Origin of Myofibroblasts in Lung Fibrosis

Purpose of Review

In this brief review, we will highlight important observational and experimental data in the literature that address the origin of scar-forming cells in lung fibrosis.

Recent Findings

Several cellular sources of activated scar-forming cells (myofibroblasts) have been postulated including alveolar epithelial cells; circulating fibrocytes; and lung stromal cell subpopulations including resident fibroblasts, pericytes, and resident mesenchymal stem cells. Recent advances in lineage-tracing models, however, fail to provide experimental evidence for epithelial and fibrocyte origins of lung myofibroblasts. Resident mesenchymal cells of the lung, which include various cell types including resident fibroblasts, pericytes, and resident mesenchymal stem cells, appear to be important sources of myofibroblasts in murine models of lung injury and fibrosis.

Summary

Lung myofibroblasts likely originate from multiple sources of lung-resident mesenchymal cells. Their relative contributions may vary depending on the type of injury. Although lineage-tracing experiments have failed to show significant contribution from epithelial cells or fibrocytes, they may play important functional roles in myofibroblast activation through paracrine signaling.

Inhibitory Actions of Berberine on Growth and Arylamine N-Acetyltransferase Activity in Strains of Helicobacter Pylori from Peptic Ulcer Patients

N-acetyltransferase(NAT)-catalyzed reactions can result in activation or detoxification of arylamine carcinogens. Studies were conducted to examine the dose effects of berberine on inhibition of growth versus arylamine NAT activities in strains of Helicobacter pylori collected from peptic ulcer patients. An inhibition-of-growth study on H. pylori demonstrated that berberine elicited a dose-dependent growth inhibition in the H. Pylori cultures. The results on the NAT activity was determined using acetyl coenzyme A recycling assay and high pressure liquid chromatography. Cyto-sols or suspensions of H. pylori with or without selected concentrations of berberine cotreatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicated that there was decreased NAT activity associated with increased levels of berberine in the H. pylori cytosols and suspensions. The apparent values of Km and Vmax also decreased after cotreatment of berberine in both examined systems. This report is the first finding of berberine inhibition of arylamine NAT activity in strains of H. pylori.

Imaging findings in mandibular primitive neuroectodermal tumour: a report of a rare case and review of the literature

Primitive neuroectodermal tumours (PNETs) are aggressive undifferentiated tumours that occur mainly in the central nervous system (CNS). Reviewing the literature, only six cases of primary PNET of the mandible have been reported. These rare tumours are usually overlooked in clinical practice. An 18-year-old woman who presented with dental caries and left cheek swelling was initially diagnosed with facial cellulitis, but the swelling persisted despite adequate intravenous antibiotic therapy. Subsequent ultrasound and MR examinations revealed a tumour originating from the left mandibular ramus. The ultrasonography-guided percutaneous core needle biopsy confirmed the diagnosis of peripheral PNET. The radiographic features of mandibular PNETs are similar to those of PNETs in other regions, except for haemorrhage, necrosis and calcification. In addition, this is the first reported case with sonographic and MR images of this rare tumour, and the first case that was diagnosed based on the ultrasonography-guided percutaneous core needle biopsy. Using these image characteristics, mandibular PNETs can be diagnosed more accurately.

Impact of long-term treatment with neurotoxic dideoxynucleoside antiretrovirals: implications for clinical care in resource-limited settings

OBJECTIVES

A minority of HIV-infected patients taking an antiretroviral (ARV) regimen containing dideoxynucleosides (d-drugs) such as stavudine (d4T) and didanosine (DDI) experiences dose-limiting neuropathic pain and paraesthesias, usually within weeks of starting these drugs. Because d-drugs are among the few affordable options available in developing countries, continuing d-drug therapy would be a desirable strategy for many HIV-infected individuals. Therefore, we evaluated the safety of continuing d-drug therapy.

METHODS

In a US cohort, we compared the rates of worsening neuropathic symptoms and signs in HIV-infected individuals on stable ARV regimens that did (n=252) or did not (n=250) include d-drugs. Rates of worsening were compared using proportional hazards model and the log-rank test.

RESULTS

The risk ratios (RR) were not significantly larger for worsening neuropathy signs [0.94; 95% confidence interval (CI) 0.84-1.07] or symptoms (0.99; 95% CI 0.88-1.14) in patients taking d-drugs continuously compared to those not taking d-drugs.

CONCLUSIONS

Continued d-drug exposure among patients tolerating an initial trial did not increase the risk of worsening neuropathy compared to non-d-drug-containing regimens. If applicable in developing countries, these findings suggest that in most patients d-drugs can be continued safely in the long term without increasing the risk of worsening neuropathy.

Determination of carotenoids and their esters in fruits of Lycium barbarum Linnaeus by HPLC-DAD-APCI-MS

The fruit of Lycium barbarum Linnaeus, a traditional Chinese herb containing functional components such as carotenoids, flavonoids and polysaccharides, has been widely used in the health food industry because of its possible role in the prevention of chronic disease like age-related macular degeneration. The objectives of this study were to develop a high performance liquid chromatography-photo diode array detection-mass spectrometry (HPLC-DAD-MS) method with atmospheric pressure chemical ionization (APCI) mode for qualitative and quantitative analyses of carotenoids in fruits of L. barbarum. Dried samples of L. barbarum were subjected to extraction without saponification or extraction followed by saponification. A C30 column with a gradient mobile phase of methylene chloride (100%) and methanol-acetonitrile-water (81:14:5, v/v/v) was used to separate carotenoids, with a total of 11 free carotenoids and 7 carotenoid esters being resolved from unsaponified and saponified L. barbarum extracts within 51 and 41 min, respectively. The fatty acid composition of carotenoid esters was confirmed by gas chromatography. Zeaxanthin dipalmitate (1143.7 microg/g) was present in the largest amount, followed by beta-cryptoxanthin monopalmitate and its two isomers (32.9-68.5 microg/g), zeaxanthin monopalmitate and its two isomers (11.3-62.8 microg/g), all-trans-beta-carotene (23.7 microg/g) and all-trans-zeaxanthin (1.4 microg/g).

Anti-inflammatory effects of isoflavone powder produced from soybean cake

Soybean cake, a byproduct obtained during the processing of soybean oil, has been shown to be a rich source of isoflavones. The objectives of this study were to use soybean cake as raw material for processing into powder and to evaluate the anti-inflammatory activity. Eleven treatments, including powders of malonylglucoside, glucoside, acetylglucoside, aglycone, ISO-1, and ISO-2, as well as genistein standard, gamma-PGA, control, normal, and PDTC, were used for evaluation. A total of 77 mice were each provided daily with tube feeding for 4 weeks at a dose of 0.3 mL of aqueous solution from each treatment, and inflammation was induced with intraperitoneal injection of 1 mg/kg of body weight lipopolysaccharide (LPS). Results showed that all of the isoflavone powders and genistein standard were effective in inhibiting LPS-induced inflammation, lowering leukocyte number in mice blood and reducing production of IL-1beta, IL-6, NO, and PGE2 in both peritoneal exudate cell supernatant and peritoneal exudate fluid. All of the isoflavone treatments failed to retard T cell proliferation; however, both ISO-1 and ISO-2 could inhibit B cell proliferation. The difference in anti-inflammatory activity was minor between any of the isoflavone treatments.

