 1 out of 2 patients with recently resected bladder cancer, 2 out of 7 patients of oral leucoplakia, 1 out of 6 patients of intestinal metaplasia of the stomach, I out of 4 patients with CIN and 2 out of 6 patients with Bowen's disease. In conclusion, this study demonstrated that curcumin is not toxic to humans up to 8,000 mg/day when taken by mouth for 3 months. Our results also suggest a biologic effect of curcumin in the chemoprevention of cancer.

Suppression of inducible cyclooxygenase and nitric oxide synthase through activation of peroxisome proliferator-activated receptor-gamma by flavonoids in mouse macrophages

Peroxisome proliferator-activated receptor (PPAR)gamma transcription factor has been implicated in anti-inflammatory response. Of the compounds tested, apigenin, chrysin, and kaempferol significantly stimulated PPAR gamma transcriptional activity in a transient reporter assay. In addition, these three flavonoids strongly enhanced the inhibition of inducible cyclooxygenase and inducible nitric oxide synthase promoter activities in lipopolysaccharide-activated macrophages which contain the PPAR gamma expression plasmids. However, these three flavonoids exhibited weak PPAR gamma agonist activities in an in vitro competitive binding assay. Limited protease digestion of PPAR gamma suggested these three flavonoids produced a conformational change in PPAR gamma and the conformation differs in the receptor bound to BRL49653 versus these three flavonoids. These results suggested that these three flavonoids might act as allosteric effectors and were able to bind to PPAR gamma and activate it, but its binding site might be different from the natural ligand BRL49653.

Mechanisms of cancer chemoprevention by curcumin

Curcumin is a major component of the Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animals as indicated by its ability to block colon tumor initiation by azoxymethane and skin tumor promotion induced by phorbol ester TPA. Recently, curcumin has been considered by oncologists as a potential third generation cancer chemopreventive agent, and clinical trials using it have been carried out in several laboratories. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes, such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase. Curcumin is also a potent inhibitor of protein kinase C, EGF-receptor tyrosine kinase and IkappaB kinase. In addition, curcumin inhibits the activation of NFkappaB and the expression of c-jun, c-fos, c-myc and iNOS. It is proposed that curcumin may suppress tumor promotion by blocking signal transduction pathways in the target cells. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin, and these compounds were subsequently convened into monoglucuronide conjugates. The experimental results suggest that curcumin-glucuronide, dihydrocurcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are major metabolites of curcumin in mice.

Carcinoembryonic antigen in monitoring of response to systemic chemotherapy in patients with metastatic colorectal cancer

The response to chemotherapy of solid tumors is generally assessed by measuring tumors visualized by imaging. However, the response assessment based on imaging is not always feasible because patients often have disease not measurable by imaging, such as diffuse peritoneal dissemination. We evaluated the correlation between the change on imaging and change in CEA levels for assessing chemotherapeutic response of patients with metastatic colorectal cancer. Between July 1993 and August 1999 we retrospectively examined 136 patients with metastatic colorectal carcinoma, all of whom had measurable lesions. Forty patients received oral tegafur-uracil (300 mg/m2/day) plus folinic acid (60 mg/day) for 4 weeks, repeated every 5 weeks, as the firstline treatment. Another 96 patients received either a weekly intravenous bolus injection of 5-fluorouracil (400 mg/m2) plus folinic acid (20 mg/m2), or an intravenous bolus injection of 5-fluorouracil (425 mg/m2) plus folinic acid (20 mg/m2) for 5 consecutive days every month. Responders, based on CEA assessment, were defined as those with a greater than 50% drop in CEA level for more than 4 weeks. The pretreatment CEA levels were elevated beyond the normal cutoff value in 110 (81%) patients. A response rate of 18.4% (95% CI, 11.9-24.9%), including 8 complete remissions and 17 partial remissions, was achieved according to imaging studies. The response rate assessed by CEA was 25% (34/136). Sixteen responders (47%) based on CEA had no remission on imaging. The sensitivity of change in CEA levels in the prediction of true responders and progressive diseases on imaging were 72% and 81%, respectively. In terms of the positive predictive value, change in CEA levels in the prediction of true responders and progressive disease on imaging were 53% and 85%, respectively. Patients with remarkable falls on CEA levels survived significantly longer than nonresponders (P < 0.001, log-rank test). At follow-up of 48 months the median survival for responders and nonresponders assessed by CEA was 28 months and 13 months, respectively. These data suggest that measurement of CEA levels might be helpful in monitoring chemotherapeutic response when imaging study is unsuitable for assessing the response in clinical practice. Furthermore, measurement of CEA levels may be helpful in determining the prognosis of patients with metastatic colorectal cancer receiving chemotherapy.

Griseofulvin potentiates antitumorigenesis effects of nocodazole through induction of apoptosis and G2/M cell cycle arrest in human colorectal cancer cells

In this study, we demonstrate that apoptosis and G2/M cell cycle arrest were easily induced by treatment with the oral-antifungal agent, griseofulvin (GF). The mechanisms of GF-induced G2/M arrest were characterized as (a) induction of abnormal mitotic spindle formation, (b) elevation of cyclin B1/cdc2 kinase activity and (c) down-regulation of myt-1 protein expression. On the other hand, caspase 3 activation, Bcl-2 hyperphosphorylation and inhibition of the normal function of Bcl-2 associated with Bax were demonstrated to be the mechanisms of GF-induced apoptosis. DNA fragmentation and flow cytometry analyses demonstrated that combined treatment of GF with the cancer chemotherapeutic agent, nocodazole (ND), strongly potentiates the apoptotic effect and arrest of the G2/M cell cycle in 5 types of human cancer cells, but not in normal human keratinocytes (#76 KhGH). The combined treatment of GF and ND triggered the polymerization of purified tubulin in HT 29 but not in #76 KhGH cells. To further confirm these observations, the therapeutic efficacy was further examined in vivo by treating athymic mice bearing COLO 205 tumor xenografts, with GF (50 mg/kg), ND (5 mg/kg) or GF + ND. Combined treatment of GF and ND significantly enhanced the effect of ND, and led to cessation of tumor growth. These results suggest that chemotherapeutic agents (such as ND) administered in the presence of GF might provide a novel therapy for colorectal cancer.

