Establishment of an oral squamous cell carcinoma cell line expressing vascular endothelial growth factor a and its two receptors

Background/purpose

Vascular endothelial growth factor receptor (VEGFR) expression in oral squamous cell carcinoma (OSCC) promotes tumor growth through both autocrine and paracrine signaling. VEGF-positive OSCC cases are associated with a high depth of invasion, increased metastasis, and poor prognosis. In this study we established and then molecularly and functionally analyzed an OSCC cell line that co-expresses VEGF-A, VEGFR-1, and VEGFR-2, termed HCM-SqCC010 cells.

Materials and methods

VEGF-A, VEGFR-1, and VEGFR-2 expression in HCM-SqCC010 cells were examined by immunohistochemistry and immunoblotting. Expression and inhibition of VEGF-A, VEGFR-1, and VEGFR-2 in HCM-SqCC010 cells were verified by quantitative real-time PCR.

Results

Our analysis of HCM-SqCC010 cells revealed that their proliferation depended on VEGF-A, and selective inhibition of VEGFR-1 or VEGFR-2 resulted in decreased cell growth.

Conclusion

We established an OSCC cell line, HCM-SqCC010, that expresses VEGF-A, VEGFR-1, and VEGFR-2. This triple-positive cell line showed no effect from a molecular targeted drug toward VEGF-A, but it did show strong cell growth inhibition in response to a VEGFR inhibitor. Thus, new therapeutic strategies against OSCC should include a VEGFR inhibitor.

Iron-induced calcification in human aortic vascular smooth muscle cells through interleukin-24 (IL-24), with/without TNF-alpha

In CKD patients, arteriosclerotic lesions, including calcification, can occur in vascular smooth muscle cells in a process called Moenckeberg's medial arteriosclerosis. Iron overload induces several complications, including the acceleration of arteriosclerosis. However, the relationship between Moenckeberg's arteriosclerosis in vascular smooth muscle cells and iron accumulation has remained unknown. We tested the accelerated effect of iron on calcification in cultured human aortic vascular smooth muscle cells (HASMCs). After establishment of this model, we performed a microarray analysis using mRNA from early stage culture HASMCs after iron stimulation with or without TNF-alpha stimulation. The role of interleukin-24 (IL-24) was confirmed from candidate genes that might contribute to calcification. HASMCs demonstrated calcification induced by iron and TNF-alpha. Calcification of HASMCs was synergistically enhanced by stimulation with both iron and TNF-alpha. In the early phase of calcification, microarray analysis revealed up-regulation of IL-24. Stimulation of HASMCs by IL-24 instead of iron induced calcification. The anti-IL-24 antibody reversed the effect of IL-24, supporting the important role of IL-24 in HASMCs calcification. In conclusion, iron-induced calcification in vascular smooth muscle cells occurred via IL-24, IL-24 was increased during the calcification process induced by iron, and IL-24 itself caused calcification in the absence of iron.

Clinicopathologic Impact of Early Medullary Ray Injury in Patients Following Kidney Transplantation

BACKGROUND

Previously, we explored the histopathologic characteristics of medullary ray injury (MRI) inducing interstitial fibrosis and tubular atrophy (IF/TA) to determine its etiologies, which include calcineurin inhibitor (CNI) toxicity and urologic complications. However, we did not examine the effects of these etiologies on long-term kidney allograft prognosis, because biopsy timing differed among cases.

AIM

We examined the influence of early MRI on kidney allograft prognosis using protocol biopsies taken within a 3-month time frame.

METHODS

We defined early MRI as tubular degeneration with interstitial edema or mild fibrosis localized to the medullary ray. We divided 53 protocol biopsies into 2 groups, with and without early MRI. Early MRI+ cases with isometric vacuolization were classified as CNI toxicity; those with Tamm-Horsfall protein in the interstitium and a thyroidlike appearance were classified as urinary tract system abnormalities; remaining cases were classified as "others." We compared changes in serum levels of creatinine (sCr) over 3 years and fibrosis extent at 1 year.

RESULTS

The sCr levels were significantly higher in the MRI+ group than the MRI- group at 3 years (P = .024). Examining the 3 MRI+ subgroups, only the MRI+ urinary tract system abnormalities group had significantly high sCr levels compared to the MRI- group (P = .019). The MRI+ group showed significant signs of IF/TA at 1 year.

CONCLUSIONS

Early MRI after kidney transplantation was significantly more likely to develop IF/TA at 1 year and had higher sCr levels at 3 years. In such cases, intervention might preserve graft function over the long term.

