A rare cause of mesenteric ischemia: celiac axis compression syndrome

Mesenteric ischemia is an uncommon etiology of abdominal pain. Celiac axis compression syndrome is an extremely rare cause of mesenteric ischemia. The primary pathological mechanism is the external compression of the celiac trunk by median arcuate ligament. The clinical manifestation of celiac axis compression syndrome includes postprandial pain, diarrhea, and body weight loss. The diagnosis of this disease is usually difficult and depends on the angiography findings. For treatment, only percutaneous transluminal angioplasty and surgical intervention have been suggested in reviews in the literature. We, herein, report an unusual case of celiac axis compression syndrome and also review the literature pertaining to this disease.

Phase II study of weekly vinorelbine and 24-h infusion of high-dose 5-fluorouracil plus leucovorin as first-line treatment of advanced breast cancer

We prospectively investigated the efficacy and safety of combining weekly vinorelbine (VNB) with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV) in the treatment of patients with advanced breast cancer (ABC). Vinorelbine 25 mg m⁻² 30-min intravenous infusion, and high-dose 5-FU 2600 mg m⁻² plus LV 300 mg m⁻² 24-h intravenous infusion (HDFL regimen) were given on days 1 and 8 every 3 weeks. Between June 1999 and April 2003, 40 patients with histologically confirmed recurrent or metastatic breast cancer were enrolled with a median age of 49 years (range: 36–68). A total of 25 patients had recurrent ABC, and 15 patients had primary metastatic diseases. The overall response rate for the intent-to-treat group was 70.0% (95% CI: 54–84%) with eight complete responses and 20 partial responses. All 40 patients were evaluated for survival and toxicities. Among a total of 316 cycles of VNB–HDFL given (average: 7.9: range: 4–14 cycles per patient), the main toxicity was Gr3/4 leucopenia and Gr3/4 neutropenia in 57 (18.0%) and 120 (38.0%) cycles, respectively. Gr1/2 infection and Gr1/2 stomatitis were noted in five (1.6%) and 59 (18.7%) cycles, respectively. None of the patients developed Gr3/4 stomatitis or Gr3/4 infection. Gr2/3 and Gr1 hand–foot syndrome was noted in two (5.0%) and 23 (57.5%) patients, respectively. Gr1 sensory neuropathy developed in three patients. The median time to progression was 8.0 months (range: 3–25.5 months), and the median overall survival was 25.0 months with a follow-up of 5.5 to 45+ months. This VNB–HDFL regimen is a highly active yet well-tolerated first-line treatment for ABC.

One-year follow-up study of Helicobacter pylori eradication rate with 13C-urea breath test after 3-d and 7-d rabeprazole-based triple therapy

AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori(H pylori)-infected active peptic ulcers.

METHODS: We prospectively studied 115 consecutive patients with H pylori-infected active peptic ulcers. H pylori infection was confirmed if any two of H pylori DNA, histology, and rapid urease test were positive. Patients were assigned to either an open-labeled 3-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d., or 7-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d. Subsequently, all patients received oral rabeprazole 20 mg once daily until the 8^th wk. Three months after therapy, all patients were followed-up endoscopically for the peptic ulcer, H pylori DNA, histology, and rapid urease test. One year after therapy, H pylori infection was tested using the ¹³C-urea breath test.

RESULTS: The ulcer healing rates 3 mo after therapy were 81.0% vs 75.4% for the 3-d and 7-d groups [intention-to-treat (ITT) analysis, P = 0.47] respectively, and 90.4% vs 89.6% for the 3-d and 7-d groups [per-protocol (PP) analysis, P = 0.89] respectively. The eradication rates 3 mo after therapy were 75.9% vs 73.7% for the 3-d and 7-d groups (ITT, P = 0.79) respectively, and 84.6% vs 87.5% for the 3-d and 7-d groups (PP, P = 0.68) respectively. One year after therapy, seventy-five patients returned to receive the ¹³C-urea breath test, and the eradication rates were 78.4% vs 81.6% in 3-d and 7-d groups (PP, P = 0.73) respectively.