Tamoxifen inhibits arylamine N-acetyltransferase activity and DNA-2-aminofluorene adduct in human leukemia HL-60 cells

Genetic regulation of acetyl coenzyme A-dependent N-acetyltransferase (NAT)and O-acetyltransferase (OAT) activities may play an important role in the metabolic activation of arylamine chemicals and carcinogens. N-acetylation is thought to be the first step in arylamine metabolism. The enzyme responsible for N-acetylation is called NAT. In this study, synthetic non-steroidal antiestrogen tamoxifen was selected for determining the inhibition of arylamine NAT activity, gene expression (NAT mRNA) and DNA-2-aminofluorene adduct formation in human leukemia HL-60 cell line. The results demonstrated that tamoxifen did not affect the level of NAT mRNA in HL-60 cells. But the results also showed that NAT activity and 2-Aminofluorene-DNA adduct formation in HL-60 cells were inhibited and decreased by tamoxifen in a dose-dependent manner when the doses of tamoxifen up to 100 micro M. We also examined the standard steady-state kinetic analysis, and the data showed that tamoxifen may be an uncompetitive inhibitor to NAT activity in cytosols based on the decrease apparent values of Km and Vmax. This report is the first finding that tamoxifen inhibited human leukemia HL-60 cells NAT activity and DNA-2-aminofluorene on adduct formation.

CD8+ T cells, NK cells and IFN-gamma are important for control of tumor with downregulated MHC class I expression by DNA vaccination

One of the major hurdles facing cancer immunotherapy is that cancers may downregulate expression of MHC class I molecules. The development of a suitable tumor model with downregulated MHC class I expression is critical for designing vaccines and immunotherapeutic strategies to control such tumors. We developed an E7-expressing murine tumor model with downregulated MHC class I expression, TC-1 P3 (A15). Using this model, we tested DNA and vaccinia vaccines for their ability to control tumors with downregulated MHC class I expression. We found that vaccination with DNA encoding E7 linked to Mycobacterial heat shock protein 70 (HSP70) generated a significant antitumor effect against TC-1 P3 (A15), while vaccination with E7/HSP70 vaccinia did not generate an appreciable antitumor effect. Lymphocyte depletion experiments revealed that both CD8+ T cells and NK cells were essential for the antitumor effect generated by E7/HSP70 DNA against TC-1 P3 (A15). Furthermore, tumor protection experiments using IFN-gamma knockout mice revealed that IFN-gamma was essential for the antitumor effect generated by E7/HSP70 DNA against TC-1 P3 (A15). Our results demonstrate that vaccination with E7/HSP70 DNA results in a significant antitumor effect against a neoplasm with downregulated MHC class I expression and the importance of CD8+ T cells, NK cells, and IFN-gamma in generating this antitumor effect.

Curcumin inhibited the arylamines N-acetyltransferase activity, gene expression and DNA adduct formation in human lung cancer cells (A549)

It is well known that N-acetyltransferase (NAT) plays an important role in the arylamine metabolism. We analysed the response of A549 human lung cancer cells for N-acetylation of 2-aminofluorene (AF) to curcumin. After curcumin treatment, the NAT activity was examined by HPLC, AF-DNA adduct formation was examined by HPLC, and NAT gene expression by polymerase chain reaction were detected. The NAT activity in the human A549 cells and cytosols was suppressed by curcumin in a dose-dependent manner. The results also demonstrated that gene expression (NAT1 mRNA) in human lung A549 tumor cells was inhibited and decreased by curcumin. After the incubation of human lung A549 tumor cells with AF with or without curcumin co-treatment, the cells were recovered and DNA was prepared and hydrolyzed to nucleotides. The adducted nucleotides were extracted into butanol and analyzation of AF-DNA adducts was done by HPLC. The results also demonstrated that curcumin decreases AF-DNA adduct formation in the human lung A549 tumor cells.

Effects of garlic components diallyl sulfide and diallyl disulfide on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adducts in human promyelocytic leukemia cells

Two components of garlic, diallyl sulfide (DAS) and diallyl disulfide (DADS), inhibited arylamine N-acetyltransferase (NAT) activity and 2-aminofluorene-DNA adduct in human promyelocytic leukemia cells (HL-60). The NAT activity was measured by high performance liquid chromatography assaying for amounts of N-acetyl-2-aminofluorene (2-AAF) and remaining 2-aminofluorene (2-AF). Cellular cytosols and intact cell suspensions were assayed. The inhibition of NAT activity and 2-AF-DNA adduct formation in human leukemia cells by DAS and DADS were dose-dependent and were directly proportional. The data also indicated that DAS and DADS decrease the apparent values of Km and Vmax from human leukemia cells in both assays. This is the first report of garlic components affecting human leukemia cell NAT activity and 2-AF-DNA adduct formation.

Berberine inhibited arylamine N-acetyltransferase activity and gene expression and DNA adduct formation in human malignant astrocytoma (G9T/VGH) and brain glioblastoma multiforms (GBM 8401) cells

Studies have demonstrated that berberine exhibits the antineoplastic action in rat model. Rat glial tumor cells also have been shown to have N-acetyltransferase activity. In this study, we reported the effects of berberine on arylamine N-acetyltransferase (NAT) activity, gene expression, and DNA adduct formation in human brain tumor cell lines (G95/VGH and GBM 8401). The activity of NAT (N-acetylation of substrate) was measured and determined by high-performance liquid chromatography (HPLC) assaying for the amounts of acetylated 2-aminofluorene (AF) and nonacetylated AF. Human brain tumor cells (G9T/VGH and GBM 8401) were used for examining NAT activity and gene expression and AF-DNA adduct formation. NAT gene expression was determined by polymerase chain reaction (PCR) for the levels of mRNA NAT in both examined cells lines. The amounts of AF-DNA adducts were also determined and quantities by HPLC. The results demonstrated that NAT activity, levels of mRNA NAT1 and AF-DNA adduct formation in both examined cell were inhibited and decreased by berberine in a dose-dependent manner. The apparent values of Km and Vmax from NAT of both examined cells were also determined with or without berberine cotreatment. The data also indicated that berberine decreased the apparent values of Km and Vmax. These effects also indicate that berberine is a uncompetitive inhibitor.

The effect of paclitaxel on 2-aminofluorene-DNA adducts formation and arylamine N-acetyltransferase activity and gene expression in human lung tumor cells (A549)

In this study, paclitaxel was used to determine inhibition of arylamine N-acetyltransferase (NAT) activity, gene expression and 2-aminofluorene-DNA adduct formation in a human lung tumor cell line (A549). The activity of NAT was measured by HPLC assaying for the amounts of N-acetyl-2-aminofluorene (2-AAF) and remaining 2-aminofluorene (2-AF). Human lung tumor cell cytosols and intact cells were used for examining NAT activity and carcinogen-DNA adduct formation. The results demonstrated that NAT activity, gene expression (NAT1 mRNA) and 2-AF-DNA adduct formation in human lung tumor cells were inhibited and decreased by paclitaxel in a dose-dependent manner. The effects of paclitaxel on the values of the apparent Km and Vmax of NAT from human lung tumor cells were also determined in both examined systems. The result also indicated that paclitaxel decreased the apparent values of Km and Vmax from human lung tumor cells in both cytosol and intact cells. Thus, paclitaxel is an uncompetitive inhibitor to NAT enzyme.