RP S19 C-terminal peptide trimer acts as a C5a receptor antagonist

We have demonstrated that ribosomal protein S19 (RP S19) polymer, when crosslinked between Lys122 and Gln137 by activated coagulation factor XIII, acts as a C5a receptor (C5aR) antagonist/agonist. Based on experimental data obtained using RP S19 analog peptide and recombinant protein monomer, we suggested that L₁₃₁DR, I₁₃₄AGQVAAAN and K₁₄₃KH moieties in the RP S19 C‐terminus act in, respectively, C5aR binding, penetration of the plasma membrane, and interaction with either an apoptosis-inducing molecule in neutrophils (delta lactoferrin) or a calcium channel-activating molecule (annexin A3) to induce the p38 MAPK pathway in macrophages. Recently, we observed RP S19 trimer in serum. To study the effects of this RP S19 trimer on C5aR, we prepared mutant RP S19 C‐terminal peptide (RP S19^122-145) dimer and trimer, and examined their chemotactic activities and signal transduction pathways in human C5aR-overexpressing squamous cell carcinoma HSC-1 (HSC-1^C5aR) cells using 24 trans-well chamber and western blotting assays, respectively. HSC-1^C5aR cells were attracted by RP S19^122-145 dimer and vice versa by RP S19^122-145 trimer. The RP S19^122-145 dimer-induced attraction was competitively blocked by pre-treatment with RP S19^122-145 trimer. Moreover, RP S19^122-145 trimer-induced p38 MAPK phosphorylation was stronger than RP S19^122-145 dimer-induced p38 MAPK phosphorylation. RP S19^122-145 trimer appeared to act as a C5aR antagonist. The agonistic and antagonistic effects of RP S19^122-145 dimers and trimers were reflected by monocytic, THP-1-derived macrophage-like cells. Unlike the C5aR agonist C5a, which acts at the inflammation phase of acute inflammation, RP S19 trimer might act as a C5aR antagonist at the resolution phase.

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RP S19 dimer acted as C5aR antagonist/agonist.

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RP S19 dimer induced p38MAPK and ERK1/2 signal.

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RP S19 trimer acted as C5aR antagonist.

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RP S19 trimer induced p38MAPK signal.

Sodium valproate, a histone deacetylase inhibitor, modulates the vascular endothelial growth inhibitor-mediated cell death in human osteosarcoma and vascular endothelial cells

The level of vascular endothelial growth inhibitor (VEGI) has been reported to be negatively associated with neovascularization in malignant tumors. The soluble form of VEGI is a potent anti-angiogenic factor due to its effects in inhibiting endothelial cell proliferation. This inhibition is mediated by death receptor 3 (DR3), which contains a death domain in its cytoplasmic tail capable of inducing apoptosis that can be subsequently blocked by decoy receptor 3 (DcR3). We investigated the effects of sodium valproate (VPA) and trichostatin A (TSA), histone deacetylase inhibitors, on the expression of VEGI and its related receptors in human osteosarcoma (OS) cell lines and human microvascular endothelial (HMVE) cells. Consequently, treatment with VPA and TSA increased the VEGI and DR3 expression levels without inducing DcR3 production in the OS cell lines. In contrast, the effect on the HMVE cells was limited, with no evidence of growth inhibition or an increase in the DR3 and DcR3 expression. However, VPA-induced soluble VEGI in the OS cell culture medium markedly inhibited the vascular tube formation of HMVE cells, while VEGI overexpression resulted in enhanced OS cell death. Taken together, the HDAC inhibitor has anti-angiogenesis and antitumor activities that mediate soluble VEGI/DR3-induced apoptosis via both autocrine and paracrine pathways. This study indicates that the HDAC inhibitor may be exploited as a therapeutic strategy modulating the soluble VEGI/DR3 pathway in osteosarcoma patients.

Annexin A3 plays a role in cytoplasmic calcium oscillation by extracellular calcium in the human promyelocytic leukemia HL-60 cells differentiated by phorbol-12-myristate-13-acetate

The roles of annexin A3 (ANXA3) in macrophages are not fully understood. In contrast to C5a, we have demonstrated that C-terminal ribosomal protein S19 (RP S19)-tagged S-tagged C5a (S-tagged C5a/RP S19) raises an alternative cytoplasmic calcium oscillation by extracellular calcium during macrophage migration into apoptotic cells. We here differentiated human promyelocytic leukemia HL-60 cells bearing with either control sense RNA and shRNA for ANXA3 mRNA or a vector cDNA with or without ANXA3 cDNA into macrophage-like cells by phorbol-12-myristate-13-acetate and found that a fluorescence ratio (340 nm/380 nm) upon the S-tagged C5a/RP S19-induced alternative cytoplasmic calcium oscillation by extracellular calcium was an equilateral association with a dose of ANXA3. Moreover, the ANXA3-dependent modification was partially reflected upon the S-tagged C5a-induced classical cytoplasmic calcium oscillation by both intracellular calcium and extracellular calcium. ANXA3 seems to extend the C5aR-mediated cytoplasmic calcium oscillation by extracellular calcium at least in the HL-60 macrophage-like cells.

