A Retrospective Analysis of Biliary Tract Cancer Patients Presented to the Molecular Tumor Board at the Comprehensive Cancer Center Munich.

BACKGROUND AND OBJECTIVE: With the rising importance of precision oncology in biliary tract cancer (BTC), the aim of this retrospective single-center analysis was to describe the clinical and molecular characteristics of patients with BTC who underwent comprehensive genomic profiling (CGP) and were discussed in the CCCMunichLMU molecular tumor board (MTB). PATIENTS AND METHODS: In this single-center observational study, we included BTC patients with intrahepatic cholangiocarcinoma (iCCA), extrahepatic CCA (eCCA), and gallbladder cancer (GB), who had been discussed in the institutional MTB from May 29, 2017, to July 25, 2022. Patients were followed up until 31 January 2023. Data were retrospectively collected by review of medical charts, and MTB recommendation. RESULTS: In total, 153 cases were registered to the MTB with a median follow-up of 15 months. Testing was successful in 81.7% of the patients. CGP detected targetable alterations in 35.3% of our BTC patients (most commonly ARID1A/ERBB2/IDH1/PIK3CA/BRAF-mutations and FGFR2-fusions). Recommendations for molecularly guided therapy were given in 46.4%. Of those, treatment implementation of targeted therapy followed in 19.4%. In patients receiving the recommended treatment, response rate was 57% and median overall survival was 19 months (vs 8 months in the untreated cohort). The progression-free survival ratio of 1.45 suggest a clinical benefit of molecularly guided treatment. CONCLUSIONS: In line with previous work, our series demonstrates feasibility and clinical utility of comprehensive genomic profiling in BTC patients. With the growing number of targeted agents with clinical activity in BTC, CGP should become standard of care in the management of this group of patients.

The effect of black seed (Nigella sativa) extract on lipid metabolism in HepG2 cells.

Black seed extract stimulates apolipoprotein A-I (apo A-I) gene expression in hepatocytes and intestinal cells in part by elevating peroxisome proliferator-activated receptor α (PPARα) and retinoid X receptor α (RXRα) levels. To explore potential ramifications of these observations, we examined the effects of black seed extract on hepatocyte lipid content and expression of key transcriptional regulators of fatty acid ß-oxidation and lipogenesis in HepG2 cells. PPARα, peroxisome proliferator-activated receptor γ (PPARγ), RXRα, thyroid hormone receptor ß (TRß), sterol-responsive element binding protein 1 (SREBP1), and sterol-responsive element binding protein 2 (SREBP2) levels were measured in black seed extract treated liver-derived HepG2 cells. Black seed extract treatment increased PPARα and RXRα expression and decreased intracellular neutral lipid content. Black seed extract treatment increased TRß expression and activity, and PPARα activity. In contrast, PPARγ, SREBP1 and SREBP2 levels were decreased in black seed extract treated cells. Black seed extract treatment also increased acyl-CoA synthetase long chain family member 5 (ACSL5), peroxisomal acyl-CoA oxidase 1 (ACOX1), and carnitine palmitoyl transferase 1A (CPT-1A) expression, three PPARα-dependent rate-limiting genes that facilitate fatty acid oxidation, similar to fenofibrate. PPARα knockdown reversed the effects of fenofibrate and blackseed on ACSL5, ACOX1, and CPT-1A expression. In conclusion, black seed extract-mediated lipid lowering in HepG2 cells is associated with increased expression of fatty acid oxidation enzymes and PPARα and reduced lipogenic signaling. Thus black seed extract may be potentially beneficial in metabolic diseases such as diabetes, cardiovascular disease, and metabolic syndrome.

Biodiversi-TEA-A quick and easy handling method for arthropod trap material in ethanol.

A quick and easy handling method for ethanol-preserved arthropods is presented, based on tea filter bags and holders. The method is especially suitable for short term storage of specimens resulting from Malaise traps, yellow pan traps and pitfall traps and can be used directly in the field, for subsequent transport and processing of specimens in the laboratory.