CONCLUSION: Our study showed the eradication rates against H pylori infection 3 and 12 mo after triple therapy were not different between the 3-d and 7-d rabeprazole-based groups. Therefore, the 3-d rabeprazole-based triple therapy may be an alternative treatment for peptic ulcers with H pylori infection.

Gastric bleeding due to graft-vs-host disease: discrepancy between endoscopic and histologic assessment

Gastric bleeding due to graft-vs-host-disease (GVHD) is rare after allogeneic hematopoietic stem cell transplantation, and the interrelationship between endoscopic and histologic assessment has not been well studied. Four patients with documented gastric bleeding due to GVHD were evaluated retrospectively. The endoscopic findings varied markedly and included mild mucosal edema with focal erythema, diffuse erythema with mucosal oozing, and diffuse polypoid indurations with multiple bleeding ulcerations. The histologic features of endoscopic biopsy specimens also varied from scattered apoptotic epithelial cells in one end to denudation of the epithelium with crypt necrosis in the other. The endoscopic findings could not accurately predict the histologic grading of GVHD. Nevertheless, gastric bleeding resolved in 3 patients with increasing intensity of immunosuppression. There was significant disparity between the endoscopic and histologic assessment of the severity of GVHD, and careful adjustment of immunosuppressive therapy might be warranted.

Helicobacter pylori infection in patients with ulcer recurrence after partial gastrectomy

BACKGROUND/AIMS

Recurrent ulceration of the stomach occurs in some patients after surgery for peptic ulcer disease. The aim of this study is to evaluate the association of Helicobacter pylori infection with ulcer recurrence in patients after partial gastrectomy due to peptic ulcer disease.

METHODOLOGY

A total of 186 patients after partial gastrectomy with Billroth I or Billroth II anastomosis presenting with dyspepsia or bleeding were included. An ulcer recurrence was documented by endoscopic examination. Biopsy specimens were taken from the remnant gastric bodies in all patients. H. pylori infection was diagnosed by either a positive biopsy urease test or the presence of the microorganism on histology.

RESULTS

Eighty-three (44.6%) patients among the 186 patients had recurrent ulcers. H. pylori infection was found in 29 (36%) patients in the ulcer group and 42 (41%) patients in the non-ulcer group. The incidence of H. pylori infection did not differ significantly between the two groups (P>0.05).

CONCLUSIONS

H. pylori infection may not play an important role in the pathogenesis of recurrent ulcer after partial gastrectomy. Other factors should be studied further.

A feasibility study on the predictive emission monitoring system applied to the Hsinta power plant of Taiwan Power Company

The continuous emission monitoring system (CEMS) can monitor flue gas emissions continuously and instantaneously. However, it has the disadvantages of enormous cost, easily producing errors in sampling periods of bad weather, lagging response in variable ambient environments, and missing data in daily zero and span tests and maintenance. The concept of a predictive emission monitoring system (PEMS) is to use the operating parameters of combustion equipment through thermodynamic or statistical methods to construct a mathematic model that can predict emissions by a computer program. The goal of this study is to set up a PEMS in a gas-fired combined cycle power generation unit at the Hsinta station of Taiwan Power Co. The emissions to be monitored include nitrogen oxides (NOx) and oxygen (O2) in flue gas. The major variables of the predictive model were determined based on the combustion theory. The data of these variables then were analyzed to establish a regression model. From the regression results, the influences of these variables are discussed and the predicted values are compared with the CEMS data for accuracy. In addition, according to the cost information, the capital and operation and maintenance costs for a PEMS can be much lower than those for a CEMS.

Using non-invasive radionuclide imaging to detect esophagitis in patients with gastroesophageal reflux disease

BACKGROUND/AIMS

The aim of our study was to evaluate technetium-99m tetrofosmin SPECT (single photon emission computed tomography) of the chest as a potential non-invasive method to evaluate esophagitis among gastroesophageal reflux disease patients.