Oxidative stress and c-Jun-amino-terminal kinase activation involved in apoptosis of primary astrocytes induced by disulfiram-Cu(2+) complex

Disulfiram is frequently used in the treatment of alcoholism. In this study, we found that CuCl(2) (1-10 microM), but not other metal ions (Fe(2+), Zn(2+), Pb(2+)), markedly potentiated disulfiram-induced cytotoxicity by 440-fold in primary astrocytes. Thus, the molecular mechanisms of the cytotoxic effects induced by the disulfiram-Cu(2+) complex were explored. The changes in morphology (nuclear condensation and apoptotic body formation) and hypodiploidy of DNA suggested that the disulfiram-Cu(2+) complex induced an apoptotic process. Our studies of the death-signaling pathway reveal that decreased mitochondrial membrane potential, increased free radical production, and depletion of non-protein-thiols (glutathione) were involved. The disulfiram-Cu(2+) complex activated c-Jun-amino-terminal kinase (JNK) and caspase-3 followed by poly (ADP-ribose) polymerase degradation in a time-dependent manner. Moreover, the cellular Cu content was markedly increased and the copper chelator bathocuproine disulfonate abolished all of these cellular events, suggesting that Cu(2+) is essential for death signaling. The antioxidants N-acetylcysteine and vitamin C also inhibited the cytotoxic effect. Thus, we conclude that the disulfiram-Cu(2+) complex induces apoptosis and perhaps necrosis at a late stage mediated by oxidative stress followed by sequential activation of JNK, caspase-3 and poly (ADP-ribose) polymerase degradation. These findings imply that the axonal degeneration and neurotoxicity observed after the chronic administration of disulfiram are perhaps, at least in part, due to the cytotoxic effect of the disulfiram-Cu(2+) complex formed endogenously.

Alternative activation of extracellular signal-regulated protein kinases in curcumin and arsenite-induced HSP70 gene expression in human colorectal carcinoma cells

We have investigated the regulation mechanism of chemical stress-induced HSP70 gene expression in human colorectal carcinoma cells (COLO205 and HT29). Our data show that chemical treatments including sodium arsenite and curcumin, induced significant synthesis of HSP70 and its mRNA. The induced HSP70 gene expression appears to be increased at the transcriptional level. The increase in HSP70 gene expression by both chemicals is associated with an increase in HSF binding to HSE and induction of HSF1 di- or trimerization. Phosphorylation and activation of extracellular signal-regulated proteins (ERK1/2) were detected in sodium arsenite-treated COLO205 and HT29 cells, and the free radical scavenger N-acetyl-L-cysteine (NAC) was able to inhibit this ERK1/2 activation and HSP70 gene expression. MAPK blockade by the specific MEK1 inhibitor (PD98059) decreased the ability of sodium arsenite to increase HSP70 gene expression in a dose-dependent manner along with dephosphorylation of ERK1/2 proteins. In contrast to arsenite treatment, activation of ERK1/2 was not detected in curcumin-treated colorectal carcinoma cells, and NAC and PD98059 did not show any inhibitory effect on HSP70 gene expression induced by curcumin. Overexpression of a dominant negative mutant of mitogen-activated protein kinase kinase kinase 1 (MEKK1-DN) prevents arsenite-induced ERK1/2 phosphorylation and HSP70 protein synthesis. These results indicated that the ERK signaling pathway can participate in HSP70 gene expression induced by the prooxidant sodium arsenite, but not by the antioxidant curcumin.

Induction of apoptosis by garcinol and curcumin through cytochrome c release and activation of caspases in human leukemia HL-60 cells

Garcinol, a polyisoprenylated benzophenone, was purified from Garcinia indica fruit rind. The effects of garcinol and curcumin on cell viability in human leukemia HL-60 cells were investigated. Garcinol and curcumin displayed strong growth inhibitory effects against human leukemia HL-60 cells, with estimated IC(50) values of 9.42 and 19.5 microM, respectively. Garcinol was able to induce apoptosis in a concentration- and time-dependent manner; however, curcumin was less effective. Treatment with garcinol caused induction of caspase-3/CPP32 activity in a dose- and time-dependent manner, but not caspase-1 activity, and induced the degradation of poly(ADP-ribose) polymerase (PARP). Pretreatment with caspase-3 inhibitor inhibited garcinol-induced DNA fragmentation. Treatment with garcinol (20 microM) caused a rapid loss of mitochondrial transmembrane potential, release of mitochondrial cytochrome c into cytosol, and subsequent induction of procaspase-9 processing. The cleavage of D4-GDI, an abundant hematopoietic cell GDP dissociation inhibitor for the Ras-related Rho family GTPases, occurred simultaneously with the activation of caspase-3 but preceded DNA fragmentation and the morphological changes associated with apoptotic cell death. Of these, Bcl-2, Bad, and Bax were studied. The level of expression of Bcl-2 slightly decreased, while the levels of Bad and Bax were dramatically increased in cells treated with garcinol. These results indicate that garcinol allows caspase-activated deoxyribonuclease to enter the nucleus and degrade chromosomal DNA and induces DFF-45 (DNA fragmentation factor) degradation. It is suggested that garcinol-induced apoptosis is triggered by the release of cytochrome c into the cytosol, procaspase-9 processing, activation of caspase-3 and caspase-2, degradation of PARP, and DNA fragmentation caused by the caspase-activated deoxyribonuclease through the digestion of DFF-45. The induction of apoptosis by garcinol may provide a pivotal mechanism for its cancer chemopreventive action.

Griseofulvin potentiates antitumorigenesis effects of nocodazole through induction of apoptosis and G2/M cell cycle arrest in human colorectal cancer cells

In this study, we demonstrate that apoptosis and G2/M cell cycle arrest were easily induced by treatment with the oral-antifungal agent, griseofulvin (GF). The mechanisms of GF-induced G2/M arrest were characterized as (a) induction of abnormal mitotic spindle formation, (b) elevation of cyclin B1/cdc2 kinase activity and (c) down-regulation of myt-1 protein expression. On the other hand, caspase 3 activation, Bcl-2 hyperphosphorylation and inhibition of the normal function of Bcl-2 associated with Bax were demonstrated to be the mechanisms of GF-induced apoptosis. DNA fragmentation and flow cytometry analyses demonstrated that combined treatment of GF with the cancer chemotherapeutic agent, nocodazole (ND), strongly potentiates the apoptotic effect and arrest of the G2/M cell cycle in 5 types of human cancer cells, but not in normal human keratinocytes (#76 KhGH). The combined treatment of GF and ND triggered the polymerization of purified tubulin in HT 29 but not in #76 KhGH cells. To further confirm these observations, the therapeutic efficacy was further examined in vivo by treating athymic mice bearing COLO 205 tumor xenografts, with GF (50 mg/kg), ND (5 mg/kg) or GF + ND. Combined treatment of GF and ND significantly enhanced the effect of ND, and led to cessation of tumor growth. These results suggest that chemotherapeutic agents (such as ND) administered in the presence of GF might provide a novel therapy for colorectal cancer.