Prolonged time to treatment initiation in advanced pancreatic cancer patients has no major effect on treatment outcome: a retrospective cohort study controlled for lead time bias and waiting time paradox.

PURPOSE: A prolonged time to treatment initiation (TTI) correlates with an adverse prognosis in different cancer types including resectable pancreatic cancer (PC). Only limited evidence on the correlation between TTI and prognosis in advanced PC exists. METHODS: Consecutive PC patients (n = 368) who were diagnosed or treated at our high-volume comprehensive cancer center were included in a prospectively maintained database. We retrospectively analyzed time from first imaging showing advanced PC to initiation of palliative first-line chemotherapy. Lead time bias and waiting time paradox were addressed by landmark analysis and correlation of tumor burden with TTI. RESULTS: Two hundred and ninety-seven patients met the pre-specified in- and exclusion criteria of our study. Median TTI was 29 days (range: 1-124 days). Most common reasons for prolonged TTI (> 21 days) were referral from an external treatment center (39%) and a second biopsy (31%). A TTI above the median-, 75th or 90th percentile (43 or 60 days, respectively) had no impact on overall survival. Furthermore, no correlation between levels of carbohydrate antigen 19-9 (CA 19-9) at time of treatment initiation and TTI was observed. CONCLUSION: While a timely work-up of advanced PC patients remains important, delays in treatment initiation due to repeated biopsies, inclusion in a clinical study or transfer to a specialized cancer center appear to be justified in light of the absence of a strong adverse effect of prolonged TTI on prognosis in advanced PC patients.

Incidence, outcome and risk stratification tools for venous thromboembolism in advanced pancreatic cancer - A retrospective cohort study.

INTRODUCTION: Venous thromboembolism (VTE) is frequent in advanced pancreatic cancer (APC). Recent studies demonstrated that the Khorana score - an established risk stratification tool for VTE in cancer - performs poorly in identifying pancreatic cancer patients at high risk for VTE. MATERIALS AND METHODS: We performed a retrospective cohort study in order to define incidence, treatment and outcome of VTE as well as the performance of VTE risk stratification tools (Khorana score, CONKO score and aPTT ratio) in a "real life" clinical cohort of APC patients undergoing palliative chemotherapy. RESULTS AND CONCLUSIONS: One hundred and seventy-two eligible APC patients from our comprehensive cancer center were identified. VTE after start of palliative chemotherapy was diagnosed in 71 patients (41.3%). Most VTE events were asymptomatic (n=50, 29.1%) with only 21 symptomatic events (12.2%). On multivariate analysis - including age, performance status and carbohydrate antigen 19-9 (CA 19-9) - symptomatic VTE was an independent risk factor for death (hazard ratio [HR]: 2.22, 95% CI: 1.05-2.60, p<0.05). Khorana score, CONKO score and aPTT ratio alone were not able to predict the risk for symptomatic VTE. High risk patients could only be identified by using a combination of either Khorana or CONKO score with aPTT ratio (30% vs. 10% symptomatic VTE events in high vs. low risk patients, p<0.05). The combination of Khorana or CONKO score with aPTT thus may represent a novel risk stratification tool for symptomatic VTE in APC and should further be validated within prospective clinical trials.

Phase I/II Study of Refametinib (BAY 86-9766) in Combination with Gemcitabine in Advanced Pancreatic cancer.

BACKGROUND: Activating KRAS mutations are reported in up to 90% of pancreatic cancers. Refametinib potently inhibits MEK1/2, part of the MAPK signaling pathway. This phase I/II study evaluated the safety and efficacy of refametinib plus gemcitabine in patients with advanced pancreatic cancer. METHODS: Phase I comprised dose escalation, followed by phase II expansion. Refametinib and gemcitabine plasma levels were analyzed for pharmacokinetics. KRAS mutational status was determined from circulating tumor DNA. RESULTS: Ninety patients overall received treatment. The maximum tolerated dose was refametinib 50 mg twice daily plus standard gemcitabine (1000 mg/m2 weekly). The combination was well tolerated, with no pharmacokinetic interaction. Treatment-emergent toxicities included thrombocytopenia, fatigue, anemia, and edema. The objective response rate was 23% and the disease control rate was 73%. Overall response rate, disease control rate, progression-free survival, and overall survival were higher in patients without detectable KRAS mutations (48% vs. 28%, 81% vs. 69%, 8.8 vs. 5.3 months, and 18.2 vs. 6.6 months, respectively). CONCLUSION: Refametinib plus gemcitabine was well tolerated, with a promising objective response rate, and had an acceptable safety profile and no pharmacokinetic interaction. There was a trend towards improved outcomes in patients without detectable KRAS mutations that deserves future investigation.