METHODOLOGY

In this study, we used non-invasive radionuclide imaging technetium-99m tetrofosmin chest SPECT to detect and grade esophagitis in 60 patients with gastroesophageal reflux disease.

RESULTS

Based on the endoscopic findings according to the Savary-Miller system, the sensitivity, specificity, and accuracy rates of technetium-99m tetrofosmin chest SPECT in detecting esophagitis were 95.2%, 72.2%, and 88.3%, respectively. The agreement between the endoscopic and technetium-99m tetrofosmin chest SPECT findings was evaluated and found to be good (kappa: 0.633, p < 0.001).

CONCLUSIONS

Non-invasive technetium-99m tetrofosmin chest SPECT has excellent sensitivity and good accuracy as a screen for esophagitis among gastroesophageal reflux disease patients.

Differentiation of low-grade gastric MALT lymphoma and high-grade gastric MALT lymphoma: the clinical value of Ga-67 citrate scintigraphy--a pilot study

Ga-67 citrate scintigraphy has been routinely and extensively used to evaluate non-Hodgkin's lymphoma (NHL) for more than 20 years. Gastric lymphoma of mucosa-associated lymphoid tissue (MALT) is by far the most common extranodal primary NHL. Gastric MALT lymphoma can be classified as low-grade (LG) or high-grade (HG). Low-grade gastric MALT lymphoma can be cured by eradication of Helicobacter pylori; but radiotherapy and/or chemotherapy and/or surgery are the major methods of treatment for the HG gastric MALT lymphoma. However, it is difficult to differentiate these two groups by clinical parameters and endoscopic findings. The purpose of this study was to determine whether Ga-67 citrate scintigraphy can distinguish the LG gastric MALT lymphoma from the HG gastric MALT lymphoma. Twenty-one patients (11 men and 10 women ranging in age from 38 to 83 years) with histologically confirmed gastric MALT lymphoma were enrolled. Twelve patients had LG and nine patients had HG. All 21 patients underwent Ga-67 citrate scintigraphy before treatment. The results of Ga-67 citrate scintigraphy were classified as positive or negative. In the LG group, nine patients had negative results and three patients had positive results. In the HG group of nine patients, all patients had positive results. Among the three patients who had positive results in the LG group, the uptake of gastric MALT lymphoma was lower than that of the liver. The Ga-67 citrate scintigraphy is of good clinical value for the differentiation of the LG gastric MALT lymphoma and the HG gastric MALT lymphoma. We think that the major value of Ga-67 citrate scintigraphy will be in following the patients with HG gastric MALT lymphoma after treatment to assess response of therapy and to detect possible recurrence and perhaps in determining transformation from the LG to HG gastric MALT lymphoma. However, further investigation is needed to understand the relationship between the uptake of Ga-67 citrate in gastric MALT lymphoma and transformation.

Microbial iron respiration can protect steel from corrosion

Microbiologically influenced corrosion (MC) of steel has been attributed to the activity of biofilms that include anaerobic microorganisms such as iron-respiring bacteria, yet the mechanisms by which these organisms influence corrosion have been unclear. To study this process, we generated mutants of the iron-respiring bacterium Shewanella oneidensis strain MR-1 that were defective in biofilm formation and/or iron reduction. Electrochemical impedance spectroscopy was used to determine changes in the corrosion rate and corrosion potential as a function of time for these mutants in comparison to the wild type. Counter to prevailing theories of MC, our results indicate that biofilms comprising iron-respiring bacteria may reduce rather than accelerate the corrosion rate of steel. Corrosion inhibition appears to be due to reduction of ferric ions to ferrous ions and increased consumption of oxygen, both of which are direct consequences of microbial respiration.