Induction of apoptosis by the oolong tea polyphenol theasinensin A through cytochrome c release and activation of caspase-9 and caspase-3 in human U937 cells

This study examined the growth inhibitory effects of theasinensin A (from oolong tea) and black tea polyphenols, including theaflavin (TF-1), a mixture (TF-2) of theaflavin-3-gallate (TF-2a) and theaflavin-3'-gallate (TF-2b), and theaflavin-3,3'-digallate (TF-3) in human cancer cells. Theasinensin A, TF-1, and TF-2 displayed strong growth inhibitory effects against human histolytic lymphoma U937, with estimated IC50 values of 12 microM, but were less effective against human acute T cell leukemia Jurkat, whereas TF-3 and (-)-epigallocatechin-3-gallate (EGCG) had lower activities. The molecular mechanisms of tea polyphenol-induced apoptosis as determined by annexin V apoptosis assay, DNA fragmentation, and caspase activation were further investigated. Loss of membrane potential and reactive oxygen species (ROS) generation were also detected by flow cytometry. Treatment with tea polyphenols caused rapid induction of caspase-3, but not caspase-1, activity and stimulated proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Pretreatment with a potent caspase-3 inhibitor, Z-Asp-Glu-Val-Asp-fluoromethyl ketone, inhibited theasinensin A induced DNA fragmentation. Furthermore, it was found that theasinensin A induced loss of mitochondrial transmembrane potential, elevation of ROS production, release of mitochondrial cytochrome c into the cytosol, and subsequent induction of caspase-9 activity. These results indicate that theasinensin A allows caspase-activated deoxyribonuclease to enter the nucleus and degrade chromosomal DNA and induces DFF-45 (DNA fragmentation factor) degradation. The results suggest that induction of apoptosis by theasinensin A may provide a pivotal mechanism for their cancer chemopreventive function.

Ketoconazole induces G0/G1 arrest in human colorectal and hepatocellular carcinoma cell lines

Ketoconazole is an oral-antifungal agent that has been used worldwide in the treatment of some hormone-dependent human cancer. In this study, we demonstrated that ketoconazole (20 microM) induced various types of human cancer cell growth arrest in the G0/G1 phase. Our results revealed that ketoconazole-induced growth arrest was more profound in COLO 205 and Hep G2 (with wild-type p53) than in HT 29 (p53 His(273) mutant) and Hep 3B (with deleted p53) cells. The protein levels of p53, p21/Cip1, and p27/Kip1 were significantly elevated by ketoconazole (10 microM) treatment in COLO 205 but not in HT 29 cells. The ketoconazole-induced G0/G1 phase arrest in COLO 205 cells was attenuated by p53-specific antisense oligodeoxynucleotides (20 microM) treatment. These results suggested that the p53-associated signaling pathway is involved in the regulation of ketoconazole-induced cancer cell growth arrest. By Western blot analysis, we demonstrated that cyclin D3 and CDK4 protein but not other G0/G1 phase regulatory protein levels were decreased by ketoconazole-treatment in both COLO 205 and HT 29 cells. Our study provides the basis of molecular mechanisms for ketoconazole in growth inhibition of human cancer cells and such results may have significant applications for cancer chemotherapy.

Comparative studies on the suppression of nitric oxide synthase by curcumin and its hydrogenated metabolites through down-regulation of IkappaB kinase and NFkappaB activation in macrophages

Nitric oxide (NO) plays an important role in inflammation and in the multiple stages of carcinogenesis. In this study, we investigated the inhibitory effects of curcumin and its metabolites, tetrahydrocurcumin, hexahydrocurcumin, and octahydrocurcumin, on the induction of NO synthase (NOS) in RAW 264.7 cells activated with lipopolysaccharide (LPS). Western blotting and northern blotting analyses demonstrated that curcumin strongly reduced 130-kDa protein and 4.5-kb mRNA levels of iNOS in LPS-activated macrophages compared with its metabolites, tetrahydrocurcumin, hexahydrocurcumin, and octahydrocurcumin. Moreover, electrophoretic mobility shift assay (EMSA) experiments indicated that curcumin blocked the LPS-induced binding of nuclear factor-kappaB (NFkappaB), a transcription factor necessary for iNOS induction to its (32)P-labeled double-stranded oligonucleotide probe. The inhibition of NFkappaB activation occurred through the prevention of inhibitor kappaB (IkappaB) degradation. Transient transfection experiments also showed that curcumin inhibited NFkappaB-dependent transcriptional activity. Curcumin blocked the disappearance of inhibitory kappaBalpha (IkappaBalpha) and p65 from the cytosolic fraction, and inhibited the phosphorylation of IkappaBalpha. Furthermore, we showed that curcumin could inhibit the IkappaB kinase 1 (IKK1) and IkappaB kinase 2 (IKK2) activities induced by LPS, but tetrahydrocurcumin, hexahydrocurcumin, and octahydrocurcumin were less active. These results suggest that curcumin may exert its anti-inflammatory and anti-carcinogenic properties by suppressing the activation of NFkappaB through inhibition of IKK activity.

Randomized trial comparing weekly bolus 5-fluorouracil plus leucovorin versus monthly 5-day 5-fluorouracil plus leucovorin in metastatic colorectal cancer

BACKGROUND/AIMS

The purpose of this study was to compare the efficacy and toxicity profiles of weekly intravenous (i.v.) bolus injection of 5-fluorouracil plus low-dose leucovorin with the Mayo Clinics' monthly 5-day schedule of 5-fluorouracil and leucovorin in the treatment of metastatic colorectal cancer.

METHODOLOGY

A total of 96 patients with previously untreated metastatic colorectal cancer were randomized to receive either a weekly i.v. bolus injection of 5-fluorouracil 400 mg/m2 plus leucovorin 20 mg/m2 (weekly arm), or i.v. bolus injection of 5-fluorouracil 425 mg/m2 plus leucovorin 20 mg/m2 for 5 consecutive days every 4 or 5 weeks (monthly arm). Therapy was continued until disease progression or unacceptable toxicity appeared. In the presence of disease progression, the study regimen was stopped and second-line treatment was instituted after the patient was discontinued from this study.

RESULTS

There was no significant difference of response rates between both regimens. The response rate were 14.3% in the weekly arm (2 CR and 5 PR, 95% CI: 2.6-25.2%) and 10.6% in the monthly arm (1 CR and 4 PR; 95% CI: 6.5-32.3%), respectively (P = 0.8957). The survival times were also similar between the two (P = 0.4207, log-rank test). The median survival were 15.8 months in the monthly arm and 18.4 months in the weekly arm. Hematologic toxicity was minimal in both arms. However, the monthly arm produced a higher toxicity in severe (grade 3-4) diarrhea (14.9% vs. 2%; P = 0.029) and stomatitis (8.5% vs. 0; P = 0.054).

CONCLUSIONS

Weekly bolus injection of 5-fluorouracil and low-dose leucovorin achieved a similar response rate and survival as compared with the Mayo Clinics' monthly 5-day schedule, but severe toxicity was less commonly seen using the weekly regimen. As current chemotherapeutic treatment for metastatic colorectal cancer is largely palliative rather than curative, the weekly bolus regimen may be a more favorable approach in managing metastatic colorectal cancer.