Acinar cell carcinoma of the pancreas: a rare disease with different diagnostic and therapeutic implications than ductal adenocarcinoma.

PURPOSE: Acinar cell carcinoma (ACC) of the pancreas is a very rare cancer, constituting 1 % of all malignant non-endocrine pancreatic tumors. Only very limited data exist to guide treatment in patients with advanced ACC. METHODS: Between 2000 and 2015, 15 patients with ACC were diagnosed and/or treated at our high-volume comprehensive cancer center. Medical records and correlating serum levels of the potential serum tumor markers CA 19-9, CEA and lipase were analyzed retrospectively. RESULTS: A substantial antitumor activity was observed for treatment regimens containing 5-FU and oxaliplatin with partial responses or prolonged disease stabilizations (>12 months) observed in 6 out of 7 patients (86 %). Activity was also observed for single-agent 5-FU and its oral prodrugs. Serum lipase levels were elevated in 7 of 12 patients with advanced disease (58 %), whereas CEA and CA 19-9 seemed to be of minor importance for ACC (elevated pre-treatment levels in 4/12 and 3/12 cases, respectively). In selected patients, repeated serum lipase measurements were available and accurately predicted response to chemotherapy and relapse after surgery. CONCLUSIONS: 5-FU- and oxaliplatin-containing regimens are active in advanced ACC. Lipase kinetics may be a useful novel tool to monitor the course of disease as well as treatment effects in ACC.

Isolated pulmonary metastases define a favorable subgroup in metastatic pancreatic cancer.

PURPOSE: Liver metastasis represents the first site of dissemination in >80% of metastatic pancreatic cancer (PC) patients. Pulmonary metastasis as first site of dissemination in PC is a rare event and might define a biologically distinct subgroup in metastatic PC. METHODS: Consecutive PC patients who were diagnosed or treated with isolated pulmonary metastases at our high-volume comprehensive cancer center were included in a prospectively maintained database between 2002 and 2015. Medical records and correlating computed tomography findings (CT) were retrospectively analyzed. RESULTS: A total of 40 PC patients with isolated pulmonary metastases were identified. Pulmonary metastases represented disease recurrence after initial resection of PC in 22 patients and disease progression of locally advanced pancreatic cancer in 5 patients. 14 out of 27 PC patients (56%) had received chemoradiotherapy for localized disease prior to pulmonary metastasis. Data on 1st-line treatment for pulmonary metastases was available for 38 patients: most patients (71%) received a gemcitabine-based chemotherapy regimen, 5 patients (13%) received best supportive care. After a median follow-up of 37.3 months, median survival after diagnosis of pulmonary metastasis was estimated with 25.5 months (95% CI 19.1-31.8); a significantly improved survival after diagnosis of pulmonary metastasis was observed for patients with less than 10 lung metastases (31.3 vs 18.7 months, p = 0.003) and for an unilateral localization of lung involvement (31.3 vs 21.8 months, p = 0.03). CONCLUSIONS: Our results suggest a favorable outcome of PC patients with isolated pulmonary metastases. Further research is warranted to elucidate the specific molecular characteristics of this rare subgroup.

The glutathione mimic ebselen inhibits oxidative stress but not endoplasmic reticulum stress in endothelial cells.

