Dose-responsive alteration in hepatic lipid peroxidation and retinol metabolism with increasing dietary beta-carotene in iron deficient rats

Phosphatidylcholine hydroperoxide (PCOOH) levels are increased in the iron-deficient rat liver. We investigated the antioxidative effect of dietary beta-carotene and altered retinol metabolism in iron-deficient rats. Experiment 1: Male Wistar-strain rats were divided into six groups and fed a control diet, an iron-deficient diet, and iron-deficient diets with four different levels of dietary beta-carotene. The PCOOH concentration in the iron-deficient rat liver was decreased by supplementation with dietary beta-carotene. However, the beta-carotene dose response was not related to antioxidative potency. Hepatic and plasma beta-carotene concentrations were increased by iron deficiency. The hepatic retinol concentration was increased while the plasma retinol concentration was decreased in iron-deficient rats. Experiment 2: Male Wistar-strain rats were divided into two groups, with one group receiving a control diet with beta-carotene and the other an iron-deficient diet with beta-carotene. Intestinal iron was decreased and intestinal beta-carotene was unchanged in iron-deficient rats. The intestinal beta-carotene conversion ratio and beta-carotene cleavage enzyme activity were decreased in iron-deficient rats. Dietary beta-carotene played the role of an antioxidant in hepatic lipid peroxidation in the iron-deficient state, but there was no dose dependency. Moreover, intestinal beta-carotene cleavage and hepatic retinol release appear to be altered in iron-deficient rats.     

Detection of mycobacterium bovis BCG Tokyo in sputum from a tuberculosis patient and administrative action in public health

PURPOSE: We encountered a tuberculosis patient with the BCG strain in his sputum. Based on this experience, we investigated ideal surveillance and quality assurance for bacteriological examination as well as cooperation between medical organizations and public administrative organizations such as public health centers for prompt and appropriate measures against tuberculosis. METHODS: Acid-fast bacilli isolated in the laboratory of a hospital were analyzed by restriction fragment length polymorphism (RFLP) and molecular epidemiological data for pathogen were provided to the public health center in charge. RESULTS: DNA of acid-fast bacilli isolated from sputum of a tuberculosis patient showed a BCG like pattern on RFLP analysis using two IS6110 and PGRS (polymorphic GC-rich sequence) probes. Additional investigation revealed that the patient had been treated with BCG immuno-therapy against bladder cancer. Accordingly, it was suggested that this was the origin of the BCG strain in the sputum. Therefore, the patient was re-examined clinically, and further contact tracing by the public health center was stopped. CONCLUSIONS: This study indicates that adequate surveillance and quality assurance in bacteriological examination as well as effective exchange of information between medical organization and public health centers are very important for prompt and appropriate measures against tuberculosis. Further, it provided strong support for identification of pathogens of the molecular level by RFLP analysis.     

Post launch studies

Evidence Based Medicine (EBM) is a growing concept in Japan as it is elsewhere. Central to improving the use of EBM is generation of data through well conducted controlled clinical studies. There are many problems associated with conduct of clinical studies after launch in Japan, and many initiatives are ongoing to improve the situation. Development of Clinical Research Coordinators (CRO) and central Data Management centers are key to improving the quality of clinical research in Japan. Currently Japan has an undeveloped legal system with regard to post-launch trials and off-label use of registered drugs. There is no reimbursement for off-label and various restrictions imposed on the recipients of the Ministry of Health, Labour and Welfare's (MHLW) funds. Maybe the biggest problem is the high cost of post-marketing studies sponsored by pharmaceutical manufacturers. A high quality system to support post launch clinical studies need a solid financial base. There is a need for a suitable review system for investigator initiated multi-centre studies, as the current IRB system is not sufficient. There are also challenges regarding the differences, perceived or real, in treatment practice and available registrations in Japan and in the West, causing problems in choosing suitable comparators and study designs. At the present time it is not clear whether investigator initiated trials will be acceptable for registration purposes in Japan. The agreed first priority is to build a suitable and strong infrastructure within the academic community to support researchers to investigate important questions with or without pharmaceutical company support. Despite all these issues, several groundbreaking projects are under way throughout Japan, in many different areas and by different collaborative groups, some with government support. In fact, researcher-initiated clinical trials achieved a rapid growth in Japan in the past year.     

A new LH-RH agonist for treatment of prostate cancer, 3-month controlled-release formulation of goserelin acetate (Zoladex LA 10.8 mg depot)--outline of pre-clinical and clinical studies

Goserelin acetate is a LH-RH agonist developed by AstraZeneca (formerly ICI, UK), and has been used clinically for the treatment of prostate cancer as a 4-week controlled-release formulation (Zoladex 3.6 mg depot). Recently, a new drug (Zoladex LA 10.8 mg depot) with 3-month controlled-release formulation was developed and became commercially available in Japan. In the randomized comparative phase III studies carried out with global bases, single administration of the new drug yielded almost equivalent anti-testosterone effect and the same serum level of the previous 3.6 mg depot formulation in 3-times continuous administration. In these studies, adverse drug reactions, which were mainly due to pharmacological effects of the new drug and minimal, were found in 52.6% (41/78) compared with 54.8% (46/84) with the previous 3.6 mg depot formulation. In the phase III studies, there were no significant differences in average serum testosterone levels between the two formulations at 12 and 13 weeks after administration. In the Japanese late phase II study with untreated patients, castration effect was observed in all 20 cases entered in the trial. In 20 cases in which treatment was switched from 3.6 mg depot to the new formulation, there were no significant changes in serum testosterone levels at castration level of the untreated patients, 90% (18/20) responded to the treatment, and normalization of PSA level was found in 75.0% (15/20). The adverse drug reactions were mainly increased triglyceride level and hot flushes. In the retrospective evaluation of untreated patients in this trial and the post-marketing clinical trial data for 3.6 mg depot, it was concluded that the new drug had almost the same efficacy and safety profile as 3.6 mg depot in Japanese people. These results indicate that Zoladex LA 10.8 mg depot has the same efficacy and safety as 3.6 mg depot with administration every three months, the burden of injection of LH-RH agonist can be reduced. This new medication can be considered a new standard for treatment of prostate cancer.     