Phase II study of oral tegafur-uracil and folinic acid as first-line therapy for metastatic colorectal cancer: Taiwan experience

BACKGROUND

Tegafur-uracil has become an important regimen in the treatment of metastatic colorectal cancer. Tegafur is a prodrug that is converted to 5-fluorouracil (5-FU) and has been reported to be less toxic and to have a higher therapeutic index. The additional advantage of tegafur is oral administration, an important consideration to improve the quality of life in these patients. Tegafur in combination with uracil is thought to have greater anti-tumor activity due to the inhibitory effect of uracil on the degradation of 5-FU by hepatic dihydropyrimidine dehydrogenase. Tegafur with folinic acid has been reported with modest efficacy and acceptable toxicity. The purpose of this study was to evaluate the effectiveness and toxicity profile of oral tegafur-uracil plus folinic acid in Chinese patients with metastatic colorectal cancer.

METHODS

Between May 1998 and August 1999, 40 patients with metastatic colorectal carcinoma were enrolled in this study. All the patients had to have measurable lesions. The initial dose of tegafur-uracil was 300 mg/m2/day for 28 days, followed by a 7-day rest period. Folinic acid was administered orally at a dose of 60 mg/day concurrently with tegafur-uracil. For patients with neutrophil count <1500/microl or a platelet count <100,000/microl after treatment, the treatment was postponed for a maximum of 2 weeks. After that time, if the neutrophil count was 1000-1500/microl and the platelet count was 70,000-100,000 microl, the dose of tegafur-uracil was reduced by 50%, and if lower values resulted, the treatment was discontinued.

RESULTS

Forty patients received a total of 318 courses of treatment and a response rate of 32.5% (95% CI, 18-47%), including five complete remissions and eight partial remissions, was achieved. Toxicity was mild and generally tolerable. Gastrointestinal toxicities, including diarrhea, nausea and vomiting, were the major side effects. Seven incidences (17.5%) of grade 3-4 gastrointestinal toxicity were observed. Hematological toxicities were minimal with no evidence of severe (grade 3 or 4) leukopenia and thrombocytopenia. No episode of hepatic, renal, cardiac or neurological toxicity occurred. Two patients (5%) developed transient painful fissuring erythroderma over their palms and soles (the hand-foot syndrome).

CONCLUSIONS

The data from our study indicate that oral tegafur-uracil plus folinic acid is an active and tolerable first-line treatment for Chinese patients with metastatic colorectal cancer, with the additional advantage of being easily administered at home.

Factors predictive of survival in patients with node-positive colorectal cancer in Taiwan

BACKGROUND/AIMS

Preoperative CEA levels, depth of tumor penetration, and the number of positive lymph nodes were reported as independent factors prognostic of survival in colorectal cancer patients. This study was carried out in an effort to evaluate the prognostic significance of these three factors in patients with Dukes' C colorectal cancer in Taiwan.

METHODOLOGY

Between 1992 and 1994, a total of 112 patients with node-positive colorectal cancer were evaluated retrospectively at the Veteran General Hospital-Taipei. All patients underwent potentially curative surgery and received 5-fluorouracil based adjuvant chemotherapy. Reference to the Dukes' classification was according to the classical criteria described in 1932 for carcinoma of the rectum and adapted for use in colonic tumors. Data on the location of the tumor, depth of penetration, number of positive lymph nodes, degree of tumor differentiation, and preoperative CEA levels were analyzed to understand their association with survival. Blood samples for CEA measurement were taken a few days before operation. A multivariate analysis using the Cox's proportional hazards regression model was then performed to determine the most important independent predictors of survival among all the possible variables.

RESULTS

Using univariate analysis the number of positive lymph nodes (P < 0.001), penetration of the bowel wall (P < 0.001), and preoperative CEA levels (P < 0.001) were found as significant prognostic factors, while the degree of tumor differentiation, location of the tumor, age and sex were not significant. Using multivariate Cox analysis the number of positive lymph nodes, penetration of the bowel wall, and preoperative CEA levels were still found as independent prognostic factors in node-positive colorectal cancer patients.

CONCLUSIONS

Data obtained from our study indicates that preoperative CEA levels, depth of tumor penetration, and the number of positive lymph nodes were independent prognostic factors in Dukes' C colorectal cancer patients. They could serve as appropriate modifications of the initial Dukes scheme in node-positive diseases.

Inhibition by curcumin of diethylnitrosamine-induced hepatic hyperplasia, inflammation, cellular gene products and cell-cycle-related proteins in rats

Curcumin (CCM), a major yellow pigment of turmeric obtained from powdered rhizomes of the plant Curcuma longa Linn, is commonly used as coloring agent in foods, drugs and cosmetics. In this study we report that gavage administration of 200 mg/kg or 600 mg/kg CCM effectively suppressed diethylnitrosamine (DEN)-induced liver inflammation and hyperplasia in rats, as evidenced by histopathological examination. Immunoblotting analysis showed that CCM strongly inhibited DEN-mediated the increased expression of oncogenic p21(ras) and p53 proteins in liver tissues of rats. In cell-cycle-related proteins, CCM selectively reduced the expression of proliferating cell nuclear antigen (PCNA), cyclin E and p34(cdc2), but not Cdk2 or cyclin D1. Moreover, CCM also inhibited the DEN-induced increase of transcriptional factor NF-kappa B. However, CCM failed to affect DEN-induced c-Jun and c-Fos expression. It has become widely recognized that the development of human hepatocellular carcinoma (HCC) is predominantly due to the chronic inflammation by virus, bacteria or chemical. Our results suggest a potential role for CCM in the prevention of HCC.

Suppression of invasion and MMP-9 expression in NIH 3T3 and v-H-Ras 3T3 fibroblasts by lovastatin through inhibition of ras isoprenylation

Lovastatin, a hydroxymethylglutaryl coenzyme A reductase inhibitor, was found to block the synthesis of cholesterol and to affect posttranslational modification or isoprenylation, which is essential for membrane localization and biological activity of several proteins including Ras in the signal transduction pathway. Ras activates a multitude of downstream activities with roles in cellular processing, including invasion and metastasis. We investigated the anti-invasive activity of lovastatin in NIH 3T3 and v-H-Ras-transformed NIH 3T3 (v-H-Ras 3T3) cells. Lovastatin suppressed cell invasion in vitro in a dose-dependent manner. By zymographic assay, a decrease in matrix metalloproteinase-9 (MMP-9) activity but not matrix metalloproteinase-2 (MMP-2) activity by lovastatin was detected. RT-PCR demonstrated a reduction in gene expression of MMP-9 after treatment with lovastastin. To confirm the lovastatin-induced down-regulation of MMP-9 expression, we transfected an MMP-9/luciferase reporter vector, under MMP-9 promoter control, into both NIH 3T3 and v-H-Ras 3T3. A reduction in luciferase activity was observed with lovastatin treatment. In addition, lovastatin also reduced AP-1 and NFkappaB binding activities. These anti-invasive features were attenuated by the presence of mevalonate. These results suggest that down-regulation of MMP-9 contributes to the anti-invasive activity of lovastatin. Furthermore, we added exogenous mevalonate, which enhances the potency of cell invasion, and Ras farnesyltransferase inhibitor (manumycin A), which inhibits the potency of cell invasion. In accordance, Western blot analysis showed that lovastatin decreased membrane localization of Ras proteins. These data indicate that the anti-invasion activity of lovastatin happens through a decrease in Ras isoprenylation and functions.