AIMS: Reactive oxygen species are associated with cardiovascular disease, diabetes, and atherosclerosis, yet the use of antioxidants in clinical trials has been ineffective at improving outcomes. In endothelial cells, high-dextrose-induced oxidative stress and endoplasmic reticulum stress promote endothelial dysfunction leading to the recruitment and activation of peripheral blood lymphocytes and the breakdown of barrier function. Ebselen, a glutathione peroxidase 1 (GPX1) mimic, has been shown to improve ß-cell function in diabetes and prevent atherosclerosis. MAIN METHODS: To determine if ebselen inhibits both oxidative stress and endoplasmic reticulum (ER) stress in endothelial cells, we examined its effects in human umbilical vein endothelial cells (HUVEC) and human coronary artery endothelial cells (HCAEC) with and without high-dextrose. Oxidative stress and ER stress were measured by 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence and ER stress alkaline phosphatase assays, respectively. GPX1 over-expression and knockdown were performed by transfecting cells with a GPX1 expression construct or a GPX1-specific siRNA, respectively. KEY FINDINGS: Ebselen inhibited dextrose-induced oxidative stress but not ER stress in both HUVEC and HCAEC. Ebselen also had no effect on tunicamycin-induced ER stress in HCAEC. Furthermore, augmentation of GPX1 activity directly by sodium selenite supplementation or transfection of a GPX1 expression plasmid decreased dextrose-induced oxidative stress but not ER stress, while GPX1 knockout enhanced oxidative stress but had no effect on ER stress. SIGNIFICANCE: These results suggest that ebselen targets only oxidative stress but not ER stress.

Induction of apolipoprotein A-I gene expression by black seed (Nigella sativa) extracts.

CONTEXT: Black seed [Nigella sativa L. (Ranunculaceae)] has been shown in animal models to lower serum cholesterol levels. OBJECTIVES: In order to determine if extracts from black seed have any effects on high-density lipoprotein (HDL), we characterized the effects of black seed extract on apolipoprotein A-I (apo A-I) gene expression, the primary protein component of HDL. MATERIALS AND METHODS: Hepatocytes (HepG2) and intestinal cells (Caco-2) were treated with black seed extracts, and Apo A-I, peroxisome proliferator-activated receptor α (PPARα), and retinoid-x-receptor α (RXRα) were measured by Western blot analysis. Apo A-I mRNA levels were measured by quantitative real-time polymerase chain reaction and apo A-I gene transcription was measured by transient transfection of apo A-I reporter plasmids. RESULTS: Extracts from black seeds significantly increased hepatic and intestinal apo A-I secretion, as well as apo A-I mRNA and gene promoter activity. This effect required a PPARα binding site in the apo A-I gene promoter. Treatment of the extract with either heat or trypsin had no effect on its ability to induce apo A-I secretion. Treatment with black seed extract induced PPARα expression 9-fold and RXRα expression 2.5-fold. Furthermore, the addition of PPARα siRNA but not a control siRNA prevented some but not all the positive effects of black seed on apo A-I secretion. DISCUSSION: Black seed extract is a potent inducer of apo A-I gene expression, presumably by enhancing PPARα/RXRα expression. CONCLUSIONS: We conclude that black seed may have beneficial effects in treating dyslipidemia and coronary heart disease.

Complete pathological response to neoadjuvant pemetrexed/cisplatin in combination with regional hyperthermia in a patient with sarcomatoid peritoneal mesothelioma.

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare disease. Although most patients eligible for surgery undergo cytoreductive surgery in combination with hyperthermic intraperitoneal chemotherapy, the role of perioperative systemic chemotherapy still remains undefined. Here we report the case of a 52-year-old female patient with advanced sarcomatoid DMPM. After five cycles of systemic pemetrexed and cisplatin, along with two cycles of regional hyperthermia, tumor resection with histomorphological examination showed a complete pathological response. We therefore conclude that there is a subgroup of DMPM patients that might benefit from systemic neoadjuvant chemotherapy with pemetrexed and cisplatin.

The effect of nutritional supplements on serum high-density lipoprotein cholesterol and apolipoprotein A-I.