Ellagic [correction of ellagica] acid inhibits arylamine N-acetyltransferase activity and DNA adduct formation in human bladder tumor cell lines (T24 and TSGH 8301)

The fact that vitamin C (ascorbic acid) exhibits a protective effect in certain types of cancer is well documented. Our previous studies demonstrated that human bladder tumor cell line (T24) has N-acetyltransferase (NAT) activity in cytosols and intact cells. The present studies examined the inhibition of arylamine NAT activity and carcinogen (2-aminofluorene)-DNA adduct formation by ellagic acid (EA) in human bladder tumor cell lines (T24 and TSGH 8301). Two assay systems were performed, one with cellular cytosols (9,000 g supernatant), the other with intact bladder tumor cell suspensions. NAT activity and 2-aminofluorene-DNA adduct formation in T24 and TSGH 8301 cells was inhibited by EA in a dose-dependent manner in both systems, i.e.. the greater the concentration of EA in the reaction the greater the inhibition of NAT activity (dose- and time-course dependent effects). The data also indicated that EA decreased the apparent Km and Vmax of NAT enzymes from T24 and TSGH 8301 cells in cytosols. NAT activity and 2-aminofluorene-DNA adducts in T24 is higher than in TSGH 8301. This report is the first to demonstrate that EA affects human bladder tumor cell NAT activity.

Nonfunctioning malignant pheochromocytoma associated with dermatomyositis: case report and literature review

A 42-year-old man with dermatomyositis presented with right-upper-quadrant dull pain and normal blood pressure for 10 days. Abdominal ultrasonography, abdominal computed tomography, and angiography revealed a retroperitoneal tumor with direct invasion to the liver and the diaphragm. The diagnosis of nonfunctioning malignant pheochromocytoma was made on the basis of clinical evidence. The tumor was removed en bloc with part of the diaphragm, the right lobe of the liver, the right adrenal gland, and the right kidney. Pathologic examination with immunohistochemical staining revealed a malignant pheochromocytoma growing exophytically from the right adrenal gland and invading the right lobe of the liver and the diaphragm. The postoperative course has been uneventful and no recurrence has been noted over a 6-month follow-up period.

Kinetics of acetyl coenzyme A: arylamine N-acetyltransferase from rapid and slow acetylator human benign prostatic hyperplasia tissues

N-acetyltransferase (NAT) activity was determined in 40 human benign prostatic hyperplasia tissues using 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) as substrates. These were then assayed by high performance liquid chromatography for determining the amounts of acetylated AF and PABA and non-acetylated AF and PABA. The activities (mean +/- SD) of AF-NAT from human benign prostatic hyperplasia tissues were divided into rapid (2.06 +/- 0.08 nmol/min per milligram protein), intermediate (1.25 +/- 0.26 nmol/min per milligram protein), and slow (0.58 +/- 0.30 nmol/min per milligram protein) acetylator groups. The activities (mean +/- SD) of PABA-NAT from human benign prostatic hyperplasia tissues were also divided into rapid (2.00 +/- 0.00 nmol/min per milligram protein), intermediate (1.25 +/- 0.18 nmol/min per milligram protein), and slow (0.48 +/- 0.29 nmol/min per milligram protein) acetylator groups. Kinetic constants for arylamine NAT activities were determined for each of these acetylator groups. Apparent differences in Km and Vmax for AF were found. Therefore, there seems to be a polymorphism in NAT activity with two rapid, five intermediate, and 33 slow acetylators among the 40 samples assayed. This is the first demonstration of acetyl CoA-arylamine NAT activity in human benign prostatic hyperplasia tissues.

Vitamin C inhibited DNA adduct formation and arylamine N-acetyltransferase activity and gene expression in rat glial tumor cells

Studies have been demonstrated that vitamin C (ascorbic acid) exhibit the protective role of vin in certain types of cancer. Rat glial tumor cells also have been shown have N-acetyltransferase activity. In this study, we reported the effects of vitamin C on arylamine N-acetyltransferase (NAT) activity and DNA adduct formation in rat glial tumor cell line (C6 glioma). The activity of NAT was measured by high performance liquid chromatography assaying for the amounts of acetylated 2-aminofluorene and p-aminobenzoic acid and nonacetylated 2-aminofluorene and p-amonibenzoic acid. Rat C6 glioma cells were used for examining NAT activity and gene expression and 2-aminofluorene-DNA adduct formation. The results demonstrated that NAT activity and 2-aminofluorene-DNA adduct formation in C6 glioma cells were inhibited and decreased by vitamin C in a dose-dependent manner. But vitamin C did not affect NAT gene expression in examined cells. The apparent kinetic parameters (apparent values of Km and Vmax) from C6 glioma cells were also determined with or without vitamin C cotreatment. The data also indicated that vitamin C decreased the apparent values of Km and Vmax from C6 glioma cells.

Tumor-specific immunity and antiangiogenesis generated by a DNA vaccine encoding calreticulin linked to a tumor antigen

Antigen-specific cancer immunotherapy and antiangiogenesis have emerged as two attractive strategies for cancer treatment. An innovative approach that combines both mechanisms will likely generate the most potent antitumor effect. We tested this approach using calreticulin (CRT), which has demonstrated the ability to enhance MHC class I presentation and exhibit an antiangiogenic effect. We explored the linkage of CRT to a model tumor antigen, human papilloma virus type-16 (HPV-16) E7, for the development of a DNA vaccine. We found that C57BL/6 mice vaccinated intradermally with CRT/E7 DNA exhibited a dramatic increase in E7-specific CD8(+) T cell precursors and an impressive antitumor effect against E7-expressing tumors compared with mice vaccinated with wild-type E7 DNA or CRT DNA. Vaccination of CD4/CD8 double-depleted C57BL/6 mice and immunocompromised (BALB/c nu/nu) mice with CRT/E7 DNA or CRT DNA generated significant reduction of lung tumor nodules compared with wild-type E7 DNA, suggesting that antiangiogenesis may have contributed to the antitumor effect. Examination of microvessel density in lung tumor nodules and an in vivo angiogenesis assay further confirmed the antiangiogenic effect generated by CRT/E7 and CRT. Thus, cancer therapy using CRT linked to a tumor antigen holds promise for treating tumors by combining antigen-specific immunotherapy and antiangiogenesis.

Tumor-specific immunity and antiangiogenesis generated by a DNA vaccine encoding calreticulin linked to a tumor antigen

Antigen-specific cancer immunotherapy and antiangiogenesis have emerged as two attractive strategies for cancer treatment. An innovative approach that combines both mechanisms will likely generate the most potent antitumor effect. We tested this approach using calreticulin (CRT), which has demonstrated the ability to enhance MHC class I presentation and exhibit an antiangiogenic effect. We explored the linkage of CRT to a model tumor antigen, human papilloma virus type-16 (HPV-16) E7, for the development of a DNA vaccine. We found that C57BL/6 mice vaccinated intradermally with CRT/E7 DNA exhibited a dramatic increase in E7-specific CD8(+) T cell precursors and an impressive antitumor effect against E7-expressing tumors compared with mice vaccinated with wild-type E7 DNA or CRT DNA. Vaccination of CD4/CD8 double-depleted C57BL/6 mice and immunocompromised (BALB/c nu/nu) mice with CRT/E7 DNA or CRT DNA generated significant reduction of lung tumor nodules compared with wild-type E7 DNA, suggesting that antiangiogenesis may have contributed to the antitumor effect. Examination of microvessel density in lung tumor nodules and an in vivo angiogenesis assay further confirmed the antiangiogenic effect generated by CRT/E7 and CRT. Thus, cancer therapy using CRT linked to a tumor antigen holds promise for treating tumors by combining antigen-specific immunotherapy and antiangiogenesis.