Tumor Promotion by 12-O-Tetradecanoylphorbol-13-Acetate in an Ultra-Short-Term Skin Carcinogenesis Bioassay Using rasH2 Mice

Assessment of the skin tumor–promoting potential of 12- O-tetradecanoylphorbol-13-acetate (TPA) after initiation with 7,12-dimethylbenz[ a]anthracene (DMBA) was conducted using rasH2 transgenic (Tg) mice and their nontransgenic (non-Tg) littermates. Mice were treated with DMBA (50 μg/100 μL acetone) on clipped back skin at the commencement of the study, and 1 week thereafter, TPA was applied at 8 μg/200 μL or 4 μg/200 μL acetone, once or twice weekly, for 7 weeks. Skin nodules were observed in the rasH2 Tg mice from week 4, and the incidence reached 100% at weeks 5 and 6. The number of skin nodules (multiplicity) in the 8-μg twice-weekly, 8-μg once-weekly, 4-μg twice-weekly, and 4-μg once-weekly groups was 62.4, 46.2, 62.6, and 36.9, respectively. The non-Tg mice also developed skin nodules, but the sensitivity to induction in the rasH2 Tg mice was higher. No nodules were observed in the acetone groups, but single nodules were apparent in the no-treatment rasH2 Tg and non-Tg groups. In conclusion, skin promotion effects could be detected within only 8 weeks in the rasH2 mice, and the concentration of 4 μg TPA once weekly was sufficient as a positive control. This short-term skin carcinogenesis bioassay using rasH2 mice could represent a useful tool for the assessment of drug and chemical safety with cutaneous treatment.

The promotional effect of IL-22 on mineralization activity of periodontal ligament cells

OBJECTIVES

Interleukin (IL)-22 acts on non-immune cells to induce anti-microbial responses, protection from tissue damage, and enhance cell regeneration. However, little is known about the involvement of IL-22 in periodontal biology. This study investigated the biological effects of IL-22 on periodontal ligament (PDL) cells as part of studies to assess the involvement of IL-22 in periodontal disease.

MATERIALS AND METHODS

Gene expression levels of IL-22 and its receptors in PDL cells and gingival tissue samples were evaluated by real-time PCR. Proliferative responses and mineralized-matrix forming activities of PDL cells were examined in the presence and absence of IL-22.

RESULTS

In contrast to the expression of IL-22 receptors detected in PDL tissues and their cell lines, gingival tissues showed modest or no gene expressions of IL-22. The production of several cytokines including IL-11, IL-8 and CCL2 was upregulated by IL-22 treatment of PDL cells in a dose-dependent manner. IL-22 treatment had no effect on the proliferative response in PDL cells. Meanwhile, IL-22 precipitated mineralized nodule formation and induced gene expressions of RUNX2, MSX2 and osteocalcin in PDL cells, suggesting that IL-22 enhances the mineralized matrix-forming activities of PDL cells.

CONCLUSION

IL-22 has the potential to promote mineralizing activity in PDL cells and to develop appropriate regenerative therapy.

The promotional effect of IL-22 on mineralization activity of periodontal ligament cells

OBJECTIVES

Interleukin (IL)-22 acts on non-immune cells to induce anti-microbial responses, protection from tissue damage, and enhance cell regeneration. However, little is known about the involvement of IL-22 in periodontal biology. This study investigated the biological effects of IL-22 on periodontal ligament (PDL) cells as part of studies to assess the involvement of IL-22 in periodontal disease.

MATERIALS AND METHODS

Gene expression levels of IL-22 and its receptors in PDL cells and gingival tissue samples were evaluated by real-time PCR. Proliferative responses and mineralized-matrix forming activities of PDL cells were examined in the presence and absence of IL-22.

RESULTS

In contrast to the expression of IL-22 receptors detected in PDL tissues and their cell lines, gingival tissues showed modest or no gene expressions of IL-22. The production of several cytokines including IL-11, IL-8 and CCL2 was upregulated by IL-22 treatment of PDL cells in a dose-dependent manner. IL-22 treatment had no effect on the proliferative response in PDL cells. Meanwhile, IL-22 precipitated mineralized nodule formation and induced gene expressions of RUNX2, MSX2 and osteocalcin in PDL cells, suggesting that IL-22 enhances the mineralized matrix-forming activities of PDL cells.

CONCLUSION

IL-22 has the potential to promote mineralizing activity in PDL cells and to develop appropriate regenerative therapy.