One of the factors contributing to the increased risk of developing premature atherosclerosis is low plasma concentrations of high-density lipoprotein (HDL) cholesterol. Multiple potential mechanisms account for the cardioprotective effects of HDL and its main protein apolipoprotein A-I (apo A-I). Diet has an important role in modulating HDL cholesterol level. The widespread use of nutritional supplements may also alter the biology of HDL. In this review, we discuss the effect of select nutritional supplements on serum HDL cholesterol and apo A-I levels. Some nutritional supplements, such as phytosterols, soy proteins, and black seed extracts, may increase HDL cholesterol levels, while others such as cholic acid and high doses of commonly used antioxidant vitamins may downregulate HDL cholesterol levels and reduce its cardioprotection. Multiple mechanisms are involved in the regulation of HDL levels, so changes in production and clearance of HDL may have different clinical implications. The clinical relevance of the changes in HDL and apo A-I caused by nutrient supplementation needs to be tested in controlled clinical trials.

The effect of black seed (Nigella sativa) extract on FOXO3 expression in HepG2 cells.

Black seed extracts are known to alter cellular metabolism through multiple signaling pathways. Since Forkhead box transcription factor 3 (FOXO3) has a significant role in regulating cellular metabolism, the effect of lipid extracts of black seed (Sativa nigella) on FOXO3 levels and AKT and 5-AMP activated protein kinase α (AMPKα) signaling was measured in HepG2 hepatoma cells. FOXO3 levels, phosphorylation, and nuclear exclusion were measured by Western blot, as were AKT and AMPK expression and activity using phosphorylation-specific antibodies. Apolipoprotein A-I expression, a black seed-responsive gene, was measured by Western blot. Treatment with black seed extract increased FOXO3 phosphorylation and decreased its expression. In contrast to control cells where FOXO3 was located primarily in the nucleus, in black seed-treated HepG2 cells, FOXO3 was localized primarily to the cytoplasm. These changes in FOXO3 phosphorylation, expression, and localization were accompanied by increased AKT activity. Black seed also decreased AMPKα activity but increased AMPKα expression. Lipid extracts from black seeds inhibit FOXO3 activity and thereby modulate the expression of FOXO3-dependent genes.

Clinical relevance and utility of cetuximab-related changes in magnesium and calcium serum levels.

Hypomagnesemia and hypocalcemia are common adverse events during cetuximab treatment. The influence of the chemotherapeutic combination on serum levels is unknown and the predictive value is currently under discussion. This analysis investigated 79 patients who had received cetuximab for at least 6 weeks in the day clinic of the Comprehensive Cancer Center, University of Munich. Calcium and magnesium serum levels were analyzed weekly; tumor response and adverse events were followed. Thirty-eight patients had metastatic colorectal cancer (mCRC) and the predictive value of hypomagnesemia was tested in these patients. During therapy, calcium serum levels decreased to about 97% of the baseline levels and were maintained for the duration of treatment. Magnesium levels showed a significant time-dependent decrease. Serum levels of magnesium were lower when cetuximab was combined with a platinum derivative. After a treatment duration of 12 weeks, magnesium levels decreased to 70% in platinum-treated patients, whereas they decreased to only 90% of baseline in patients who did not receive platinum therapy. In patients treated for mCRC, a decrease of serum magnesium below 95% of the baseline levels 14 days after initiating treatment separated patients significantly in terms of survival times. Magnesium levels decrease in a time-dependent manner during cetuximab therapy. As hypomagnesemia was more prominent in patients receiving platinum agents, magnesium measurements may be advised in these patients. In mCRC patients treated with cetuximab, day-14 magnesium serum levels correlated with treatment efficacy.

Prion infected meat-and-bone meal is still infectious after biodiesel production.