Luteolin inhibits the growth and arylamine N-acetyl-transferase activity in Neisseria gonorrhoeae

Growth inhibition and arylamine N-acetyltransferase (NAT) activity in Neisseria gonorrhoeae were inhibited by luteolin, a drug which originated from herbs. The growth inhibition was based on changes in optical density (OD) using a spectrophotometer, and arylamine NAT activity with 2-aminofluorene (2-AF) was determined using high pressure liquid chromatography. The inhibition of growth in N. gonorrhoeae demonstrated that luteolin elicited a dose-dependent growth inhibition in the N. gonorrhoeae cultures. Suspensions of N. gonorrhoeae with or without specific concentrations of luteolin cotreatment showed different percentages of 2-AF acetylation. The data indicated that there was reduced NAT activity associated with increased levels of luteolin in N. gonorrhoeae suspensions. Time-course experiments showed that NAT activity measured from intact N. gonorrhoeae cells was inhibited by luteolin for at least 4 h. Using standard steady-state kinetic analysis, it was demonstrated that luteolin was a possible uncompetitive inhibitor to NAT activity in N. gonorrhoeae. This report is the first to show that luteolin can inhibit N. gonorrhoeae NAT activity.

Luteolin-inhibited arylamine N-acetyltransferase activity and DNA-2-aminofluorene adduct in human and mouse leukemia cells

N-Acetyltransferase enzyme is an important enzyme in the first step of arylamine compounds metabolism. Luteolin has been shown to exit antibacterial and antineoplastic activity. The purpose of this present study is to evaluate the question of whether luteolin could affect arylamine N-acetyltransferase (NAT) activity and DNA-2-aminofluorene adduct formation in human (HL-60) and mouse (L1210) leukemia cells. By using HPLC, N-acetylation of 2-aminofluorene was determined. Luteolin displayed a dose-dependent inhibition to cytosolic NAT activity and intact human and mice leukemia cells. Time-course experiments showed that N-acetylation of 2-aminofluorene measured from intact human and mice leukemia cells were inhibited by luteolin for up to 24 hours. Using standard steady-state kinetic analysis, it was demonstrated that luteolin was a possible uncompetitive inhibitor to NAT activity in cytosols. The DNA-2-aminofluorene adduct formation in human and mouse leukemia cells were inhibited by luteolin. This report is the first demonstration to show that luteolin affects human and mice leukemia cells NAT activity and DNA-2-aminofluorene on adduct formation.

Angiomyolipoma of the liver

BACKGROUND AND OBJECTIVES

Angiomyolipoma is a rare benign tumor that occurs in the liver and other organs. We provide data on eight cases of hepatic angiomyolipoma, regarding clinical presentations, diagnoses, management, and prognosis.

METHODS

A retrospective review of medical records of the eight patients with hepatic angiomyolipoma treated at the Chang Gung Memorial Hospital-Taipei between October 1988 and October 1999.

RESULTS

Eight female patients with hepatic angiomyolipoma were identified, with ages ranging from 30 to 66 years (mean, 45.3 years). Abdominal pain was the most common symptom, occurring in six of eight patients (75%). Hepatocellular carcinoma was the most common preoperative diagnosis, occurring in three of eight patients (37.5%). Laparotomy was performed in seven of eight patients (87.5%). Among these seven patients, three patients (43%) received hepatic resection with 100% cure rate to date. One of the eight patients (12.5%) was closely follow up after diagnosis made by echo-guided needle biopsy.

CONCLUSIONS

Hepatic angiomyolipoma is a rare and benign entity. It has a wide variation and poses a diagnostic challenge clinically, radiologically, and pathologically. Its prognosis is good regardless of management, including hepatic resection or conservative treatment after tissue biopsy by echo-guided needle. To alleviate the mass effect, surgical resection may be needed for hepatic angiomyolipoma in selected cases.

Inhibitory actions of luteolin on the growth and arylamine N-acetyltransferase activity in strains of Helicobacter pylori from ulcer patients

Helicobacter pylori is now recognized as an important cause of type B gastritis, which is strongly associated with gastric and duodenal ulcer disease. H. pylori may be a causative factor in patients with gastric cancer. The growth inhibition and N-acetylation of 2-Aminofluorene (AF) or P-aminobenzoic acid (PABA) by arylamine N-acetyltransferase (NAT) in H. pylori were inhibited by luteolin, a component in herbal medicine. The growth inhibition was based on the changes of optical density (OD) by using a spectrophotometer. The N-acetylation of AF or PABA by NAT from H. pylori were assayed by the amounts of acetylated and non-acetylated AF or PABA in cytosols and intact bacteria of H. pylori by using HPLC. An inhibition of growth on H. pylori demonstrated that luteolin elicited a dose-dependent growth inhibition in the H. pylori cultures. Cytosols and suspensions of H. pylori with or without specific concentrations of luteolin co-treatment showed different percentages of AF or PABA acetylation. The data indicated that there was decreased NAT activity associated with increased levels of luteolin in H. pylori cytosols and suspensions. Using standard steady-state kinetic analysis, it was demonstrated that luteolin was a possible uncompetitive inhibitor to NAT enzyme in H. pylori. This report is the first demonstration to show that luteolin can inhibit H. pylori growth and NAT activity.

Enhancement of Sindbis virus self-replicating RNA vaccine potency by linkage of Mycobacterium tuberculosis heat shock protein 70 gene to an antigen gene

Recently, self-replicating RNA vaccines (RNA replicons) have emerged as an effective strategy for nucleic acid vaccine development. Unlike naked DNA vaccines, RNA replicons eventually cause lysis of transfected cells and therefore do not raise the concern of integration into the host genome. We evaluated the effect of linking human papillomavirus type 16 E7 as a model Ag to Mycobacterium tuberculosis heat shock protein 70 (HSP70) on the potency of Ag-specific immunity generated by a Sindbis virus self-replicating RNA vector, SINrep5. Our results indicated that this RNA replicon vaccine containing an E7/HSP70 fusion gene generated significantly higher E7-specific T cell-mediated immune responses in vaccinated mice than did vaccines containing the wild-type E7 gene. Furthermore, our in vitro studies demonstrated that E7 Ag from E7/HSP70 RNA replicon-transfected cells can be processed by bone marrow-derived dendritic cells and presented more efficiently through the MHC class I pathway than can wild-type E7 RNA replicon-transfected cells. More importantly, the fusion of HSP70 to E7 converted a less effective vaccine into one with significant potency against E7-expressing tumors. This antitumor effect was dependent on NK cells and CD8(+) T cells. These results indicated that fusion of HSP70 to an Ag gene may greatly enhance the potency of self-replicating RNA vaccines.

Improving vaccine potency through intercellular spreading and enhanced MHC class I presentation of antigen

The potency of naked DNA vaccines is limited by their inability to amplify and spread in vivo. VP22, a HSV-1 protein, has demonstrated the remarkable property of intercellular transport and may thus provide a unique approach for enhancing vaccine potency. Therefore, we created a novel fusion of VP22 with a model Ag, human papillomavirus type 16 E7, in a DNA vaccine that generated enhanced spreading and MHC class I presentation of AG: These properties led to a dramatic increase in the number of E7-specific CD8(+) T cell precursors in vaccinated mice (around 50-fold) and converted a less effective DNA vaccine into one with significant potency against E7-expressing tumors. In comparison, nonspreading VP22(1-267) mutants failed to enhance vaccine potency. Our data indicated that the potency of DNA vaccines may be dramatically improved through intercellular spreading and enhanced MHC class I presentation of Ag.