Death signaling pathway induced by pyrrolidine dithiocarbamate-Cu(2+) complex in the cultured rat cortical astrocytes

The chelating and antioxidant effects of pyrrolidine dithiocarbamate (PDTC) have been investigated extensively for preventing cell death induced by different insults. However, the toxic effects of PDTC have been studied only recently and fewer studies on the toxic effects on astrocytes have been reported. In our study, we demonstrated that both PDTC and Cu(2+) alone were rated as only weakly toxic in inducing cell death in cortical astrocytes with IC(50) of 300 microM and 180 microM, respectively. However, PDTC and Cu(2+) in the complex form markedly potentiated with each other by about 1,000-fold with IC(50) of 0.3 microM PDTC plus 10 microM Cu(2+). Other metals at concentrations of 3-10 microM (VO(4)(5+), Cr(6+), Mn(2+), Fe(2+), Co(2+), Ni(2+), Zn(2+), Pb(2+), Bi(2+), Ba(2+), UO(2+), Cs(+), SeO(4)(2-), La(3+)) had no such potentiating effects on PDTC. Changes in morphology (nuclear condensation), apoptotic body formation, and hypodiploidity of DNA suggested that the PDTC-Cu(2+) complex induced cell death through an apoptotic process. Further studies showed that the PDTC-Cu(2+) complex decreased mitochondrial membrane potential, increased hydrogen peroxide production, and depleted GSH contents. After the increased oxidative stress, PDTC-Cu(2+) complex differentially activated JNKs, ERK, p38 and caspase 3, which caused PARP degradation in a time-dependent manner. All these effects were consistent with the increased cellular Cu contents. The nonpermeable copper-specific chelator bathocuproine disulfonate (BCPS), but not the permeable Cu(2+) chelator neocuproine, abolished all the observed effects. Antioxidants (N-acetylcysteine [NAC], vitamin C), catalase, and Cu(2+)-binding proteins (albumin, hemoglobin, and higher serum) reduced the cytotoxic effects of PDTC-Cu(2+) complex. We concluded that the death signaling pathway of PDTC-Cu(2+) complex was mediated by oxidative stress and subsequent JNK activation. These findings imply that PDTC, a widely used pesticide and medicine that is capable of penetrating the blood-brain barrier, may cause neurotoxicity through astrocyte dysfunction.

Activation of transcription factors of nuclear factor kappa B, activator protein-1 and octamer factors in hyperalgesia

Involvement of c-fos and neuronal nitric oxide synthase (nNOS) in the hyperalgesia induced by complete Freund adjuvant (CFA) has been reported. In this paper, we attempted to investigate whether the transcription factors regulating the gene expression of c-fos and nNOS, including activator protein-1 (AP-1), nuclear factor kappa B (NF-kappa B), and octamer factors (Oct), are activated by CFA during the development of hyperalgesia. The electrophoretic mobility shift assay (EMSA) was used to determine whether there were changes in the transcription factors in the lumbar spinal cord of adult rats following subcutaneous injection of CFA in one hindpaw of the rats. Maximum binding of AP-1, NF-kappa B and Oct was found at 0.5, 1 and 2 h after CFA injection, respectively. These findings suggest that the activation of these transcription factors is pivotal for the expression of c-Fos and nNOS proteins, which reached a peak at 3 and 48 h after CFA injection, respectively. The behavioral testing of hyperalgesia demonstrated that CFA reduced the thresholds for mechanical and thermal algesia, reaching a minimum at 6 h. The thresholds had only partially recovered after 96 h. Based on these findings, we conclude that AP-1, NF-kappa B and Oct are crucial for the expression of c-Fos proteins at an early stage (at 3 h) and for the expression of nNOS at a late stage of hyperalgesia (48 h post-injection) induced by CFA.

Hypotriglyceridemic effect of Anka (a fermented rice product of monascus sp.) in rats

Experimental rats with hypertriglyceridemia were prepared by feeding a high-fructose diet. Dried Anka powder (2%), a rice product fermented with Monascus sp., was mixed with basic high-fructose (30%) or basal-diet feed. Serum and liver lipids were measured after 6 months. The concentrations of serum triglycerides, total cholesterol, VLDL-C, and LDL-C had significantly decreased, whereas that of HDL-C had slightly increased in 30% fructose-Anka-fed rats as compared with the 30% fructose-fed rats, but hepatic lipase activity had increased in the Anka-fed groups. The ratio of lipoprotein lipase/hepatic lipase was not significantly different between 30% fructose-Anka-fed rats and 30% fructose-fed rats. The dietary intake and weight of these two groups were approximately the same. Similar results were obtained in noninduced hypertriglyceridemic rats. The concentrations of triglycerides and cholesterol did not significantly differ in the liver. Interestingly, Anka can suppress serum triglycerides in rats with induced hypertriglyceridemia. The antioxidant enzyme SOD activity was also measured in serum, and no significant change was observed. On the basis of these findings, we suggest that Anka may be used to suppress hypertriglyceridemia and hyperlipidemia in rats and possibly in man.

Nitration and hydroxylation of aromatic amino acid and guanine by the air pollutant peroxyacetyl nitrate

Peroxyacetyl nitrate (PAN) is a common gaseous photochemical compound in polluted air and cigarette smog. The toxicity of PAN has been found to depend on three pathways: (1) its oxidizing property that mimics peroxide or peroxynitrite; (2) its nitrating and hydroxylating properties similar to peroxynitrite; and (3) its acetylating property like acetic anhydride. The present investigations were intended to focus on the reactions of PAN with aromatic amino acids and guanine. When PAN interacted with tyrosine and guanine the major products were 3-nitrotyrosine, 3, 5-dinitrotyrosine, 8-hydroxyguanine and 8-nitroguanine. These compounds have been used as indicators for the presence of peroxynitrite in previous studies. When PAN interacted with phenylalanine, the products were 3-nitrotyrosine, 4-nitrophenylalanine, p-tyrosine, o-tyrosine and m-tyrosine. 5-Hydroxytryptophan is produced from the reaction of PAN with tryptophan. Furthermore, the formation of nitrated tyrosines was also found in the PAN-treated HL-60 cells. A high yield of dityrosine was formed when PAN and peroxynitrite were reacted with tyrosine, probably through free radical oxidation. We also found that peroxynitrite and PAN are similar in their oxidizing activity. From these findings, we suggest that peroxynitrite may be considered as the reactive intermediate of PAN.