The epidemic of bovine spongiform encephalopathy (BSE) has led to a world-wide drop in the market for beef by-products, such as Meat-and-Bone Meal (MBM), a fat-containing but mainly proteinaceaous product traditionally used as an animal feed supplement. While normal rendering is insufficient, the production of biodiesel from MBM has been suggested to destroy infectivity from transmissible spongiform encephalopathies (TSEs). In addition to producing fuel, this method simultaneously generates a nutritious solid residue. In our study we produced biodiesel from MBM under defined conditions using a modified form of alkaline methanolysis. We evaluated the presence of prion in the three resulting phases of the biodiesel reaction (Biodiesel, Glycerol and Solid Residue) in vitro and in vivo. Analysis of the reaction products from 263K scrapie infected MBM led to no detectable immunoreactivity by Western Blot. Importantly, and in contrast to the biochemical results the solid MBM residue from the reaction retained infectivity when tested in an animal bioassay. Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.

The effect of glucosamine on Serum HDL cholesterol and apolipoprotein AI levels in people with diabetes.

OBJECTIVE: Dietary and nutritional supplements are modulators of HDL cholesterol levels and production of apolipoprotein (apo) AI. Previously, in vitro treatment of hepatocyte cell lines with glucosamine increased apoAI production by stabilization of apoAI mRNA. The hypothesis is that the neutraceutical glucosamine, when given in conventional doses (1,500 mg/day) may increase apoAI and HDL cholesterol levels in subjects with diabetes and low HDL cholesterol. RESEARCH DESIGN AND METHODS: Twelve subjects (three men and nine women) with type 1 (n = 2) and type 2 (n = 10) diabetes, aged 55 +/- 12 years (mean +/- SD), who had low HDL cholesterol (1.03 +/- 0.20 mmol/l), were randomly assigned to a double-blind, placebo-controlled, cross-over trial of 500 mg glucosamine or placebo orally three times daily for 2 weeks, followed by a 4-week washout phase and a 2-week cross-over to the alternate therapy. RESULTS: Fasting serum glucose, fructosamine, and total cholesterol remained stable during the drug and placebo phases. Glucosamine had no significant effect after therapy on serum levels of HDL cholesterol (from baseline of 1.02 +/- 0.15 to 1.05 +/- 0.16 mmol/l compared with placebo from 1.04 +/- 0.21 to 1.06 +/- 0.16 mmol/l) nor in changes in apoAI levels (from baseline of 147 +/- 15 to 140 +/- 126 mg/dl with glucosamine and from 146 +/- 25 to 142 +/- 17 mg/dl with placebo). CONCLUSIONS: These observations suggest that glucosamine at commonly consumed doses does not have significant effects on glycemic control, lipid profile, or levels of apoAI in diabetic subjects after 2 weeks of supplementation.

A process model to estimate biodiesel production costs.

'Biodiesel' is the name given to a renewable diesel fuel that is produced from fats and oils. It consists of the simple alkyl esters of fatty acids, most typically the methyl esters. We have developed a computer model to estimate the capital and operating costs of a moderately-sized industrial biodiesel production facility. The major process operations in the plant were continuous-process vegetable oil transesterification, and ester and glycerol recovery. The model was designed using contemporary process simulation software, and current reagent, equipment and supply costs, following current production practices. Crude, degummed soybean oil was specified as the feedstock. Annual production capacity of the plant was set at 37,854,118 l (10 x 10(6)gal). Facility construction costs were calculated to be US dollar 11.3 million. The largest contributors to the equipment cost, accounting for nearly one third of expenditures, were storage tanks to contain a 25 day capacity of feedstock and product. At a value of US dollar 0.52/kg (dollar 0.236/lb) for feedstock soybean oil, a biodiesel production cost of US dollar 0.53/l (dollar 2.00/gal) was predicted. The single greatest contributor to this value was the cost of the oil feedstock, which accounted for 88% of total estimated production costs. An analysis of the dependence of production costs on the cost of the feedstock indicated a direct linear relationship between the two, with a change of US dollar 0.020/l (dollar 0.075/gal) in product cost per US dollar 0.022/kg (dollar 0.01/lb) change in oil cost. Process economics included the recovery of coproduct glycerol generated during biodiesel production, and its sale into the commercial glycerol market as an 80% w/w aqueous solution, which reduced production costs by approximately 6%. The production cost of biodiesel was found to vary inversely and linearly with variations in the market value of glycerol, increasing by US dollar 0.0022/l (dollar 0.0085/gal) for every US dollar 0.022/kg (dollar 0.01/lb) reduction in glycerol value. The model is flexible in that it can be modified to calculate the effects on capital and production costs of changes in feedstock cost, changes in the type of feedstock employed, changes in the value of the glycerol coproduct, and changes in process chemistry and technology.