Cancer immunotherapy using a DNA vaccine encoding the translocation domain of a bacterial toxin linked to a tumor antigen

Certain domains of bacterial toxins have been shown to facilitate translocation from extracellular and vesicular compartments into the cytoplasm. This feature represents an opportunity to enhance class I presentation of exogenous antigen to CD8(+) T cells. We investigated this notion by creating a novel fusion of the translocation domain (domain II) of Pseudomonas aeruginosa exotoxin A (ETA(dII)) with a model tumor antigen, human papillomavirus type 16 E7, in the context of a DNA vaccine. Our in vitro studies indicated that cells transfected with ETA(dII)/E7 DNA or dendritic cells pulsed with lysates containing ETA(dII)/E7 protein exhibited enhanced MHC class I presentation of E7 antigen. Vaccination of mice with ETA(dII)/E7 DNA generated a dramatic increase in the number of E7-specific CD8(+) T cell precursors ( approximately 30-fold compared with wild-type E7 DNA) and converted a less effective DNA vaccine into one with significant potency against human papillomavirus type 16 E7-expressing murine tumors via a CD8-dependent pathway. These results indicate that fusion of the translocation domain of a bacterial toxin to an antigen may greatly enhance vaccine potency.

Angiomyolipoma of the liver: case report

Hepatic angiomyolipoma is a rare benign mesenchymal tumor of the liver. Most multiple hepatic angiomyolipomas have appeared in patients with renal angiomyolipoma and tuberous sclerosis. A 38-year-old female patient without chronic hepatitis B or C was hospitalized because of epigastric fullness for 2 months. Radiologic studies showed a large solid tumor with a small daughter nodule in the right hepatic lobe. Upon intravenous bolus injection of contrast medium, both tumors showed weak heterogeneous enhancement in the delayed phase. Although hepatocellular carcinoma was suspected by the findings of computed tomography, percutaneous transhepatic ultrasound-guided biopsy was performed for the large tumor. The histopathology showed many mature fat cells intermingled with thick-walled blood vessels, and epithelioid cells with eosinophilic cytoplasm; the epithelioid cells stained positively for HMB-45 and smooth muscle actin. Angiomyolipoma of the liver was confirmed. The main tumor enlarged considerably during a follow-up period of 3 years. Surgical resection was performed due to persistent symptoms. She had an uneventful postoperative recovery and was well when followed up 10 months after surgery. We should be aware that a hepatic angiomyolipoma can change in size during its natural course, and this finding does not necessarily indicate malignancy.

Enhancement of suicidal DNA vaccine potency by linking Mycobacterium tuberculosis heat shock protein 70 to an antigen

Naked DNA vaccines represent an attractive approach for generating antigen-specific immunity because of their stability and simplicity of delivery. There are particular concerns with DNA vaccines however, such as potential integration into the host genome, cell transformation, and limited potency. The usage of DNA-based alphaviral RNA replicons (suicidal DNA vectors) may alleviate the concerns of integration or transformation since suicidal DNA vectors eventually cause lysis of transfected cells. To improve further the potency of suicidal DNA vaccines, we evaluated the effect of linking Mycobacterium tuberculosis heat shock protein 70 (Hsp70) to human papillomavirus type 16 (HPV-16) E7 as a model antigen on antigen-specific immunity generated by a DNA-based Semliki Forest virus (SFV) RNA vector, pSCA1. Our results indicated that this suicidal DNA vaccine containing E7/Hsp70 fusion genes generated significantly higher E7-specific T cell-mediated immune responses than vaccines containing the wild-type E7 gene in vaccinated mice. More importantly, this fusion converted a less effective vaccine into one with significant potency against established E7-expressing metastatic tumors. The antitumor effect was predominantly CD8-dependent. These results indicate that linkage of Hsp70 to the antigen may greatly enhance the potency of suicidal DNA vaccines.

Effects of the butylated hydroxyanisole and butylated hydroxytoluene on the DNA adduct formation and arylamines N-acetyltransferase activity in human colon tumor cells

The effects of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on N-acetyltransferase (NAT) activity were examined using a human colon tumor cell line (colo 205). BHA or BHT were added to the cytosols or to the medium of human colon tumor cells: The NAT activity was measured by high performance liquid chromatography, assaying the amounts of acetylated 2-aminoflluorene (AAF), p aminobenzoic acid (N-Ac-PABA), nonacetylated 2 aminofluorene (AF) and p-aminobenzoic acid (PABA). The NAT activity in the human colon tumor cells and cytosols was suppressed by BHA or BHT in a dose-dependent manner. The apparent values of Km and Vmax of NAT of human colon tumor cells were also decreased by BHA or BHT in cytosols and in intact cells. BHA or BHT may act as a noncompetitive inhibitor. After the incubation of human colon tumor cells with AF in the presence of BHA or BHT, the cells were recovered and DNA was prepared and hydrolysed to nucleotides. Adducted nucleotides were extracted into butanol and AF-DNA adducts were analysed by HPLC. The results also demonstrated that when BHA or BHT was added to the media, a decrease in AF-DNA adduct formation was seen in the human colon tumor cells. The finding of AF-DNA adduct formation in cultured human colon tumor cells suggest the possibility of using cultured cells for assessing arylamine-induced DNA damage.

Icteric-type hepatoma: magnetic resonance imaging and magnetic resonance cholangiographic features

BACKGROUND

We evaluated the imaging features of magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRC) of icteric-type hepatoma and correlated these with the findings of endoscopic retrograde cholangiography (ERC), percutaneous cholangiography, and surgery.

METHODS

Thirteen patients with viral hepatitis complicated by cirrhosis of the liver and obstructive jaundice underwent MRC and dynamic MRI. Five patients received percutaneous transhepatic cholangiography and drainage; one of these patients also underwent resection of the left hepatic lobe. Another patient received MRC followed by thrombectomy and T-tube insertion. ERC and endoscopic nasobiliary drainage were performed in another patient for bile diversion.

RESULTS

Primary liver tumors and dilatation of biliary system were demonstrated in all patients. No capsule formation could be found in any primary liver tumors. MRI showed the simultaneous presence of an intraluminal tumor in the portal trunk and common hepatic duct in eight patients. Three different MRC features were found: (a) an oval defect in the hilar bile duct(s) with dilated intrahepatic ducts (n = 9), (b) dilated intrahepatic ducts with missing major bile ducts (n = 2), and (c) localized stricture of the hilar bile duct(s) (n = 2).

CONCLUSION

The presence of one or more of the following features in multiplanar MRI and MRC help to identify this rare, specific type of hepatocellular carcinoma: (a) the presence of an intraluminal tumor in both the portal trunk and the common hepatic duct, (b) enhancement of the intraluminal tumor in the common hepatic duct on the arterial phase, (c) type I MRC feature, and (d) hemobilia, blood clot within the gallbladder, and/or type II MRC feature.