Importance of early phase insulin secretion to intravenous glucose tolerance in subjects with type 2 diabetes mellitus

Insulin secretion is impaired in type 2 diabetes with the early response being essentially absent. The loss of this early insulin secretion is hypothesized to be important in the deterioration of glucose tolerance. To determine whether enhancement of the early-phase insulin response can enhance glucose tolerance, we administered 1) 120 mg nateglinide, an insulinotropic agent that enhances early insulin secretion; 2) 10 mg glyburide, which enhances the later phases of insulin secretion; or 3) placebo in random order to 21 subjects with type 2 diabetes (14 males and 7 females; aged 59.2 +/- 2.1 yr, x +/- SEM; body mass index 29.7 +/- 1.0 kg/m(2); fasting plasma glucose 8.1 +/- 0.1 mM). beta-Cell function was quantified as the incremental area under the curve for different time periods for the 5 h following iv glucose administration and glucose tolerance as the glucose disappearance constant (Kg) from 10 to 60 min. Insulin release commenced immediately after nateglinide administration, even before glucose injection, but this was not observed with glyburide. Both nateglinide and glyburide enhanced glucose-induced insulin release, compared with placebo (area under the curve -15-300 min: nateglinide 23,595 +/- 11,212 pM/min, glyburide 54,556 +/- 15,253 pM/min, placebo 10,242 +/- 2,414 pM/min). The profiles of insulin release demonstrated significant enhancement of release between -15 and 30 min for nateglinide, compared with glyburide and between 60 and 300 min for glyburide over nateglinide. Kg increased by 15% with nateglinide (0.87 +/- 0.04%/min), but it did not increase significantly with glyburide (0.79 +/- 0.04%/min), compared with placebo (0.76 +/- 0.04%/min). The enhancement of insulin release by glyburide resulted in a lower minimal glucose concentration with glyburide (3.8 +/- 0.2 mM), compared with nateglinide (5.0 +/- 0.2 mM) and placebo (5.9 +/- 0.2 mM). Thus, enhancement of the early phase of insulin secretion improves iv glucose tolerance, whereas delaying it by 30 min results in a slower rate of glucose disappearance for the first 2 h after iv glucose administration. Further, the differences in the kinetics of nateglinide and glyburide action results in continued insulin release with glyburide despite the fact that glucose levels have returned to basal, thus resulting in a further reduction in glucose levels and a lower nadir.

Estimation for paired binomial data with application to radiation therapy

We compare and contrast several different methods for estimating the effect of treatment when responses are paired binomial observations. The ratio of binomial probabilities is the parameter of interest, while the binomial probabilities are nuisance parameters which may vary between pairs. The application is a meta-analysis of the treatment of rectal cancer, with observations in each study indicating the number of recurrences of the cancer in each of two groups, one with radiation therapy and one without. The ratio of the probabilities of recurrence in the radiation to non-radiation groups is of substantive interest, and is modelled as a logistic or complementary log-log function of an unknown linear combination of the covariates. The three methods we consider are maximum likelihood, a Bayesian approach and an approach based on estimating equations. For the MLE and Bayesian approach the potentially large number of nuisance parameters are estimated together with the parameters of interest, whereas for the estimating equation approach only the parameters of interest are estimated. A simulation study is performed to compare the methods and evaluate the impact of overdispersion.

Solution structure of a Kunitz-type chymotrypsin inhibitor isolated from the elapid snake Bungarus fasciatus