[Massive hemoptysis after lobectomy for bronchiectasis]

A 67-years-old female, who was suffered from hemoptysis for about 50 years and was diagnosed as bronchiectasis of left lower lobe, was admitted to our hospital to receive elective surgical treatment. Left lower lobectomy was performed, and on the 10th postoperative day, massive hemoptysis occurred and intratracheal hemorrhage caused occlusion of the respiratory tract. Selective bronchial arteriogram revealed that bronchial artery of the left upper lobe developed remarkably, compared with the findings 1 year ago, and the bleeding site was located in the left upper lobe, which seemed to be almost normal before the operation. After embolization of this artery the hemoptysis stopped. If bronchial artery, which develop well and distribute to the bleeding lobe of the lung, have branches to adjacent another lobe, change of blood stream of bronchial artery by operation may cause early postoperative recurrence of hemoptysis.

[Ganglioneuroma derived from inferior trunk of the brachial plexus and first intercostal nerve]

A 62-years-old Japanese male, who had mediastinal tumor at the left thoracic inlet, was admitted to our hospital to receive surgical treatment. The tumor behind the left subclavian artery was guessed to be neurogenic benign tumor, though the involvement of the brachial plexus was unclear. We approached the tumor by means of left hemi-collar skin incision, resulting in performing safe operation with directly looking at the tumor that communicated with 1st intercostal nerve and inferior trunk of the left brachial plexus. Pathological diagnosis of the resected tumor was ganglioneuroma. Cervical approach by means of hemi-collar skin incision is thought to be available for surgical treatment of tumors at the thoracic inlet because of easy accessibility and less invasiveness than other approach with dividing bones, such as clavicle, sternum, or ribs.

90-Day repeated-dose toxicity study of licorice flavonoid oil (LFO) in rats

Licorice flavonoid oil (LFO) is a new functional food ingredient consisting of licorice hydrophobic polyphenols in medium-chain triglycerides (MCT). As part of a safety evaluation, a 90-day oral toxicity study in rats was conducted using an LFO concentrate solution (2.90% glabridin). Male and female animals were assigned to one of 12 groups (10 males or females per group) and received corn oil (negative control), MCT (vehicle control), or 400, 600, 800 or 1600 mg/kg of the LFO concentrate solution. In conclusion, LFO concentrate solution induced an anticoagulation effect in both sexes, although there was a clear sex difference. Based on these findings, it is concluded that the no-observed-adverse-effect level (NOAEL) for the LFO concentrate solution is estimated to be 800 mg/kg/day for female rats, and approximately 400 mg/kg/day for male rats.

Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

An atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs). Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

[Yolk sac tumor of the anterior mediastinum and pulmonary metastases; report of a case]

A 31-year-old female was clinically diagnosed as having a anterior mediastinal yolk sac tumor because of the elevation of the AFP (17,500 ng/ml), a large mass lesion (9 x 5 cm) in the anterior mediastinum and bilateral lung metastases. After 4 courses of chemotherapy with cisplatin (CDDP), etoposide (VP-16) and bleomycin hydrochloride (BLM), the mediastinal mass reduced in size significantly and the serum AFP level reached within normal range. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed a weak uptake in the mediastinum, accordingly the operation was performed. The tumor was completely removed and there were no viable foci of the tumor in part of the tumor. After the operation, 4 courses of chemotherapy with carboplatin (CBDCA), VP-16 and ifosfamide (IFM) were performed. She is alive without evidence of recurrence in 5 months after operation. It was noticed that the serum AFP is a useful indicator for determing the chance of operation after chemotherapy.

Thirteen-week feeding study of thaumatin (a natural proteinaceous sweetener), sterilized by electron beam irradiation, in Sprague–Dawley rats

This study was designed to evaluate and characterize any subchronic toxicity of thaumatin sterilized by electron beam irradiation (5.0 kGy) when administered at dietary levels of 0% (control), 0.3%, 1.0% and 3.0% to groups of 10 male and 10 female Crj: CD (SD) IGS rats for 13 weeks. Separate groups of both sexes received 3.0% non-irradiated thaumatin. There were no treatment-related clinical signs or adverse effects on the survival rate, body weight, food consumption, water consumption and urinalysis, ophthalmology, haematology, or blood biochemistry data. No treatment-related alterations in gross pathology or organ weights were found in any group. On histopathological examination, sporadic spontaneous lesions known to occur in this strain of rats were the only findings, with no specific relation to the test substance. Thus, the no-observed-adverse-effect-level (NOAEL) was judged to be a dietary level of at least 3.0% (2502 mg/kg body weight/day for males, 2889 mg/kg body weight/day for females) for electron beam irradiated thaumatin under the present experimental conditions. It was concluded that electron beam-irradiation of thaumatin does not cause changes of any toxicological significance.