Effects of carmustine on aminofluorene-DNA adducts formation in rat glial tumor cells

Arylamine-DNA adducts formation in tissues has been correlated with the carcinogenic effect of heterocyclic aromatic amines. Carmustine (BCNU) is a commercially available nitrosourea derivative and chloroethyl nitrosourea compound which is applied in anti-neoplastic therapy especially in central nervous system. The effects of carmustine on Aminofluorene-DNA (AF-DNA) formation in rat glioma cells were investigated by gamma-[32p]-dATP and high performance liquid chromatography (HPLC) using 2-aminofluorene (AF) as substrate. In the presence of 8 microM carmustine, the AF-DNA adduct formation was decreased 10.6% and 15.6% in 30 microM and 60 microM of AF (p < 0.05), respectively; In the presence of 80 microM carmustine the AF-DNA adduct formation was decreased 39.6% and 40% in 30 microM and 60 microM of AF (p < 0.02), respectively. These results show that BCNU could decrease AF-DNA formation in rat glial tumor cells.

Effects of berberine on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adduct formation in human leukemia cells

Berberine is an alkaloid occurring in the plant genera Berberis and Coptis. Although berberine had been demonstrated to have antineoplastic function by inhibiting DNA-synthesis in activated lymphocytes, there is no available information to address berberine affects on human leukemia cell N-acetyltransferase (NAT) activity and 2-aminofluorene (AF)-DNA adduct formation. Thus, berberine was tested for inhibition of arylamine NAT activity and AF-DNA adduct formation in human leukemia cells. The NAT activity was measured by a high performance liquid chromatography assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and the remaining AF and p-aminobenzoic acid (PABA). The NAT activity and AF-DNA adduct formation in human leukemia cells were inhibited by berberine in a dose-dependent manner, i.e. the higher the concentration of berberine, the higher the inhibition of NAT activity and AF-DNA adduct. The data also indicate that berberine decreased the apparent values of Km and Vmax from human leukemia cells in both cytosol and intact cells.

Enhancement of sindbis virus self-replicating RNA vaccine potency by targeting antigen to endosomal/lysosomal compartments

Self-replicating RNA vaccines (RNA replicons) have emerged as an attractive approach for tumor immunotherapy. RNA replicons do not integrate into host chromosomes, eliminating the concern for oncogenicity associated with a DNA vaccine. In this study, we used human papillomavirus type 16 (HPV-16) E7 as a model antigen and evaluated E7-specific immunity generated by a Sindbis virus self-replicating RNA vector, SIN-rep5. Three different constructs were created to target E7 antigen to different cellular localizations: (1) E7, a cytosolic/nuclear protein; (2) Sig/E7, a secretory protein; (3) Sig/E7/LAMP-1, in which we linked the transmembrane and cytoplasmic regions of the lysosome-associated membrane protein 1 (LAMP-1) to E7 protein to target E7 to the endosomal/lysosomal compartment. We found that the RNA replicon vaccine containing the Sig/E7/LAMP-1 fusion gene generated the highest E7-specific T cell-mediated immune responses and antitumor effects relative to RNA vaccines containing either wild-type E7 or Sig/E7. Our in vitro studies demonstrated that E7 antigen from Sig/E7/LAMP-1 RNA replicon-transfected apoptotic cells can be taken up by bone marrow-derived dendritic cells (DCs) and presented more efficiently through the MHC class I pathway than wild-type E7 RNA replicon-transfected apoptotic cells. Furthermore, our data revealed that CD8(+) T cells, CD4(+) T cells, and NK cells were important for the antitumor effects generated by Sig/E7/LAMP-1 RNA vaccination. These results indicate that targeting antigen to the endosomal/lysosomal compartment via fusion to LAMP-1 may greatly enhance the potency of self-replicating RNA vaccines.

Enhancement of DNA vaccine potency by linkage of antigen gene to a gene encoding the extracellular domain of Fms-like tyrosine kinase 3-ligand

Recently, Flt3 (Fms-like tyrosine kinase 3)-ligand has been identified as an important cytokine for the generation of professional antigen-presenting cells (APCs), particularly dendritic cells (DCs). A recombinant chimera of the extracellular domain of Flt3-ligand (FL) linked to a model antigen may potentially target the antigen to DCs and their precursor cells. Using human papillomavirus-16 E7 as a model antigen, we evaluated the effect of linkage to FL on the potency of antigen-specific immunity generated by naked DNA vaccines administered intradermally via gene gun. We found that vaccines containing chimeric FL-E7 fusion genes significantly increased the frequency of E7-specific CD8+ T cells relative to vaccines containing the wild-type E7 gene. In vitro studies indicated that cells transfected with FL-E7 DNA presented E7 antigen through the MHC class I pathway more efficiently than wild-type E7 DNA. Furthermore, bone marrow-derived DCs pulsed with cell lysates containing FL-E7 fusion protein presented E7 antigen through the MHC class I pathway more efficiently than DCs pulsed with cell lysates containing wild-type E7 protein. More importantly, this fusion converted a less effective vaccine into one with significant potency against established E7-expressing metastatic tumors. The FL-E7 fusion vaccine mainly targeted CD8+ T cells, and antitumor effects were completely CD4 independent. These results indicate that fusion of a gene encoding the extracellular domain of FL to an antigen gene may greatly enhance the potency of DNA vaccines via CD8-dependent pathways.

Recombinant DNA vaccines protect against tumors that are resistant to recombinant vaccinia vaccines containing the same gene

Antigen-specific cancer immunotherapy involves the delivery of tumor-associated antigen to the host for the generation of tumor-specific immune responses and antitumor effects. We hypothesized that different delivery systems may influence the pattern of antigen-specific immune response and the outcome of antitumor effect. We therefore evaluated recombinant vaccinia virus and naked DNA for the generation of antigen-specific immune responses and antitumor effects. We previously found that recombinant vaccinia and naked DNA vaccines containing the chimeric Sig/E7/LAMP-1 gene were capable of controlling the growth of HPV-16 E7-expressing tumor cells (TC-1). In this study, we performed a head-to-head comparison of optimized delivery of Sig/E7/LAMP-1 vaccinia and DNA vaccines using dose-escalating tumor challenge. At a dose of 1 x 10(6) TC-1 cells per mouse, Sig/E7/LAMP-1 DNA provided 100% protection against subcutaneous growth of tumors, while Vac-Sig/E7/LAMP-1 protected only 40% of the mice. Furthermore, Sig/E7/LAMP-1 DNA vaccines are capable of protecting against challenge with a more stringent subclone of TC-1 (TC-1 P2) established from TC-1 tumors that survived initial Sig/E7/LAMP-1 vaccinia vaccination. Immunological assays revealed that both vaccines induced comparable levels of CD8(+) T cell precursors and anti-E7 antibody titers. Interestingly, Sig/E7/LAMP-1 vaccinia induced both E7-specific IFN-gamma- and IL4-secreting CD4(+) T cell precursors while Sig/E7/LAMP-1 DNA induced only E7-specific IFN-gamma-secreting CD4(+) T cell precursors. We also found that IL-4 knockout C57BL/6 mice vaccinated with Sig/E7/LAMP-1 vaccinia exhibited a more potent antitumor effect than vaccinated wild-type C57BL/6 mice in our tumor protection experiments. These results suggest that IL-4 may play a detrimental role in the antitumor effect mediated by vaccinia vaccines. Our findings suggested that DNA vaccines may provide better tumor protection than vaccinia vaccines employing the same gene, which may have implications in the future design of antigen-specific cancer immunotherapy.