Bungarus fasciatus fraction IX (BF9), a chymotrypsin inhibitor, consists of 65 amino acid residues with three disulfide bridges. It was isolated from the snake venom of B. fasciatus by ion-exchange chromatography and belongs to the bovine pancreatic trypsin inhibitor (BPTI)-like superfamily. It showed a dissociation constant of 5.8 x 10(-8) m with alpha-chymotrypsin as measured by a BIAcore binding assay system. The isothermal titration calorimetry revealed a 1:1 binding stoichiometry between this inhibitor and chymotrypsin and apparently no binding with trypsin. We further used CD and NMR to determine the solution structure of this venom-derived chymotrypsin inhibitor. The three-dimensional NMR solution structures of BF9 were determined on the basis of 582 restraints by simulated annealing and energy minimization calculations. The final set of 10 NMR structures was well defined, with average root mean square deviations of 0.47 A for the backbone atoms in the secondary structure regions and 0.86 A for residues The side chains of Phe(23), Tyr(24), Tyr(25), Phe(35), and Phe(47) exhibited many long-range nuclear Overhauser effects and were the principal components of the hydrophobic core in BF9. To gain insight into the structure-function relationships among proteins in the BPTI-like superfamily, we compared the three-dimensional structure of BF9 with three BPTI-like proteins that possess distinct biological functions. These proteins possessed similar secondary structure elements, but the loop regions and beta-turn were different from one another. Based on residues at the functional site of each protein, we suggest that the flexibility, rigidity, and variations of the amino acid residues in both the loop and beta-turn regions are related to their biological functions.

The p53 codon 249 mutant--derived from human functional adrenal tumors--can modify the cell shape of normal adrenocortical transfected cells

Our previous study has indicated that p53 gene mutation occurred in 73% of human functional adrenal tumors, and the mutation hot spots were focused on codons 100, 102 (exon 4), and 249 (exon 7). Furthermore, a transcriptional activity study revealed that the mutant p53 protein derived from human functional adrenal tumors lost 90% transcriptional activity and the ability to bind with the p53 sequence. In order to investigate the influence of the mutant protein extracted from adrenocortical tumors on normal adrenal cells, we first cloned p53 cDNA from the human primary aldosteronism and constituted it with isopropyl thiogalactoside (IPTG) inducible expression vector as recombinant plasmid. The recombinant plasmid was then transfected to normal bovine adrenocortical cells through electroporation. The results showed that the p53 protein mutations at codons 100 and 102 could neither affect the cell morphology nor enable cell growth on the soft agar. In addition, no significant difference was found in cortisol level between the p53 transfected and the control cells. On the other hand, cell morphological changes and cell proliferation rate increase were observed when we used IPTG to induce the expression of the p53 protein, which mutated at codon 249, in adrenocortical cells. The cell morphology changes included less flattened and decreased elongation when compared to non-transfected cells. However, the cortisol level in transfected cells was not affected by the p53 mutants. Taken together, we concluded that the mutant p53 protein indeed participates in adrenal carcinogenesis; however, it has no influence on hormone production and secretion.

Population pharmacokinetics of everolimus in de novo renal transplant patients: impact of ethnicity and comedications

BACKGROUND

Everolimus is a macrolide immunosuppressant intended for acute rejection prophylaxis after kidney transplantation.

METHODS

A total of 5260 blood samples were collected in the context of two randomized, double-blind, multicenter efficacy trials in 673 patients over a 6-month period after kidney transplantation. The data were evaluated in a nonlinear mixed-effects model. The influence of demographic characteristics (age, weight, sex, and ethnicity) and of comedications on everolimus exposure was explored.

RESULTS

For a reference 44-year-old, 71-kg Caucasian kidney allograft recipient receiving everolimus as part of a cyclosporine (INN, ciclosporin)-prednisone immunosuppressive regimen, the absorption rate constant was 6.07 h(-1) (standard error [SE], 0.70 h(-1)), the apparent clearance was 8.8 L/h (SE, 0.2 L/h), and the apparent central distribution volume was 110 L (SE, 5 L). There were no clinically relevant influences of age, weight, or sex on clearance. No significant difference in clearance was detected for Asian patients, whereas black patients had an average clearance that was 20% higher than that of nonblack patients. Patients concomitantly receiving erythromycin or azithromycin had an average 19% lower clearance. One patient receiving itraconazole had a 74% reduction in clearance. After we accounted for covariates, the remaining interindividual variability in clearance was 27% and the variability for distribution volume was 36%. The combined intraindividual and assay/measurement residual error in everolimus blood concentrations was 31%.