Inhibition of xanthine oxidase and suppression of intracellular reactive oxygen species in HL-60 cells by theaflavin-3,3'-digallate, (-)-epigallocatechin-3-gallate, and propyl gallate

The inhibitory effects of five tea polyphenols, namely theaflavin (TF1), theaflavin-3-gallate (TF2), theaflavin-3,3'-digallate (TF3), (-)-epigallocatechin-3-gallate (EGCG), and gallic acid, and propyl gallate (PG) on xanthine oxidase (XO) were investigated. These six antioxidant compounds reduce oxidative stress. Theaflavins and EGCG inhibit XO to produce uric acid and also act as scanvengers of superoxide. TF3 acts as a competitive inhibitor and is the most potent inhibitor of XO among these compounds. Tea polyphenols and PG all have potent inhibitory effects (>50%) on PMA-stimulated superoxide production at 20 approximately 50 microM in HL-60 cells. Gallic acid (GA) showed no inhibition under the same conditions. At 10 microM, only EGCG, TF3, and PG showed significant inhibition with potency of PG > EGCG > TF3. The superoxide scavenging abilities of these six compunds are as follows: EGCG > TF2 > TF1 > GA > TF3 > PG. PG was the most potent inhibitor of PMA-stimulated H(2)O(2) production in HL-60 cells. The order of H(2)O(2) scavenging ability was TF2 > TF3 > TF1 > EGCG > PG > GA. Therefore, the antioxidative activity of tea polyphenols and PG is due not only to their ability to scavenge superoxides but also to their ability to block XO and related oxidative signal transducers.

Cecal volvulus: report of seven cases and literature review

BACKGROUND

Cecal volvulus is an abdominal emergency and delay in its diagnosis and treatment can result in severe complications. We reviewed these cases in order to increase the understanding of cecal volvulus (CV) to promote early diagnosis and better management.

METHODS

In this retrospective study of seven patients (all male; mean age +/- standard deviation, 63.4 +/- 17.3 years) over a 16-year period, we reviewed radiographs, for diagnostic accuracy, and the results of surgical procedures for better future management.

RESULTS

The symptoms of CV related to obstruction had a mean of duration of 6.85 days (range, 2-20 days). The preoperative diagnosis rate was 57.1%. Three types of CV (bascule, clockwise and counterclockwise) were found. There were three treatment failures resulting in two deaths. There were two cases of metachronous volvulus, one in the sigmoid colon and one in the small intestine.

CONCLUSIONS

Resection is indicated for gangrene or perforation and is highly suggested in underlying bowel disease or recurrent operative procedures. For uncomplicated viable CV, cecopexy provides fair results. Metachronous volvulus should always be considered when obstruction recurs.

In vitro relaxation of rabbit and human internal anal sphincter by rutaecarpine, an alkaloid isolated from Evodia rutaecarpa

Rutaecarpine, a compound extracted from the Chinese medicinal herb Evodia rutaecarpa, has been shown to possess relaxing action on vascular smooth muscle from rat thoracic aorta. The internal anal sphincter is a specialized smooth muscle regulating important anorectal physiology. To investigate the effect and underlying mechanisms of rutaecarpine on internal anal sphincter, muscle strips from rabbit internal anal sphincter were used. The results showed that rutaecarpine (1 x 10(-10) M to 1 x 10(-4) M) produced a concentration-dependent muscular relaxation effect in our preparations, which were precontracted with acetylcholine. This muscular relaxation effect was not affected by treatment with L-N(G)-nitro-arginine methyl ester (a nitric oxide synthase inhibitor), methylene blue (a guanylate cyclase inhibitor), N-ethylmaleimide (an adenylate cyclase inhibitor), or by removal of the mucosa and submucosa tissue. Pretreatment with nifedipine (a calcium channel blocker) or extracellular Ca+2 removal by ethylenediaminetetraacetic acid (EDTA) greatly attenuated the relaxation effect, suggesting that calcium ion might be involved. In experiments using strips from human internal anal sphincter, an even more prominent relaxation effect was shown. It is thus concluded that rutaecarpine caused relaxation on internal anal sphincter from rabbits and human subjects. The relaxation action was not related to NO-cGMP pathway, instead calcium ion might play an important role and shed insight into clinical implications for those anorectal disorders with hyperactive anal tone.

Constituents from the leaves of Aristolochia elegans

One new biphenyl ether, aristogin C (1), and two new porphyrins, aristophylls A (2) and B (3), as well as 11 known compounds, were isolated from the leaves of Aristolochia elegans. Their structures were elucidated according to the spectroscopic (NMR and MS) analyses or by comparison with literature values.

Racial/ethnic and educational differences in the estimated odds of recent nitrite use among adult household residents in the United States: an illustration of matching and conditional logistic regression

This article compares estimates of the relative odds of nitrite use obtained from weighted unconditional logistic regression with estimates obtained from conditional logistic regression after post-stratification and matching of cases with controls by neighborhood of residence. We illustrate these methods by comparing the odds associated with nitrite use among adults of four racial/ethnic groups, with and without a high school education. We used aggregated data from the 1994-B through 1996 National Household Survey on Drug Abuse (NHSDA). Difference between the methods and implications for analysis and inference are discussed.

Local somatothermal stimulation inhibits motility of the internal anal sphincter through nitrergic neural release of nitric oxide

PURPOSE

A somatoanal reflex had been demonstrated in our previous work. Because nitric oxide plays an important role in mediating relaxation of the internal anal sphincter, our purpose was to examine whether and how local somatothermal stimulation inhibits the function of the internal anal sphincter by stimulating nitric oxide release via nitrergic neurons and to elucidate the possible mechanism.

METHODS

The activity of the internal anal sphincter in anesthetized rabbits was measured by use of continuously perfused, open-tip manometric methods. Local somatothermal stimulation was achieved by applying an electroheating rod 1 cm away from the skin area at the right popliteal region. The responses were further manipulated by pre-treating the rabbits with agonists or antagonists linked to nitric oxide synthesis.