Effect of chromium on apolipoprotein A-I expression in HepG2 cells.

OBJECTIVE: Chromium is a key micronutrient required for lipid and carbohydrate metabolism. Some but not all clinical trials have associated use of chromium supplements with improved insulin sensitivity and lipid profile including increased high-density lipoprotein cholesterol levels. METHODS: Because apolipoprotein A-I (apoA-I) is the principal protein of high-density lipoprotein, the molecular pathways underlying chromium-related changes in apoA-I expression were studied in a human hepatoma cell line (HepG2) transfected with full-length apoA-I promoter attached to the reporter chloramphenicol acetyl transferase gene. RESULTS: Exposure of these cells to different concentrations of chromium chloride (0, 0.5, 1.0, and 3.0 mM) resulted in a dose-dependent decrease in apoA-I promoter activity (chloramphenicol acetyl transferase activity expressed as a percentage of an internal control was 99.4 +/- 7.2% in control cells versus 87.6 +/- 5.0%, 73.4 +/- 2.3%, and 36.6 +/- 3.9%, respectively, P < 0.01). Chromium chloride at 10 mM concentration was toxic and caused death in a large number of cells. Treating HepG2 cells with other minerals known to have insulin-sensitizing effects such as magnesium (1 mM), zinc (0.2 mM), and vanadyl sulfate (0.1 mM) significantly reduced apoA-I promoter activity in the presence and absence of 100 microU/mL of insulin. Northern blot analyses showed that the apoA-I mRNA content of cells treated with 0.2 mM of chromium chloride relative to G3PDH mRNA was not significantly increased compared with controls (0.652 +/- 0.122 versus 0.745 +/- 0.143, the ratio of apoA-I to glyceraldehyde 3-phosphate dehydrogenase (G3PDH) mRNA in control and chromium-treated cells, respectively). Western blot analyses of proteins secreted in culture media indicated that neither chromium treatment of the HepG2 cells (858.0 +/- 151.4 arbitrary units) nor treatment with magnesium (1323.3 +/- 175.7) or vanadium (1102 +/- 78.7) significantly altered apoA-I concentrations compared with controls (1061.7 +/- 114.7). However treatment of HepG2 cells with 0.2 mM of zinc significantly reduced apoA-I concentrations (291.0 +/- 29.2 versus 1061.7 +/- 114.7; P < 0.001). CONCLUSIONS: Supraphysiologic concentrations of chromium and other minerals with known insulin-sensitizing activity may reduce apoA-I promoter activity in cultured cells. Whether similar changes may occur in vivo remains to be shown. However, these observations do not support the use of pharmacologic amounts of chromium supplementation to enhance the cardioprotective lipid profile.

The isolation and identification of a toxic impurity in XP315 drug substance.

In early safety assessment studies with the experimental anti-neoplastic drug XP315, a toxic reaction was observed in dogs immediately after intravenous (iv) infusion. The reaction was characterized by severe erythema around the ears, eyes, face and body; ocular hyperemia; head shaking; swelling around the eyes, face, paws, head, neck and legs; scratching; and reddened gums, which lasted several hours after dosing. By fractionating the drug substance using preparative HPLC and then infusing the residues into dogs by iv, this reaction was traced to an impurity in the drug substance. Following the preparative isolation of the toxic impurity, characterization was performed using a combination of NMR and mass spectral methods. The proposed impurity was found to be structurally related and nearly twice the molecular weight of XP315, resulting from a dimerization by ring fusion of two 3-aminonaphthalene fragments during the synthetic process. This paper details the steps taken to isolate the toxic impurity and characterize its structure using off-line methods.