CONCLUSIONS

Dose adjustment of everolimus on the basis of weight does not appear necessary. Black patients may need a higher dose to achieve exposure that is similar to that of nonblack patients. Concomitant administration of potent inhibitors of the cytochrome P450 isozyme CYP3A may reduce everolimus clearance and increase its blood concentrations.

Pathogens in the middle ear effusion of children with persistent otitis media: implications of drug resistance and complications

Acute otitis media (AOM) is the most common disease for which pediatricians prescribe antimicrobial agents. Middle ear fluid were collected from 243 children with AOM that failed to respond to a previous course of antimicrobial therapy and who had then received myringotomy from September 1997 through August 1999. Bacterial cultures were done and antimicrobial susceptibilities were analyzed. Streptococcus pneumoniae (21.8%) was the most common causative organism, followed by Haemophilus influenzae (10.2%), Staphylococcus aureus (7%), and Pseudomonas aeruginosa (1.8%), while Moraxella catarrhalis (0.7%) and group A beta-hemolytic streptococcus (0.2%) were rarely isolated. In patients whose condition failed to improve after a course of antibiotic treatment, drug resistance became a serious problem. Fourteen percent of the patients in this series had complications, which included recurrent AOM, persistent middle ear effusion necessitating ventilation tube insertion, hearing impairment, mastoiditis, meningitis, chronic otitis media, brain abscess, and sepsis. Possible risk factors such as young age, male sex, underlying diseases, and a culture of S. pneumoniae or H. influenzae were not significantly associated with an increased incidence of complications. More stringent diagnosis and the correct choice of antibiotic treatment combined with the introduction of potential virus and bacterial vaccines are promising ways to reduce the morbidity of AOM in children.

Abamectin effects on aspartate aminotransferase and nitric oxide in rats

Abamectin is widely used as an insecticide and an anthelmintic. A previous report indicated that abamectin was used to commit suicide and led to death in Taiwan. This investigation focused on the toxicological effects of abamectin on serum aspartate aminotransferase (AST) and nitrate/nitrite (NO) levels in rats. After rats were gavaged with abamectin ranging from 1 to 20 mg/kg/body weight, AST and NO levels were examined within 12 h. AST and NO levels were elevated in abamectin-dosed rats in a dose-dependent manner. The least increase of AST corresponded to the highest enhancement of NO release at 6 h. A negative correlation coefficient (r=-0.55) between AST and NO was found. Both NG-nitro-L-arginine-methyl ester and aminoguanidine, inhibitors of nitric oxide synthase, increased the AST level induced by abamectin. These findings suggest that NO may be involved in the alteration of AST release induced by abamectin in rats.

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.

Analysis of 200 food items for benzo[a]pyrene and estimation of its intake in an epidemiologic study

Animal studies have shown that dietary intake of benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), causes increased levels of tumors at several sites, particularly in the upper gastrointestinal tract. However, the role of dietary intake of BaP and cancer in humans is not clear. We created a BaP database of selected food products that could be linked to Food Frequency Questionnaires (FFQs) to estimate BaP intake. BaP levels were measured for each food line-item (composite samples) which consisted of a variety of foods in a FFQ. Composite sample parts were derived from the Second National Health and Nutrition Examination Survey (NHANES II) which represents the most common food items consumed by the general population. Meat samples were cooked by different techniques in controlled conditions, and by various restaurants and fast-food chains. Non-meat products were purchased from the major national supermarket chains. The quantities of BaP were measured using a thin-layer chromatography (TLC)/spectrofluorometer technique and were highly correlated with both BaP (r=0.99) [corrected] and sum of carcinogenic PAH (r=0.98) measured by HPLC technique. We linked our database to the results from a FFQ and estimated the daily BaP intake of various food items in 228 subjects in the Washington, DC metropolitan area. The highest levels of BaP (up to about 4 ng BaP/g of cooked meat) were found in grilled/barbecued very well done steaks and hamburgers and in grilled/barbecued well done chicken with skin. BaP concentrations were lower in meats that were grilled/barbecued to medium done and in all broiled or pan-fried meat samples regardless of doneness level. The BaP levels in non-meat items were generally low. However, certain cereals and greens (e.g. kale, collard greens) had levels up to 0.5 ng/g. In our population, the bread/cereal/grain, and grilled/barbecued meat, respectively, contributed 29 and 21 percent to the mean daily intake of BaP. This database may be helpful in initial attempts to assess dietary BaP exposures in studies of cancer etiology.