28-Day repeated dose toxicity study of dried microorganism in rats

Ubidecarenone, also known as CoQ(10), is currently sold as a dietary supplement in the United States, with a majority of these products derived from the fermentation of carbohydrates or tobacco leaf extracts. In addition to its availability in dietary supplements, CoQ(10) is now being considered for use in foods. Accordingly, as part of the process for attaining "Generally Recognized as Safe" status, and to supplement information already available regarding the safety of CoQ(10) per se, a 28-day oral toxicity study in rats was conducted to evaluate the subacute safety of a microorganism biomass used as a new source in CoQ(10) production. Groups of Crj:CD(SD) rats (SPF) (6 males or females per group, 4 groups per sex) received dried microorganism at doses of 0, 500, 1000 or 2000 mg/kg/day via intragastric intubation. Clinical observations were recorded, and body weight, and food and water consumptions measured throughout the study. At the end of the study, aortic blood samples were collected from all animals for analysis of hematological and clinical chemistry parameters, and gross pathologic examination was performed. Histopathologic examination was performed on select tissues from the control and high-dose groups. There were no treatment-related changes that were considered to be of toxicological significance. Since rats treated with 2000 mg/kg of dried microorganism did not demonstrate any treatment-related changes, the no-observable-adverse-effect level (NOAEL) for dried microorganism was estimated to be greater than 2000 mg/kg/day under the present study conditions.

Oesophageal hypersensitivity in Japanese patients with non-erosive gastro-oesophageal reflux diseases

BACKGROUND

Visceral hypersensitivity plays a major role in the pathogenesis of non-erosive oesophageal reflux disease (NERD). Prevalence of NERD differs according to the population and geographical region. Oesophageal hypersensitivity in NERD has not been well studied, especially in Japanese patients.

AIM

To investigate oesophageal hypersensitivity in Japanese NERD patients.

PATIENTS AND METHODS

We performed upper GI endoscopy and the modified acid perfusion test on 14 control subjects and 68 GERD patients, including 26 with NERD, 34 with erosive GERD, and six with Barrett's oesophagus. The stimulus-response function to acid was quantified by three parameters (lag time, intensity rating and the acid perfusion sensory score) and compared among four groups.

RESULTS

The mean value of the lag time, intensity rating, and acid perfusion scores in NERD patients (4.6 +/- 3.4, 4.4 +/- 3.4, 27.8 +/- 26.7, respectively) were higher than in erosive GERD (3.2 +/- 3.3, 3.0 +/- 3.2, 18.2 +/- 24.8) and Barrett patients (2.5 +/- 4.0, 1.8 +/- 3.3, 15.0 +/- 28.8), and significantly higher than in the control group (1.7 +/- 2.7, 1.1 +/- 2.0, 5.4 +/- 11.8). The ratio of patients with higher sensory scores was also greater in the NERD group (57.7%) than in erosive GERD (32.3%) and Barrett group (16.7%), and significantly greater than in control group (6.7%).

CONCLUSION

Our findings suggest that oesophageal sensitivity is likely to be enhanced especially in NERD patients also in Japanese population in comparison with erosive GERD, Barrett's oesophagus and controls.

Review of combination of peritoneal dialysis and hemodialysis as a modality of treatment for end-stage renal disease

Because the contribution of residual renal function (RRF) to total solute clearance is often significant in continuous ambulatory peritoneal dialysis (CAPD), loss of RRF over time can lead to inadequate dialysis if appropriate prescription management strategies are not pursued. Additionally, declines in ultrafiltration caused by increases in peritoneal permeability may limit continuation of CAPD therapy. Peritoneal dialysis and hemodialysis (PD + HD) combination therapy (complementary dialysis therapy) is an alternative method. This therapy allows the patient to maintain daily activities, as with CAPD, while undergoing once-a-week HD supplements for the insufficient removal of solutes and water. This therapy allows for the continuation of PD without shifting to total HD in PD patients who continue to have uremic symptoms even after individualization of the PD prescription. This treatment option is psychologically more acceptable to patients and may be expected to provide such accompanying beneficial effects as peritoneal resting, improvement of QOL and reduction in medical cost.

Western blotting analysis of the beta-hexosaminidase alpha- and beta-subunits in cultured fibroblasts from cases of various forms of GM2 gangliosidosis

OBJECTIVES

The GM2 gangliosidoses are a group of genetic disorders caused by the accumulation of ganglioside GM2 in neuronal cells. We examined the alpha- and beta-subunits of beta-hexosaminidases by a non-radioisotopes detecting system to evaluate whether it was a useful method for understanding of the pathophysiologies of GM2 gangliosidoses.

MATERIALS AND METHODS

We investigated the alpha- and beta-subunits of beta-hexosaminidases in cultured fibroblasts from cases of various forms of GM2 gangliosidosis by means of Western blotting and a chemiluminescence detection system.

