A novel combretastatin A-4 derivative, AC7700, which is now in Phase I clinical trials under a new code, AVE8062, has shown strong antitumour effects against solid tumours in rodents because of its powerful and continued stanching of the tumour blood flow (TBF). Despite the strong tumour-suppressing qualities of AC7700, it does not produce an immediate reduction in tumour size. To elucidate the reason for this effect, we investigated the relationship between the change in tumour size in Sato lung carcinoma (SLC) and circulatory functions after therapy with AC7700, doxorubicin (Adriamycin [ADR]), or mitomycin C (MMC). To measure time-lapse changes in TBF with the hydrogen clearance method at the same site after drug administration, we developed a new apparatus for keeping electrodes within a tumour. AC7700 led to the destruction of both cancer cells and tumour vessels by interrupting the supply of nutrients. Intravenous (i.v.) administration of fluorescent dyes after AC7700 treatment revealed no fluorescence within the tumour vessels, which confirmed that the tumour microcirculation had been completely blocked. In contrast, ADR led to the destruction of SLC tumour cells, but did not have the same effect on tumour vessels. Intravenously administered fluorescent dyes immediately reached the tumour, which indicated that the tumour vasculature remained intact, and the TBF remained at the preadministration level, even 6 days after ADR treatment. In addition, although the size of the tumour increased slightly for 2 days with ADR treatment, possibly because of swelling of the cancer cells, thereafter it continued to decrease. MMC had virtually no effect on SLC tumour cells, tumour size or tumour vessels. We conclude that changes in tumour size brought about by cancer chemotherapy depend not only on the sensitivity of the cancer cells to the drug in question, but also on the nature of changes in the microcirculatory functions of the tumour brought about by the therapy. When both tumour cells and the tumour vasculature are destroyed, the effectiveness of therapy can not be determined from changes in tumour size alone.

Animals↗

PubMed2003

Relation between voluntary physical activity and oxidant/antioxidant status in rats.

The relationship between voluntary distance running and antioxidant capacity was studied in rats after three weeks voluntary running. Hydroxyl radical level, reduced glutathione level, activities of glutathione reductase and superoxide dismutase were measured in plasma, liver, brain, soleus and gastrocnemius white muscle. Hydroxyl radical level of liver negatively correlated with the running distance (r=-0.616, P<0.001). The reduced glutathione levels of liver and brain increased depending on the running distance and the correlation was confirmed between them in liver (r=0.638, P<0.01) and brain (r=0.766, P<0.001). The hydroxyl radical level in liver positively correlated with the activities of glutathione reductase (r=0.464, P<0.05) and superoxide dismutase (r=0.549, P<0.05). A significant positive correlation was detected between the hydroxyl radical level and superoxide dismutase activity in brain (r=0.488, P<0.05). These results demonstrate that physical activity correlates well with glutathione level and anti-oxidant enzyme activities in liver, suggesting a close relation between physical activity and induction of antioxidant systems.

Animals↗

PubMed2003

RETRACTED: Comparative effects of vitamin K and vitamin D supplementation on prevention of osteopenia in calcium-deficient young rats.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The Journal has been made aware of concerns regarding the integrity of the data, authorship and ethical approval for this study. Despite repeated attempts to contact the co-authors we have been unable to confirm the authorship of this paper.

Animals↗

PubMed2003

Classification of oral streptococci by two-dimensional gel electrophoresis with direct activity stain for glycosyltransferases.

Thirty eight strains of oral streptococci were divided into six types by two-dimensional gel electrophoresis (2-DE) followed by glycosyltransferase (GLT) activity stain: Type 1, Streptococcus mutans; Type 2, Streptococcus rattus; Type 3, Streptococcus sobrinus and Streptococcus downei; Type 4, Streptococcus cricetus; Type 5, Streptococcus salivarius; and Type 6, Streptococcus sanguis, Streptococcus oralis and Streptococcus gordonii. In Types 1, 2 and 5, two glucosyltransferases synthesizing water-insoluble (GTF-I) and water-soluble glucans (GTF-S) and a fructosyltransferase (FTF) were detected. In Types 3 and 4, GTF-I and two GTF-Ss were detected. Only one GTF-S was detected in Type 6. The 2-DE patterns for these six types were clearly distinguished from each other based on the kind, number and location of GLTs in gel.

Bacterial Typing Techniques↗

PubMed2003

Relaxing intraoperative natural sound blunts haemodynamic change at the emergence from propofol general anaesthesia and increases the acceptability of anaesthesia to the patient.

BACKGROUND: It is known that auditory input, such as comforting music or sound, blunts the human response to surgical stress in conscious patients under regional anaesthesia. As auditory perception has been demonstrated to remain active under general anaesthesia, playing comforting sounds to patients under general anaesthesia might also modulate the response of these patients to surgical stress. METHODS: Fifty-nine patients scheduled for laparoscopic cholecystectomy were anaesthetized with propofol general anaesthesia in combination with epidural anaesthesia. Natural sounds, chosen preoperatively by each patient as being comforting, were played to 29 patients using headphones during surgery (S group) and the remainder of the patients (n = 30) were fitted with dummy open-type headphones (N group). We compared the haemodynamic change during anaesthesia and the acceptability of anaesthetic practice between the two groups in a randomized double-blind design. RESULTS: There were no differences in haemodynamics between the S and N groups during surgery. During the emergence from anaesthesia, the mean blood pressure and heart rate gradually increased; both parameters were significantly higher in the N group than in the S group. Postoperatively, patients in the S group perceived the experience of anaesthesia as significantly more acceptable than did those in the N group. CONCLUSION: These findings indicate that allowing patients comforting background sounds during general anaesthesia may blunt haemodynamic changes upon emergence from general anaesthesia and increase the acceptability of the experience of anaesthesia.

Aged↗