Sex differences in oxidative damage in ddY mouse kidney treated with a renal carcinogen, iron nitrilotriacetate

Iron-induced free radical injuries in male and female ddY mice, especially the sex difference and its mechanisms, were studied after an i.p. injection of a renal carcinogen, ferric nitrilotriacetate. Male mice were much more susceptible to iron-induced free radical injuries than female mice. Oxidative modification of proteins and DNA occurred more strongly in males than in females, as measured by protein carbonyl content and 8-hydroxydeoxyguanosine, respectively. Histochemical detection of 4-hydroxy-2-nonenal-modified proteins using an antibody and DNA fragmentation as detected by the TUNEL method also showed that males are more severely damaged than females, especially in the proximal convoluted tubules. These results could not be explained by the difference in iron status between male and female mice. In fact, the toxic so-called 'free' iron in serum and kidney were not different between male and female mice and storage iron, such as ferritin and hemosiderin, was also comparable in both kidneys. In previous studies we proposed the glutathione cycling hypothesis to explain the sex differences. The half-life of glutathione in the kidney was significantly shorter in males (29 min) than in females (57 min), as determined by the glutathione decrease after buthionine sulfoximine treatment, a specific inhibitor of glutathione synthesis. The specific activity of gamma-glutamyltranspeptidase (EC 2.3.2.2) in female mice was 73% of that in male mice. These results suggest that the faster glutathione turnover in males could account for the higher susceptibility to oxidative injury by supplying the reducing equivalent that reduces Fe(III) to Fe(II), thereby facilitating iron-catalyzed free radical reactions.

Cupric nitrilotriacetate induces oxidative DNA damage and apoptosis in human leukemia HL-60 cells

Recent reports have implicated a possible role of reactive oxygen species (ROS) in the induction and mediation of apoptosis and DNA damage. Oxidative DNA base modification induced by cupric nitrilotriacetate (Cu-NTA) and the following apoptosis were observed in human promyelocytic leukemia HL-60 cells. We measured the level of ROS in the cells by using a fluorescence probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), and the amount of a modified DNA base, 8-hydroxydeoxyguanosine (8-OHdG) by HPLC-ECD. It was found that Cu-NTA exposure significantly enhanced ROS and 8-OHdG formation in the cells. Meanwhile, we observed both DNA fragmentation and morphological changes characteristic of apoptosis, which was also determined quantitatively by flow cytometry and showed dose- and time-dependent manners. Furthermore, several antioxidants such as dimethyl sulfoxide (DMSO), superoxide dismutase (SOD), and catalase were used to detect whether the apoptosis could be blocked. Only DMSO protected against this form of cell death. To elucidate molecular events in the apoptosis, expressions of Bcl-2 protein family members, such as Bcl-2, Bcl-X and Bax, and heat shock protein 70 (HSP-70) were measured by western blotting using specific antibodies. The levels of Bax and Bcl-Xs remained largely unchanged, but the Bcl-2 and Bcl-XL expression showed down-regulation. After 24 h incubation in the presence of copper, the levels of Bcl-2 and Bcl-XL reduced about 33.8% and 51.1% compared with untreated cells, respectively. Furthermore, after 16 h incubation, the level of HSP-70 expression was about 3.4-fold greater than that in untreated cells, suggesting that HSP-70 is important in increasing resistance to oxidative stress induced by Cu-NTA. But overexpression of HSP-70 failed to protect HL-60 cells from apoptosis induced by Cu-NTA. We inferred that Cu-NTA may induce oxidative DNA damage through free radical injuries, which may turn on the apoptosis in HL-60 cells.

Characterization of a novel human natural killer-cell line (NK-YS) established from natural killer cell lymphoma/leukemia associated with Epstein-Barr virus infection

A novel cell line was established from a patient with a leukemic-state nasal angiocentric natural killer (NK) cell lymphoma with systemic skin infiltration. The morphology of the leukemic cells was large-granular-lymphocyte (LGL), and their immunophenotype was CD2+, CD3-, CD5+, CD7+, CD16-, CD56+, and CD57-. The presence of Epstein-Barr viral (EBV) genome was shown in specimens from the patient's nose, skin, and peripheral blood by in situ hybridization using an EBV-encoded small RNA-1 probe or by Southern blotting using a terminal-repeat probe of the EBV genome. Leukemic cells were cocultured with a mouse stromal cell line (SPY3-2) in the presence of 100 U/mL recombinant human interleukin-2 and a novel stromal cell-independent cell line, NK-YS, was established. The NK-YS cells showed LGL morphology and expressed surface CD2, CD5, CD7, CD25, CD56, and CD95. The NK-YS cells retained cytotoxicity against K562 and Jurkat cells. A Southern blotting using a terminal-repeat probe of EBV showed that NK-YS and fresh leukemic cells had a clonal EBV genome, whereas the T-cell receptor beta and gamma chain genes of NK-YS were not rearranged. In an immunocytochemical analysis, the NK-YS cells showed a type-II latent infection of EBV. The NK-YS cells preserved the original characteristics of NK cell lymphoma/leukemia and will be a useful tool for the study of biological characteristics of EBV-associated nasal angiocentric NK cell lymphoma/leukemia.