RESULTS

In a patient with infantile Tay-Sachs disease [HEXA genotype, Int5-SA(g-1-->t)/Int5-SA(g-1-->t)], the mature alpha-subunit was undetectable. In a patient with infantile Sandhoff disease (HEXB genotype, C534Y/C534Y), the mature beta-subunit was deficient. However, a small amount of the mature beta-subunit was detected in a patient with adult Sandhoff disease (HEXB genotype, R505Q(+I207V)/R505Q(+I207V)), which may have resulted in the residual enzyme activity and mild clinical course. Normal amounts of alpha- and beta-subunits were detected in a patient with GM2 activator deficiency.

CONCLUSION

This method is easy and sensitive for detecting target proteins, and is useful for clarification of the pathophysiologies of GM2 gangliosidoses.

Modifying effects of propolis on MeIQx promotion of rat hepatocarcinogenesis and in a female rat two-stage carcinogenesis model after multiple carcinogen initiation

The modifying effects of the dietary administration of water- and ethanol-extracted propolis produced in Brazil (WB and EB, respectively) on 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) promotion of rat hepatocarcinogenesis were investigated in a medium-term liver bioassay system with use of male Fischer 344 rats. The number and area of glutathione S-transferase placental form (GST-P)-positive foci in rats given 0.5% WB were significantly increased compared with the group given MeIQx alone. Furthermore, the numbers of GST-P-positive foci were higher in rats given 0.1% WB or EB than in those given the basal diet alone. The modifying effects of propolis on other organs were also examined in female Fischer 344 rats given multiple carcinogens for initiation. Rats received water- and ethanol-extracted propolis produced in Brazil and Uruguay (WB, EB, WU, and EU, respectively) in the diet after exposure to three different carcinogens. The incidence of total mammary tumors was significantly lower in rats given EU than in the control group. These results indicate that a water extract of propolis exerts a cocarcinogenic effect on MeIQx hepatocarcinogenesis while promoting the effect at low dose in a two-stage hepatocarcinogenesis model. Moreover, they suggest that ethanol-extracted propolis may be an inhibitor of mammary gland carcinogenesis.

Epoprostenol sodium, a prostaglandin I2, lacks tumor promoting effects in a medium-term liver carcinogenesis bioassay in rats

Potential modifying effects of epoprostenol sodium administration on liver carcinogenesis were investigated in male F344/DuCrj rats initially treated with N-nitrosodiethylamine (DEN). Two weeks after a single dose of DEN (200 mg/kg, intraperitoneally), rats daily received subcutaneously epoprostenol sodium at doses of 0, 1, 10 and 100 microg/kg, or were fed phenobarbital sodium (PB) at a dietary level of 500 parts per million (ppm) as positive control for 6 weeks. All animals were subjected to partial hepatectomy at week 3, and were killed at week 8. Prominent flushing of extremis and signs of behavioural depression occurred after injection and lasted for 1 h in rats given 100 microg/kg epoprostenol sodium. Such clinical signs were slight in rats treated with 10 microg/kg, but not observed with 1 microg/kg. Marked decrease in body weight gain was noted in rats given 100 microg/kg. Statistically significant changes in relative liver weights were not found in any group given the test chemical. Epoprostenol sodium did not significantly increase the quantitative values for glutathione S-transferase placental form (GST-P) positive liver cell foci observed after DEN initiation, in clear contrast to the positive control. The results thus demonstrate that epoprostenol sodium lacks modifying potential for liver carcinogenesis in our medium-term bioassay system.

The incidence of reflux oesophagitis after cure of Helicobacter pylori in a Japanese population

AIM

To investigate the incidence of reflux oesophagitis after antibacterial therapy for Helicobacter pylori infection in our patient population.

METHODS

Subjects were 451 H. pylori-infected patients (primary symptom: peptic ulcer disease in 347, nonulcer dyspepsia in 100, and reflux oesophagitis in four): 11 of these patients had reflux oesophagitis on study entry. H. pylori infection was treated by a proton pump inhibitor/amoxycillin-clarithromycin regimen for either 7 or 14 days. Each patient was examined by endoscopy before treatment and more than 6 months after treatment to compare oesophageal findings. In addition, 227 patients were interviewed regarding reflux symptoms, using symptom questionnaires, before and more than 6 months after treatment.

RESULTS

Among 440 patients who did not have reflux oesophagitis prior to antibacterial treatment (340 peptic ulcer patients and 100 nonulcer dyspepsia patients), 23 patients whose infection was eradicated developed reflux oesophagitis (5.4%). The 11 patients who had reflux oesophagitis prior to treatment were all successfully cured of infection. Six of these patients showed no change in their oesophagitis, while the condition improved in three and worsened in two. Symptom scores improved in 34 of the 36 patients who reported reflux symptoms. Among 19 patients who showed persistent infection, only one developed reflux oesophagitis (5.2%), while none complained of newly developed symptoms following treatment.