Significantly increased cortisol secretion in normal adrenocortical cells transfected with K-ras mutants derived from human functional adrenocortical tumors

Our previous study showed that the mutation hotspots of the K-ras proto-oncogene in human functional adrenocortical tumors are in codons 15, 16, 18, and 31, thus differing from the sites in other tumors. In addition, analyzing the K-Ras protein by a recombinant DNA technique showed that the activity of endogenic GTPase and the GTPase-activating protein (GAP)-binding ability were significantly decreased in patients with these tumors. The aim of this study was to understand whether those K-ras mutants, which were found only in human adrenocortical tumors, play an important role in these tumors. Thus, the mutant K-ras cDNA was constructed with mammalian expression vectors and transfected into normal adrenocortical cells. The amount of cortisol secreted by the transfected cells was 20 to 30 times that of normal cells. Furthermore, Northern blot analysis revealed that the expression of the three steroidogenesis-related genes P450(scc) (cholesterol side-chain cleavage enzyme), P450(C17) (17alpha-hydroxylase/17, 20-lyase), and P450(C21) (steroid 21-hydroxylase) gene increased in the transfected cells. The K-ras oncogene significantly increases cortisol secretion by normal adrenocortical cells.

A pilot study of AFL-T (doxorubicin, 5-fluorouracil, leucovorin, and tamoxifen) combination chemotherapy for hormone-refractory prostate cancer

BACKGROUND

Tamoxifen had been used to treat advanced prostate cancer with limited success. In vitro data suggested that tamoxifen could enhance the cytotoxic effect of chemotherapeutic agents, including doxorubicin, on prostate cancer cell lines. We applied this observation into a phase II trial for patients with hormone refractory prostate cancer (HRPC).

PATIENTS AND METHODS

The AFL-T regimen consisted of doxorubicin 30 mg/m2/day on day 1; 5-FU 2,000 mg/m2/day 24-hour infusion and leucovorin 200 mg/m2/day 24-hour infusion on days 15 and 29; tamoxifen 50 mg/m2 four times daily on days 1, 2, 16, 17, 30, and 31. The protocol was designed to be of low dose-intensity and tolerable to most HRPC patients who may have reduced bone marrow reserve and poor renal function. Between Feb. 1994 and April 1999, 17 patients (median age 67, range 60-81) with HRPC were enrolled. Extensive hormonal manipulations had been done prior to the chemotherapy. Three patients had measurable diseases, 14 had only bone metastases, and all had elevated PSA levels (median 498 ng/ml, range 7.4-3,970 ng/ml).

RESULTS

All 17 patients were eligible for analysis of toxicity. ECOG Grade III/IV leukopenia and thrombocytopenia occurred in 1 and 3 patients, respectively. There was no febrile neutropenia; there was no treatment-related mortality. Grade III/IV nausea, vomiting, mucositis, and diarrhea were noted in 0, 0, 1 and 0 patient, respectively. There was no venous thrombosis. One partial response, 1 stable disease, and 1 progressive disease were found in the three patients with measurable lesions. Eleven of the 17 patients (64.7%, 95% confidence interval: 41-88%) who were eligible for the evaluation of PSA response (PSA decrease > 50% for at least 6 weeks) were responders. The median overall and progression-free survivals were 13 and 7 months, respectively. Seventy-six percent of patients showed decreased analgesic usage or enhanced performance status.

CONCLUSION

AFL-T, that has a low toxicity profile, is comparable to most other active regimens in terms of the PSA response rate. Randomized trials are needed to determine if there exists a survival benefit for patients with HRPC.