Neuropathy associated with angioimmunoblastic lymphadenopathy-like T-cell lymphoma

A 75-year-old woman was admitted because of pain and numbness in the extremities and trunk. She subsequently suffered from lymphadenopathy and spiky fever. The immunohistochemical analysis of the biopsied lymph nodes and sural nerve and electrophysiological examination supported a diagnosis of angioimmunoblastic lymphadenopathy-like T cell lymphoma with polyneuropathy. The infiltrating lymphoma cells of the sural nerve and lymph node shared the same phenotype (CD45RO, CD3, CD30 positive). An increased expression of HLA-DR antigen was observed in endothelial and Schwann cells. Chemotherapy with CHOP-Bleomycin markedly relieved her pain. These findings suggest that a direct lymphocytic infiltration in the nerve may be associated with neuropathy in this case.

Effect of n-3 fatty acid supplementation on lipid peroxidation and protein aggregation in rat erythrocyte membranes

Human erythrocytes in the circulation undergo dynamic oxidative damage involving membrane lipid peroxidation and protein aggregation during aging. The present study was undertaken to determine the effect of n-3 fatty acid supplementation on lipid peroxidation and protein aggregation in the circulation and also the in vitro susceptibility of rat erythrocyte membranes to oxidative damage. Wistar male rats were fed a diet containing n-6 fatty acid-rich safflower oil or n-3 fatty acid-rich fish oil with an equal amount of vitamin E for 6 wk. n-3 Fatty acid content in erythrocyte membranes of rats fed fish oil was significantly higher than that of rats fed safflower oil. The degree of membrane lipid peroxidation and protein aggregation of rats fed fish oil was not significantly higher than that of rats fed safflower oil when the amounts of phospholipid hydroperoxides, thiobarbituric acid-reactive substances, and detergent-insoluble protein aggregates were measured. When isolated erythrocytes were oxidized under aerobic conditions in the presence of Fe(III), the degree of membrane lipid peroxidation of erythrocytes from rats fed fish oil was increased to a greater extent than that of rats fed safflower oil, whereas the degree of membrane protein aggregation of both groups was increased in a similar extent. Hence, n-3 fatty acid supplementation did not affect lipid peroxidation and protein aggregation in membranes of circulating rat erythrocytes, and the supplementation increased the susceptibility of isolated erythrocytes to lipid peroxidation, but not to protein aggregation, under the aerobic conditions. If a sufficient amount of vitamin E is supplied, n-3 fatty acid supplementation may give no undesirable oxidative effects on rat erythrocytes in the circulation.

The use of sequence comparison to detect 'identities' in tRNA genes

We have developed a computational method that detects 'identities' in tRNA genes by using principal component analysis to classify the sequences of bases in tRNA genes into groups of similar sequences and then comparing the distribution of sequences of bases, in order to extract characteristic bases that are conserved within a group but differ between groups. These classification and comparison procedures are applied recursively to classify the sequences into hierarchical groups, so that multiple levels of characteristic sites can be detected. By using this computational method, we were able to detect many characteristic sites in the T and D domains of tRNAs, as well as the characteristic sites that had already been detected experimentally. This suggests that bases not only in the contact regions but also in the elbow regions, which determine the structure and dynamics of the whole tRNA molecule, are important to the tRNA-aminoacyl tRNA synthetase recognition.

Nonshivering thermoregulatory responses in trained athletes: effects of physical fitness and body fat

We studied the difference of thermoregulatory responses between trained male athletes (TR, n = 9) and untrained men (UT, n = 7) during 60 min of cold exposure (15 degrees C) without shivering, and examined the effects of physical fitness and body fat on these responses. Mean skin temperature (Tsk), esophageal temperature (Tes), and skin conductance (Kb) were similar between TR and UT, and heat production (M) for TR increased significantly during exposure at 15 degrees C. The M at 15 degrees C correlated positively with maximal oxygen uptake and negatively with body fat (%BF), but not with Tes. The Kb correlated negatively with Tes and positively with Tsk. The %BF also correlated negatively with Kb and Tsk during exposure at 15 degrees C, and the slope of %BF vs. Tsk relationship was significantly steeper in TR than in UT. These results suggest that (1) body temperature is maintained by the reduction of skin conductance, and (2) heat insulation independent of body fat is enhanced in trained athletes during cold exposure without shivering.