CONCLUSIONS

Development of reflux oesophagitis after treatment of H. pylori infection was observed in a Japanese population. However, the incidence of this condition was comparable between those with persistent H. pylori infection and those in whom the infection was eradicated.

Post-initiation effects of a super critical extract of propolis in a rat two-stage carcinogenesis model in female F344 rats

Post-initiation modifying effects of dietary administration of a super critical extract of propolis on major organs were examined using a two-stage carcinogenesis model. Groups of 21 or 22 F344 female rats were treated sequentially with 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN, i.g.), 7,12-dimethylbenz[a]anthracene (DMBA, i.g.), 1,2-dimethylhydrazine (DMH, s.c.) and N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN, in drinking water) during the first 3 weeks for initiation, and then administered diet containing 0.1 or 0.01% propolis for 33 weeks. Further groups were treated with the carcinogens alone, 0.1% propolis alone or basal diet alone. All surviving animals were killed at week 36, and major organs were examined histopathologically for development of preneoplastic and neoplastic lesions. The incidence and multiplicity of mammary carcinomas were significantly decreased by the 0.1 and 0.01% propolis treatments. In the urinary bladder, the incidence of PN hyperplasia but not tumors was, in contrast, significantly increased by 0.1% propolis. Similarly, the number and area of glutathione S-transferase placental form (GST-P)-positive liver foci were significantly elevated with this high dose. The results indicate that a low dose of a super critical extract of propolis may find application as a potent chemopreventor of mammary carcinogenesis.

CYP1A2 is not the primary enzyme responsible for 4-aminobiphenyl-induced hepatocarcinogenesis in mice

4-Aminobiphenyl (4-ABP), a potent carcinogen in rodents (liver cancer) and human (bladder cancer), is found as an environmental contaminant and in tobacco smoke. Hemoglobin adducts and lung DNA adducts of 4-ABP are found in tobacco smokers. In vitro metabolism studies with human and rat liver microsomes have shown that CYP1A2 is primarily responsible for catalyzing N-hydroxylation, the initial step in the metabolic activation of 4-ABP. To determine whether this P450 is a rate limiting pathway for hepatocarcinogenesis, CYP1A2-null mice were analyzed at 16 months of age and were compared with wild-type mice in their response to 4-ABP using the neonatal mouse bioassay and two different doses of the carcinogen. Overall differences in incidences of hepatocellular adenoma, carcinoma and preneoplastic foci were not significant between either genotypes or 4-ABP doses used, whereas small, but significant, differences were found for specific types of foci. These results suggest that while CYP1A2 levels may not be rate limiting for 4-ABP metabolism to produce tumors and foci, it may modulate the induction process of some types of liver foci in either a positive or negative manner. In vitro studies using CYP1A2-null and wild-type mouse liver microsomes revealed that CYP1A2 is not the sole P450 required for 4-ABP N-hydroxylation and that another, yet to be identified, P450 is likely to be involved.

Organ-dependent modifying effects of caffeine, and two naturally occurring antioxidants alpha-tocopherol and n-tritriacontane-16,18-dione, on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary and colonic carcinogenesis in female F344 rats

Modifying effects of caffeine, alpha-tocopherol, and n-tritriacontane-16,18-dione (TTAD) on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary and colonic carcinogenesis were investigated in female F344 rats. Groups of 20 rats, 6 weeks old, were given 0.02% PhIP (in diet) alone, or together with 0.1% caffeine (in drinking water), 0.5% alpha-tocopherol (in diet) or 0.1% TTAD (in diet) for up to 54 weeks. Groups of 10 females receiving basal diet or one of the test chemicals without PhIP supplementation were also maintained. The final combined incidences (adenomas plus adenocarcinomas) and multiplicity (No./rat) of mammary adenomas and adenocarcinomas were significantly lowered in the PhIP plus caffeine group (10%, 0.10) as compared to the PhIP alone value (40%, (1.50). Incidences of mammary tumors in the PhIP plus alpha-tocopherol or TTAD groups tended to be decreased while their multiplicities were significantly lowered. With regard to colon tumor development, on the other hand, rats given PhIP plus caffeine exhibited an elevated incidence (75% versus 15% in the control), whereas alpha-tocopherol and TTAD had no effect. Surprisingly, metabolic activation of PhIP was inhibited by addition of caffeine in an in vitro assay. The results indicate that caffeine exerts a potent chemopreventive action against PhIP-induced mammary carcinogenesis, but acts as a co-carcinogen for PhIP-induced colonic carcinogenesis.