Effects of ellagic acid by oral administration on N-acetylation and metabolism of 2-aminofluorene in rat brain tissues

Numerous studies have demonstrated that the Acetyl Coenzyme A-dependent arylamine NAT enzyme exist in many tissues of experimental animals including humans, and that NAT has been shown to be exist in mouse brain tissue. Increased NAT activity levels are associated with increased sensitivity to the mutagenic effects of arylamine carcinogens. Attenuation of liver NAT activity is related to breast and bladder cancer processes. Therefore, the effects of ellagic acid (EA) on the in vitro and in vivo N-acetylation of 2-aminofluorene (AF) were investigated in cerebrum, cerebellum and pineal gland tissues from male Sprague-Dawley rats. For in vitro examination, cytosols with or without EA (0.5-500 microM) co-treatment decreased 7-72%, 15-63% and 10-78% of AF acetylation for cerebrum, cerebellum and pineal gland tissues, respectively. For in vivo examination, EA and AF at the same time treated groups with all 3 examined tissues did show significant differences (the changes of total amounts of AF and AF metabolites based on the Anova analysis) when compared to the ones without EA cotreatment rats. The pretreatment of male rats with EA (10 mg/kg) 24 hr prior to the administration of AF (50 mg/kg) (one day of EA administration suffice to induce large changes in phase II enzyme activity) resulted in a 76% decrease in total AF and metabolites in pineal gland but did not show significant differences in cerebrum and cerebellum tissues. This is the first demonstration to show that EA decreases the N-acetylation of carcinogens in rat brain tissues.

Effects of butylated hydroxyanisole and butylated hydroxytoluene on DNA adduct formation and arylamines N-acetyltransferase activity in PC-3 cells (human prostate tumor) in vitro

The effects of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on the N-acetyltransferase (NAT) activity and DNA adduct formation in PC-3 cells (human prostate tumor) was studied. PC-3 cells were placed into tissue culture flasks and grown in an incubator as cytosols and intact cells. The BHA or BHT were added to the cytosols and intact cells. The NAT activity in cytosol and intact PC-3 cells were measured by HPLC assaying exhibited for the amounts of N-acetyl-2-aminofluorene and N-acetyl-p-aminobenzoic acid, 2-aminofluorene and p-aminobenzoic acid. The NAT activity in PC-3 cells and cytosols were inhibited by BHA or BHT in a dose-dependent manner; that is, the higher the concentrations of BHA or BHT the higher inhibition of NAT activity. The NAT values of K(m) and V(max) from PC-3 cells were also decreased by BHA or BHT in both cytosols and intact cells. The data also demonstrated concomitant exposure to BHA or BHT decreased AF-DNA adduct formation which was seen in the PC-3 cells. In addition, the formation of DNA adduct was decreased after BHA or BHT exposure. These findings suggested the usefulness of using human cultured PC-3 cells for assessing arylamine-induced DNA adduct formation. Furthermore, the findings illustrate how effectively BHA or BHT reduce the adduct formation.

Human 3alpha-hydroxysteroid dehydrogenase isoforms (AKR1C1-AKR1C4) of the aldo-keto reductase superfamily: functional plasticity and tissue distribution reveals roles in the inactivation and formation of male and female sex hormones

The kinetic parameters, steroid substrate specificity and identities of reaction products were determined for four homogeneous recombinant human 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) isoforms of the aldo-keto reductase (AKR) superfamily. The enzymes correspond to type 1 3alpha-HSD (AKR1C4), type 2 3alpha(17beta)-HSD (AKR1C3), type 3 3alpha-HSD (AKR1C2) and 20alpha(3alpha)-HSD (AKR1C1), and share at least 84% amino acid sequence identity. All enzymes acted as NAD(P)(H)-dependent 3-, 17- and 20-ketosteroid reductases and as 3alpha-, 17beta- and 20alpha-hydroxysteroid oxidases. The functional plasticity of these isoforms highlights their ability to modulate the levels of active androgens, oestrogens and progestins. Salient features were that AKR1C4 was the most catalytically efficient, with k(cat)/K(m) values for substrates that exceeded those obtained with other isoforms by 10-30-fold. In the reduction direction, all isoforms inactivated 5alpha-dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-one; 5alpha-DHT) to yield 5alpha-androstane-3alpha,17beta-diol (3alpha-androstanediol). However, only AKR1C3 reduced Delta(4)-androstene-3,17-dione to produce significant amounts of testosterone. All isoforms reduced oestrone to 17beta-oestradiol, and progesterone to 20alpha-hydroxy-pregn-4-ene-3,20-dione (20alpha-hydroxyprogesterone). In the oxidation direction, only AKR1C2 converted 3alpha-androstanediol to the active hormone 5alpha-DHT. AKR1C3 and AKR1C4 oxidized testosterone to Delta(4)-androstene-3,17-dione. All isoforms oxidized 17beta-oestradiol to oestrone, and 20alpha-hydroxyprogesterone to progesterone. Discrete tissue distribution of these AKR1C enzymes was observed using isoform-specific reverse transcriptase-PCR. AKR1C4 was virtually liver-specific and its high k(cat)/K(m) allows this enzyme to form 5alpha/5beta-tetrahydrosteroids robustly. AKR1C3 was most prominent in the prostate and mammary glands. The ability of AKR1C3 to interconvert testosterone with Delta(4)-androstene-3,17-dione, but to inactivate 5alpha-DHT, is consistent with this enzyme eliminating active androgens from the prostate. In the mammary gland, AKR1C3 will convert Delta(4)-androstene-3,17-dione to testosterone (a substrate aromatizable to 17beta-oestradiol), oestrone to 17beta-oestradiol, and progesterone to 20alpha-hydroxyprogesterone, and this concerted reductive activity may yield a pro-oesterogenic state. AKR1C3 is also the dominant form in the uterus and is responsible for the synthesis of 3alpha-androstanediol which has been implicated as a parturition hormone. The major isoforms in the brain, capable of synthesizing anxiolytic steroids, are AKR1C1 and AKR1C2. These studies are in stark contrast with those in rat where only a single AKR with positional- and stereo-specificity for 3alpha-hydroxysteroids exists.

Inhibition by vitamin C of DNA adduct formation and arylamine N-acetyltransferase activity in human bladder tumor cells

Previous studies have already demonstrated the protective role of vitamin C (ascorbic acid) in certain types of cancer. This study reports on the effects of vitamin C on arylamine N-acetyltransferase (NAT) activity and DNA adduct formation in a human bladder tumor cell (T24) line. The activity of NAT was measured using high-performance liquid chromatography (HPLC), by assaying for the amounts of acetylated 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) and the remaining amounts of AF and PABA. T24 cells were used for examining NAT activity and carcinogen DNA adduct formation. The results demonstrated that NAT activity and 2-aminofluorene DNA adduct formation in T24 cells were inhibited and decreased by vitamin C in a dose-dependent manner. The apparent kinetic parameters (apparent values of Km and Vmax) from T24 cells were also determined with and without vitamin C cotreatment. The data also indicated that vitamin C decreased the apparent values of Km and Vmax from T24 cells.

Identification of opioid receptors in the sympathetic and parasympathetic nerves of guinea-pig atria

The opioid receptor subtypes of autonomic nerves of guinea-pig atria were elucidated by monitoring the effects of selective opioid receptor agonists on the negative and positive inotropic responses associated with the stimulation of the parasympathetic and sympathetic nerves, respectively. The positive inotropic effect, evoked by electrical field stimulation (2 Hz) was strongly reduced by the selective OP2-opioid receptor agonists U-50488 and U-69593, but partly by the OP3-opioid receptor agonist morphine. This effect of U-50488 and U-69593 were reversed by the selective OP2-opioid receptor antagonist nor-BNI. The effect of morphine was partly reversed by naloxone, whereas OP1-opioid receptor agonists, BW373 U86 and DPDPE, were ineffective. On the other hand, the negative inotropic response to electrical field stimulation was not affected by opioid receptor agonists. These results suggest that the noradrenaline release from cardiac sympathetic nerves of guinea-pig could be modulated, mainly by the OP2-opioid receptor, however, the acetylcholine release from cardiac parasympathetic nerves is not modulated by opioid receptors.