Minimally invasive endoscope-assisted endonasal trans-sphenoidal microsurgery for pituitary tumors: experience with 215 cases comparing with sublabial trans-sphenoidal approach

Recent advances in endoscopic surgery have developed an endonasal route suitable for pituitary surgery. The main goal of this article is to evaluate benefits of our endoscope-assisted endonasal trans-sphenoidal microsurgery for pituitary tumors in 215 consecutive cases. The pathological classifications of the 215 cases are as follows: 163 pituitary adenomas, 23 Rathke's cleft cysts, 17 craniopharyngiomas, and 12 others. The patients were surgically treated via the endonasal trans-sphenoidal approach using an operating microscope as the primary instrument for tumor resection. Endoscopes were used to complement the operating microscope in visualization. We compared the new approach to the sublabial trans-sphenoidal approach (197 cases) with respect to endocrinological outcomes and surgical complications. Our endonasal trans-sphenoidal approach was beneficial in eliminating the complications of lip numbness, which was often observed in patients undergoing sublabial surgery, and nasal septal perforation. In addition, endocrinological outcome comparable to those in the sublabial group was achieved in the endonasal group. We consider that the endoscope, which allows visualization of areas not seen with the operating microscope, should be used actively in conjunction with the operating microscope that provides three-dimensional visualization and is timesaving. Our surgical method for pituitary tumors provides good results with minimal invasion, by exploiting the advantages of a microscope and an endoscope.     

Oxidative ability and toxicity of n-hexane insoluble fraction of diesel exhaust particles.

Diesel exhaust particles (DEP) are known to induce adverse biological responses such as inflammation of the airway. However, the relationship between the chemical characteristics of organic compounds adsorbed on DEP and their biological effects is not yet fully understood. In this study, the dichloromethane-soluble fraction (DMSF) from DEP was fractionated into its n-hexane-soluble fraction (n-HSF) and n-hexane-insoluble fraction (n-HISF). Using these DEP fractions, we designed the present studies to elucidate (1) chemical characteristics, (2) biological characteristics, and (3) the relationship between the chemical and the biological characteristics of these DEP fractions. Dithiothreitol (DTT) assay, Fourier transform-infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) were used to characterize their chemical properties. Heme oxygenase-1 (HO-1) protein expression, viability of rat alveolar type II epithelial cell line (SV40T2), and inflammatory cell infiltration into the peritoneal cavity of BALB/c mice were evaluated as markers of oxidative stress, cytotoxicity, and inflammatory response, respectively. The oxidative ability of the DEP fractions was n-HISF > DMSF > n-HSF. IR, 1H-NMR, and GC-MS spectra showed that n-HISF was mainly composed of compounds having many functional groups related to oxygenation, such as hydroxyl and carbonyl groups. The relative strength of HO-1 protein expression, cytotoxicity, and inflammatory responses was also n-HISF > DMSF > n-HSF. All of the n-HISF-induced biological activities were decreased by reduction with N-acetyl-L-cysteine (NAC). These results suggest that n-HISF has high oxidative ability and many functional groups related to oxygenation and that this ability strongly contributes to the induction of oxidative stress, cytotoxicity, and inflammatory response.     

Hedgehog: an attribute to tumor regrowth after chemoradiotherapy and a target to improve radiation response.

PURPOSE: Despite aggressive chemotherapy, radiotherapy, surgery, or combination approaches, the survival rate of patients with esophageal cancer remains poor. Recent studies have suggested that constitutive activation of the Hedgehog (Hh) pathway in cancers of the digestive tract may contribute to the growth and maintenance of cancer. However, the relationship between Hh signaling and therapeutic response is unknown. EXPERIMENTAL DESIGN: The expression and temporal kinetics of Hh signaling and proliferation biomarkers after chemoradiotherapy were examined in esophageal tumor xenografts. Additionally, immunohistochemical analysis of Sonic Hh (Shh) and Gli-1 expression were done on residual tumors from patients who received neoadjuvant chemoradiotherapy followed by surgery. The ability of Shh signaling to induce proliferation in esophageal cell lines was determined. Expression of cell cycle checkpoint proteins was analyzed in cells in which Hh signaling was activated or inhibited. We further determined the effect of inhibiting Hh signaling in sensitizing esophageal tumors to radiation. RESULTS: We showed that the Shh signaling pathway was extensively activated in esophageal cancer xenografts and residual tumors after chemoradiotherapy and the temporal kinetics of Hh signaling preceded increases in proliferation biomarker expression and tumor size during tumor regrowth. We further showed that Hh pathway activity influences proliferation rates of esophageal cancer cell lines through up-regulation of the G1-cyclin-Rb axis. Additionally, we found that blocking Hh signaling enhanced radiation cytotoxicity of esophageal cancer cells. CONCLUSIONS: These results suggest that activation of the Hh pathway may promote tumor repopulation after chemoradiotherapy and contribute to chemoradiation resistance in esophageal cancers.