Relapsed duodenal ulcer after cure of Helicobacter pylori infection

We report a patient--a 42-year-old man--who had suffered from recurrent duodenal ulcer for about 20 years. Successful curative therapy for Helicobacter pylori infection was performed for 2 weeks with new triple omeprazole, anoxicillin, clarithromycin (OAC) treatment in October 1995, and cure of the infection was repeatedly confirmed by histology, culture, and the 13C urea breath test. One month after the curative therapy, recurrence of a small duodenal ulcer was observed and in February another duodenal ulcer and reflux esophagitis occurred, with severe symptoms, despite the continuous administration of ranitidine. None of the examinations to reconfirm cure of the infection revealed the presence of H. pylori. As the patient experienced continual psychological stress and smoked more frequently during the recurrent episode and had not used nonsteroidal anti-inflammatory drugs, stress and smoking appeared to play important roles in the relapse of duodenal ulcer in this patient after cure of H. pylori infection.

Post-initiation inhibitory effects of green tea catechins on 7,12-dimethylbenz[a]anthracene-induced mammary gland carcinogenesis in female Sprague-Dawley rats

The dose-dependence of green tea catechin (GTC) effects on 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary gland carcinogenesis were investigated in female Sprague-Dawley rats. Groups of 20 6-week-old rats were treated with dietary 1, 0.1 or 0.01% GTC for 2 weeks and then basal diet alone for 35 weeks. At the end of week 1, they received a 25 mg/kg body weight intragastric dose of DMBA. Further groups of 20 7-week-old rats each were given an intragastric dose of 25 mg/kg body weight DMBA, and starting 1 week after DMBA treatment they were placed on diet containing 1, 0.1 or 0.01% GTC or basal diet alone for 35 weeks. Control rats were given 1% GTC or basal diet alone. The final incidences and multiplicities of mammary tumors were not significantly different between the groups treated with GTC at the same time as DMBA, compared to the DMBA alone control group. On the other hand, the final multiplicities of mammary tumors in groups treated with 1% GTC (P < 0.05) or 0.01% GTC (P < 0.01), but not 0.1% GTC, after DMBA treatment were significantly decreased as compared to the control value. These results indicate that whereas GTC may inhibit mammary carcinogenesis in the post-initiation stage, the effect is weak and not dose-dependent.

Effect of fasting subjects' posture on 13C-urea breath test for detection of Helicobacter pylori infection

BACKGROUND

Although many factors that may affect the 13C-urea value have been verified, no literature is available regarding the effect of the posture of the patient on the shape of the delta 13C excretion curve. In an effort to contribute to the development of a simple and standard procedure for the 13C-urea breath test, we investigated whether either the posture of the patient during the procedure or the mouthwash after dosing affects the shape of the delta 13C excretion curve.

MATERIALS AND METHODS

Seventy-two Helicobacter pylori-infected subjects were divided into four groups according to the position during procedure and the mouthwash after dosing: group A, in the supine position with mouthwash; group B, in the sitting position with mouthwash; group C, changed position by rolling with mouthwash; and group D, changed position (as did group C) without mouthwash. Absolute values of delta 13C at each sampling point were compared in the four groups.

RESULTS

delta 13C values in group A gradually increased until the 15-minute point; those in group B were almost stable from 5 to 30 minutes, and those in group C peaked at the 5-minute point, then decreased until 30 minutes, the values becoming similar at the 20-minute point. Significant differences were seen between groups A, B, C, and D at the 5- and 10-minute points.

CONCLUSION

These results suggest that posture and mouthwash affect delta 13C value at the 5- and 10-minute points. Sampling at 20 (maybe 15 or 30) minutes for fasting patients in a sitting position is considered to be appropriate for detection of H. pylori infection in a standard two-sampling-point 13C-urea breath test.

Lack of involvement of p53 gene mutations in N-methyl-N-nitrosourea-induced bladder tumor progression in N-butyl-N-(4-hydroxybutyl)nitrosamine-treated rats and no suppression by indomethacin

The relevance of p53 mutations to rat bladder cancer progression induced by a single injection of N-methyl-N-nitrosourea (MNU) and the chemopreventive effects of indomethacin (IM) were investigated in male F344 rats, initially given N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) at a dose of 500 ppm in the drinking water for 10 weeks. The animals were subsequently treated with a single intraperitoneal injection of MNU at a dose of 50 mg/kg b.w. at week 20. A subgroup was then given IM dissolved in the drinking water at a concentration of 20 ppm for 20 weeks. The experiment was terminated at week 40 when transitional cell carcinomas (TCC) were observed in all animals given BBN, regardless of the administration of MNU and/or IM (incidences ranged from 80 to 100%). The extent of invasion was significantly greater with the additional MNU treatment but no inhibitory effects of IM were noted. A low frequency of p53 mutations was detected without relation to the extent of tumor invasion. Thus, only two mutations were found, one in a Ta and the other in a T1 carcinoma. The present study thus demonstrated that p53 mutations are not involved in MNU-induced progression in rat urinary bladder cancers, suggesting that they are not critical for malignancy.