Effects of carmustine and lomustine on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adducts in rat glial tumor cells

Carmustine and lomustine are nitrosourea antitumor chemotherapeutic agents which were used to determine whether or not they could affect arylamine N-acetyltransferase (NAT) activity and DNA-2-aminofluorene adducts in rat glial tumor cell line (C6 glioma). The NAT activity was measured by high preformance liquid chromatography (HPLC) assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and remaining 2-aminofluorene (AF) and p-aminobenzoic acid (PABA). The results indicate that NAT activity in glial tumor cell cytosols and intact tumor cells were decreased by carmustine and lomustine in a dose-dependent manner. The apparent values of Km and Vmax of NAT from rat glial tumor cell also decreased after co-treatment of carmustine and lomustine in both examined cytosols and intact cells. Following exposure of glial tumor cells to the various concentrations of AF with or without co-treatment with carmustine and lomustine, DNA-AF adducts were determined by using gamma-[32p]-dATP and HPLC. The DNA-AF adducts in rat glial tumor cells were decreased by co-treatment with carmustine and lomustine. This report is the first demonstration to show carmustine and lomustine did inhibit rat glial tumor cells NAT activity and DNA-AF adduct formation.

Female lung cancer mortality and sex ratios at birth near a petroleum refinery plant

This study was conducted to assess whether female mortality from lung cancer is associated with residence in communities adjacent to a petroleum refinery plant and whether petroleum air pollution could affect the sex ratios of births. The Kaohsiung Refinery of the Chinese Petroleum Corp. is the oldest oil refinery in Taiwan and is located between the Tso-Ying and the Nan-Tzu municipalities. Standardized mortality ratios (SMRs) for female lung cancer and sex ratios of births were calculated for each municipality for the years 1971-1996. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. The study results show that mortality from female lung cancer rose gradually about 30 to 37 years after the operation of a petroleum refinery plant began. However, the association between exposure to the petroleum air pollution and abnormal sex ratios at birth was not significant.

Arylamine N-acetyltransferase activity and 2 aminofluorene-DNA adducts formation in rat glial tumor cells

Arylamine N-acetylation capacity by the N-acetyltransferase (NAT) may be an important causative factor in the initiation of cancer. Arylamine-DNA adducts formation have been correlated with the carcinogenic effect of heterocyclic aromatic amines. NAT activity in rat glial tumor cells was measured by high performance liquid chromatography (HPLC) using 2-aminofluorene (2-AF) and p-aminobenzoic acid (PABA) as substrares. 2-AF-DNA adducts formation in rat glial tumor cells was investigated by gamma-[32p]-dATP and HPLC using 2-aminofluorene as substrates. The activities (Mean +/- SD) of NAT in rat glial cells was 1.08 +/- 0.18 nmol/min/mg protein for the acetylation of 2-aminofluorene (n = 12), and 0.96 +/- 0.16 nmol/min/mg protein for the acetylation of p-aminobenzoic acid (n = 12). 2-AF-DNA adducts formation in rat glial tumor cells with 30 microM and 60 microM AF were 0.48 +/- 0.16 and 0.70 +/- 0.12 pmol/mg DNA, respectively. The results indicate that NAT was present in rat glial tumor cells, activating AF to become a metabolite able to bind covalently with DNA to form 2-AF-DNA.

Boosting with recombinant vaccinia increases HPV-16 E7-specific T cell precursor frequencies of HPV-16 E7-expressing DNA vaccines

We have previously linked the sorting signals of the lysosome-associated membrane protein-1 (LAMP-1) to HPV-16 E7 antigen, creating a chimera, Sig/E7/LAMP-1. We found that both Sig/E7/LAMP-1-containing recombinant vaccinia virus (Vac-Sig/E7/LAMP-1) and Sig/E7/LAMP-1 DNA can generate strong antitumor immunity. To determine whether combination of Sig/E7/LAMP-1 DNA and Vac-Sig/E7/LAMP-1 can further enhance immune responses, sequential vaccination with Sig/E7/LAMP-1 DNA and Vac-Sig/E7/LAMP-1 was given. We found that priming with Sig/E7/LAMP-1 DNA and boosting with Vac-Sig/E7/LAMP-1 generated the strongest E7-specific CD8(+) T cell responses. Our results encourage the use of the DNA prime/vaccinia booster regimen in future clinical trials.

Effects of caffeic acid, chlorogenic acid and ferulic acid on growth and arylamine N-acetyltransferase activity in Shigella sonnei (group D)

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene (2-AF) as substrates were determined in Shigella sonnei (group D) collected from patients with diarrhoeal disease. The NAT activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. Inhibition of growth studies from S. sonnei (group D) demonstrated that caffeic acid (CA), chlorogenic acid (CGA) and ferulic acid (FA) elicited a dose-dependent bactericidal effect in S. sonnei (group D) cultures, i.e. the greater the concentration of CA, CGA and FA, the greater the inhibition of growth of S. sonnei (group D). Cytosols or suspensions of S. sonnei (group D) with and without selected concentrations of CA, CGA and FA co-treatment showed different percentages of 2-AF acetylation. The data indicated that there was reduced NAT activity associated with increased CA, CGA and FA in Shigella dysenteriae (group D) cytosols and intact cells. For the cytosol and intact bacteria examinations, the apparent values of K(m) and Vmax decreased after being co-treated with 400 microM CA, CGA and FA. This report is the first demonstration of plant phenolic inhibition (CA, CGA and FA) of arylamine NAT activity and growth in the bacterium S. sonnei (group D).

Fluoride in drinking water and cancer mortality in Taiwan

The possibility that cancer risk is associated with naturally fluoridated water in Taiwan is examined. The 1982-1991 age-adjusted mortality rates for cancer for 10 municipalities whose water supplies contained the highest naturally occurring fluoride concentrations in Taiwan were compared to those rates for 10 matched municipalities with unfluoridated water. The two groups had similar urbanization levels and sociodemographic characteristics. Our study does not support the suggestion that fluoridation of water supplies is associated with an increase in cancer mortality in Taiwan.

Enhancement of DNA vaccine potency by linkage of antigen gene to an HSP70 gene

Nucleic acid vaccines represent an attractive approach to generating antigen-specific immunity because of their stability and simplicity of delivery. However, there is still a need to increase the potency of DNA vaccines. Using human papillomavirus type 16 E7 as a model antigen, we evaluated the effect of linkage to Mycobacterium tuberculosis heat shock protein 70 (HSP70) on the potency of antigen-specific immunity generated by naked DNA vaccines. We found that vaccines containing E7-HSP70 fusion genes increased the frequency of E7-specific CD8+ T cells by at least 30-fold relative to vaccines containing the wild-type E7 gene. More importantly, this fusion converted a less effective vaccine into one with significant potency against established E7-expressing tumors. Surprisingly, E7-HSP70 fusion vaccines exclusively targeted CD8+ T cells; immunological and antitumor effects were completely CD4-independent. These results indicate that fusion of HSP70 to an antigen gene may greatly enhance the potency of DNA vaccines via CD8-dependent pathways.