RESULTS

The motility of the internal anal sphincter before and during local somatothermal stimulation was significantly different (tonic pressure (mean +/-standard error of the mean), 5.4 +/- 0.3 vs. 4.9 +/- 0.3 mmHg, P = 0.0195; phasic pressure, 3.9 +/- 0.6 vs. 2.9 +/- 0.4 mmHg, P = 0.0002; frequency distribution of the phasic contractions (peak-to-peak interval), 28.9 +/- 3.7 vs. 65.3 +/- 10.4 seconds, P = 0.0001). The response began at approximately one minute after local somatothermal stimulation when the skin temperature was 41 +/- 0.3 degrees C. No anal response was observed when local somatothermal stimulation was applied at the control area. The local somatothermal stimulation-induced internal anal sphincter relaxation was not inhibited by pretreatment with atropine, propranolol, or phentolamine (tonic pressure, 5.8 +/- 1 vs. 5.2 +/- 0.8 mmHg, P = 0.038; phasic pressure, 4.2 +/- 0.9 vs. 3.1 +/- 0.6 mmHg, P = 0.020; peak-to-peak interval, 27.2 +/- 4.3 vs. 52.9 +/- 14.5 seconds, P = 0.043) but was completely blocked by pretreatment with a nitric oxide synthesis inhibitor. The effect of the nitric oxide synthesis inhibitor could be reversed by pretreatment with L-arginine (tonic pressure, 6 +/- 0.7 vs. 5.6 +/- 0.7 mmHg, P = 0.047; phasic pressure, 4.7 +/- 0.7 vs. 3.9 +/- 0.5 mmHg, P = 0.048; peak-to-peak interval, 23.8 +/- 3 vs. 33 +/- 3.7 seconds, P = 0.048), but not by D-arginine.

CONCLUSION

Local somatothermal stimulation inhibits internal anal sphincter motility through the activation of nonadrenergic noncholinergic neural release of nitric oxide. This procedure may represent a simplified approach for the treatment of anorectal diseases with hypofunction of the L-arginine/nitric oxide pathway. [Key words: Local somatothermal stimulation; Nitric oxide; Internal anal sphincter; Motility; Moxibustion] Jiang J-K, Chiu J-H, Lin J-K. Local somatothermal stimulation inhibits motility of the internal anal sphincter through nitrergic neural release of nitric oxide.

Suppression of lipopolysaccharide-induced nuclear factor-kappaB activity by theaflavin-3,3'-digallate from black tea and other polyphenols through down-regulation of IkappaB kinase activity in macrophages

We investigated the inhibition of IkappaB kinase (IKK) activity in lipopolysaccharide (LPS)-activated murine macrophages (RAW 264.7 cell line) by various polyphenols including (-)-epigallocatechin-3-gallate, theaflavin, a mixture of theaflavin-3 gallate and theaflavin-3'-gallate, theaflavin-3,3'-digallate (TF-3), pyrocyanidin B-3, casuarinin, geraniin, and penta-O-galloyl-beta-D-glucose (5GG). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other polyphenols. TF-3 strongly inhibited both IKK1 and IKK2 activity and prevented the degradation of IkappaBalpha and IkappaBbeta in activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. Furthermore, geraniin, 5GG, and TF-3 all blocked phosphorylation of IKB from the cytosolic fraction, inhibited nuclear factor-kappaB (NFkappaB) activity, and inhibited increases in inducible nitric oxide synthase levels in activated macrophages. These results suggest that TF-3 may exert its anti-inflammatory and cancer chemopreventive actions by suppressing the activation of NFkappaB through inhibition of IKK activity.

Suppression of transcription factor NF-kappaB activity by Bcl-2 protein in NIH3T3 cells: implication of a novel NF-kappaB p50-Bcl-2 complex for the anti-apoptotic function of Bcl-2

Bcl-2 can suppress apoptosis by controlling genes that encode proteins required for programmed cell death and by interference with peroxidative damage. Overexpression of Bcl-2 in NIH3T3 cells can prevent GSNO-induced (S-nitrosoglutathione-induced) apoptosis. The experimental results indicated that activation of NF-kappaB by GSNO is involved in inducing apoptosis. Surprisingly, we found that Bcl-2 delayed the release of IkB by formation of a Bcl-2-NF-kappaB complex (p50-p65-IkappaB) in the cytoplasm during cell apoptosis. Furthermore, a novel Bcl-2-p50 complex was found in the nucleus. These features were only observed in Bcl-2-transfected cells but not in the parental NIH3T3 cells. Overexpression of Bcl-2 suppressed the levels of c-myc, a target gene of NF-kappaB, and influenced the DNA-binding activity of NF-kappaB during GSNOinduced apoptosis. We suggest that the Bcl-2-p50 complex inhibits NF-kappaB DNA-binding activity by competing with the p65-p50 heterodimer for the DNA-binding site in the nucleus. Finally, it has been demonstrated that the anti-apoptotic potential of Bcl-2 may be attributed to its complexing with p50 in the nucleus that leads to blockage of nuclear gene expression.

Induction of apoptosis by lovastatin through activation of caspase-3 and DNase II in leukaemia HL-60 cells

Lovastatin, an HMG-CoA reductase inhibitor, was found to suppress growth and induce apoptosis in culture human promyelocytic leukaemic cell, HL-60. However, the mechanisms of lovastatin-induced apoptosis are still unclear. In this study, we attempted to elucidate the signal transduction pathway for lovastatin-induced apoptosis in HL-60 cells in a dose- and time-dependent manner. The features of this apoptosis were attenuated by the presence of mevalonate, a metabolic intermediate of cholesterol synthesis. Treatment of lovastatin caused a rapid release of mitochondrial cytochrome c into cytosol and subsequent induction of caspase-3, but not caspase-1 activity. Lovastatin also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP), and followed by the appearance of caspase activity and DNA fragmentation. Pretreatment with caspase-3 inhibitors, Ac-DEVD-CHO and Z-VAD-FMK, inhibited lovastatin induced caspase-3 activity and DNA fragmentation. Furthermore, we demonstrated that DNase II was involved in the DNA fragmentation induced by lovastatin. These results suggested that the mechanism of lovastatin induced HL-60 cells apoptosis through activation of caspase-3 and DNase II activities.

Curcumin-containing diet inhibits diethylnitrosamine-induced murine hepatocarcinogenesis

Curcumin has been widely used as a spice and coloring agent in foods. Recently, curcumin was found to possess chemopreventive effects against skin cancer, forestomach cancer, colon cancer and oral cancer in mice. Clinical trials of curcumin for prevention of human cancers are currently ongoing. In this study, we examine the chemopreventive effect of curcumin on murine hepatocarcinogenesis. C3H/HeN mice were injected i.p. with N-diethylnitrosamine (DEN) at the age of 5 weeks. The curcumin group started eating 0.2% curcumin-containing diet 4 days before DEN injection until death. The mice were then serially killed at the scheduled times to examine the development of hepatocellular carcinoma (HCC) and changes in intermediate biological markers. At the age of 42 weeks, the curcumin group, as compared with the control group (DEN alone), had an 81% reduction in multiplicity (0.5 versus 2.57) and a 62% reduction in incidence (38 versus 100%) of development of HCC. A series of intermediate biological markers were examined by western blot. While hepatic tissues obtained from the DEN-treated mice showed a remarkable increase in the levels of p21(ras), PCNA and CDC2 proteins, eating a curcumin-containing diet reversed the levels to normal values. These results indicate that curcumin effectively inhibits DEN-induced hepatocarcinogenesis in the mouse. The underlying mechanisms of the phenomenon and the feasibility of using curcumin in the chemoprevention of human HCC should be further explored.

Cancer chemoprevention by tea polyphenols

Tea is one of the most widely consumed beverages, second only to water. Many experimental researches in laboratory animals demonstrated that tea components had an inhibitory effect on carcinogenesis at a number of organ sites. The inhibitory effects of tea against carcinogenesis have been attributed to the biologic activities of the polyphenol fraction in tea. This review summarizes experimental data on chemopreventive effects of tea polyphenols in various tumor bioassay systems. Many laboratory studies have demonstrated the inhibitory effects of green tea polyphenols, especially (-)-epigallocatechin-3-gallate (EGCG), on carcinogenesis in animals models. The majority of these studies have been conducted in mouse skin tumor models, where tea polyphenols were used either as oral feeding in drinking water or in direct local application. Most studies used 12-O-tetradecanoylphorbol-13-acetate (TPA) or ultraviolet (UV) radiation as the tumor promoter and found anticarcinogenic effects caused by green tea polyphenols. Black tea was also found to be effective, although the activity was weaker than that of green tea in some experiments. Other studies showed that black tea polyphenols-theaflavins exhibited stronger anticarcinogenic activity than did EGCG. Caffeine in tea was also important for tea to prevent tumorigenesis. The molecular mechanisms of the cancer chemopreventive effects of tea polyphenols are not completely understood. They are most likely related to the mechanisms of biochemical actions of tea polyphenols, which include antioxidative activities, modulation of xenobiotic metabolite enzymes and inhibition of tumor promotion. In addition, we have also proposed that tea polyphenols function as cancer chemopreventive agents through modulation of mitotic signal transduction. However, the molecular mechanisms involved in this modulation need further investigation.

Recent studies on the biofunctions and biotransformations of curcumin

Curcumin is a major component of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animals as indicated by its ability to block colon tumor initiation by azoxymethane and skin tumor promotion induced by phorbol ester TPA. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase. Curcumin is also a potent inhibitor of protein kinase C, EGF-receptor tyrosine kinase and IkappaB kinase. Subsequently, curcumin inhibits the activation of NFkappaB and the expressions of c-jun, c-fos, c-myc and iNOS. It is proposed that curcumin may suppress tumor promotion through blocking signal transduction pathways in the target cells. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently were converted to monoglucuronide conjugates. These results suggest that curcumin-glucuronide, dihydro-curcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are major metabolites of curcumin in mice.

Preoperative carcinoembryonic antigen level as an independent prognostic factor in colorectal cancer: Taiwan experience

BACKGROUND

Preoperative carcinoembryonic antigen (CEA) level is considered as a factor predictive of survival in colorectal cancer patients. Patients with normal (<5 ng/ml) or lower preoperative CEA levels were reported to have significantly longer survival. This study was carried out in an effort to evaluate the prognostic significance of preoperative CEA levels of patients with colorectal cancer in Taiwan.

METHODS

Between 1990 and 1994, 218 patients with histologically confirmed colorectal cancers were evaluated retrospectively at the Veterans General Hospital-Taipei. All the patients had undergone potentially curative surgery. Patients with metastatic diseases were not included. 5-Fluorouracil-based adjuvant chemotherapy was administered if the patients had Dukes' C disease. Reference to the Dukes' classification was according to the classical criteria described in 1932 for carcinoma of the rectum and adapted for use in colonic tumors. Data on gender, age, degree of tumor differentiation, location of the tumor, tumor size, lymph node metastasis, penetration of the bowel wall and preoperative CEA levels were analyzed to determine their association with survival. Blood samples for CEA measurement were taken a few days before operation and were analyzed using the radioimmunoassay method. Multivariate analysis by Cox's proportional hazards regression model was performed to determine the most important predictors of survival among all of the possible variables.

RESULTS

By univariate analysis, the size of the tumor (p = 0.012), lymph node metastases (p = 0.007), penetration of the bowel wall (p < 0.001) and preoperative CEA levels (p < 0.001) were found to be significant prognostic factors, while gender, age, degree of tumor differentiation and location of the tumor were not significant. By multivariate Cox analysis, lymph node metastases (p = 0.003), penetration of the bowel wall (p = 0.0001) and preoperative CEA levels (p = 0.0001) were found to be independent prognostic factors in colorectal cancer patients.

CONCLUSIONS

The data from our study indicate that in addition to lymph node metastases and penetration of the bowel wall, the preoperative CEA levels are also an independent prognostic factor in non-metastatic colorectal cancer patients after curative surgery. This could serve as an appropriate modification to the initial Dukes' scheme in colorectal cancer.

Induction of apoptosis by S-nitrosoglutathione and Cu2+ or Ni2+ ion through modulation of bax, bad, and bcl-2 proteins in human colon adenocarcinoma cells

In this study, the amount of S-nitrosoglutathione (GSNO) was measured spectrophotometrically at 334 nm. A spontaneous decrease in absorbency at 334 nm was detected when GSNO was exposed to 37 degrees C and a high pH (pH 8.0). We investigated the catalytic roles of various metal ions on the decomposition of GSNO. The degradation of GSNO (0.5 mM) was enhanced by the presence of Cu(2+) and Ni(2+) ions. The amount of nitric oxide (NO) released from GSNO degradation was estimated by the Griess reaction based on nitrite accumulation. The results indicated that nitrite production was elevated at least twofold in the presence of Cu(2+). Our study further indicated that Cu(2+) enhanced GSNO-induced apoptosis in human colon adenocarcinoma HT 29 cells. We also found that copper ions modulated the expression of bad, bax, and bcl-2 in GSNO-treated HT 29 cells. The levels of bax and bad proteins in treated cells were significantly elevated about fourfold to sixfold when compared with mock-treated cells 24 h after combined treatment with GSNO plus Cu(2+) or Ni(2+). On the other hand, significant inhibition of bcl-2 occurred in HT 29 cells with simultaneous treatment of GSNO with Cu(2+) (or Ni(2+)). It seemed that Cu(2+) and Ni(2+) can enhance the decomposition of GSNO, which liberates NO to activate the pathways. Our results demonstrated that the apoptotic effects induced by GSNO were promoted by Ni(2+) and Cu(2+) through two different mechanisms: depletion of intracellular glutathione and triggering of NO release from GSNO, which then promotes NO-induced apoptosis in human cells.