Necessity of interleukin-1beta converting enzyme cascade in taxotere-initiated death signaling

Taxotere is a new type chemotherapeutic agent which targets tubulin. In the present study, we investigated the molecular machinery of taxotere-initiated death signaling. Taxotere induced cell death in mouse fibroblast L929 cells. Cell morphological analysis revealed that this effect showed characteristics of apoptotic and necrotic cell death. To further examine taxotere-induced cell death, we investigated the direct involvement of caspase. When cells were pretreated with the synthesized tetrapeptide inhibitor of caspase, YVAD-CHO (Ac-Tyr-Val-Ala-Asp-aldehyde: inhibitor of interleukin-1beta converting enzyme (ICE) subfamily) or DEVD-CHO (Ac-Asp-Glu-Val-Asp-aldehyde: inhibitor of CPP32 subfamily), taxotere-induced cell death was prevented. In addition, time course experiments demonstrated that activation of the ICE subfamily preceded activation of the CPP32 subfamily in taxotere-initiated death signaling, suggesting the direct involvement of the ICE cascade in taxotere-initiated death signaling. On the basis of these results, we suggest that taxotere causes the initiation of ICE cascade in its death signaling pathway and that the down-stream site of taxotere-initiated death signaling is the same as that of other chemotherapeutic agents.

Effect of hydration states on thermoregulatory responses during exercise in rats

Thermoregulatory response during exercise was studied in rats with three hydration states: euhydration, hypohydration (-18% plasma volume by thermal dehydration), and hyperhydration (+24% plasma volume by 5% bovine serum albumin solution infusion). Rats exercised (12.5 m.min-1) for 30 min at an ambient temperature of 25 degrees C. Abdominal temperature (Tab) and heart rate were continuously recorded by using a surgically implanted transmitter and telemetry system, and the tail skin temperature (Tts) was measured as an index of peripheral vasomotor tone. In the euhydration group, Tts showed an increase when Tab reached 37.6 degrees C; an increase of Tts was observed at 37.9 degrees C of Tab in the hypohydration group and at 37.4 degrees C in the hyperhydration group. The slope of the Tts-Tab relationship was steeper in the hyperhydration group and less steep in the hypohydration group than in the euhydration group. These results indicate that hypohydration leads to an upward shift in the body temperature threshold for tail vasodilation and an increase in Tab during exercise. Hyperhydration, however, leads to a downward shift of the threshold and the maintenance of a lower Tab. An elevation of the threshold Tab for vasodilation was observed when plasma volume was reduced by more than 20%, and a decrease was observed when plasma volume increased more than 15%.

[The relationship between smoking behavior and self-esteem among elementary and junior high school students]

OBJECT

This study examined the relationship between smoking behavior and self-esteem among Japanese early adolescents.

METHOD

The study sample comprised 1,486 fourth through ninth grade students from 10 elementary schools and six junior high schools throughout nine prefectures. Data were collected using an anonymous self-administered questionnaire which included items measuring smoking behavior, self-esteem, intention to smoke in the future, self-efficacy to refuse peer pressure to smoke, the smoking behaviors of their parents, siblings and friends. Self-esteem was measured using the Harter Perceived Competence Scale which includes four areas: cognitive, social, physical, and general.

RESULTS

The main results were as follows: 1) Ever smokers had lower cognitive and general competence scores, but a higher physical competence score than never smokers, especially among males. 2) Ever smokers had more smoking parents, siblings and friends than never smokers. 3) Ever smokers had stronger intention to smoke in the future than never smokers. 4) Ever smokers had lower self-efficacy to refuse peer pressure to smoke than never smokers.

CONCLUSION

The results of this study about the relationship between smoking behavior and self-esteem were consistent with those of some previous studies in the U.S. Therefore, it is suggested that effective smoking prevention programs for Japanese early adolescents should include strategies to enhance self-esteem.

Relationship between aerobic power, blood volume, and thermoregulatory responses to exercise-heat stress

To clarify the relationship between aerobic power (VO2max), blood volume (BV), and thermoregulatory responses to exercise-heat stress, we analyzed the cross-sectional relationship between the resting BV, plasma volume (PV), erythrocyte volume (EV), VO2max, forearm blood flow (FBF), and sweating responses during exercise in a hot environment (31 degrees C, 50% relative humidity). Twelve college-aged male subjects with a mean maximal oxygen uptake of 48 (range 42-59) mL.kg-1.min-1, a mean PV of 54 (range 42-72) mL.kg-1, a mean EV of 31 (range 23-43) mL.kg-1, and a mean BV of 85 (range 67-115) mL.kg-1 (measured by the Evans Blue dye dilution method) performed three sessions of 20-min cycle exercise at two levels of intensity (40% and 60% VO2max). The BV, PV and EV correlated positively with peak FBF (r = 0.596-0.711, P < 0.05), the increase of FBF in response to a unit rise in esophageal temperature (Tes; peak delta FBF/peak delta Tes) (r = 0.592-0.656, P < 0.05) and with total sweat loss (TSL) (r = 0.599-0.634, P < 0.05) during the exercise. The VO2max correlated with TSL during exercise at 40% VO2max (r = 0.578, P < 0.05), but not with peak FBF and peak delta FBF/peak delta Tes. The VO2max per lean body mass also showed a significant positive correlation with BV (r = 0.769, P < 0.01), PV (r = 0.706, P < 0.05), and with EV (r = 0.841, P < 0.001). The peak delta FBF/peak delta Tes was correlated positively with peak FBF (r = 0.597-0.830, P < 0.05-0.01) and negatively with peak Tes (r = 0.641-0.769, P < 0.05-0.01) during the exercise at the two levels. However, the chest sweat rate (CSR), TSL, and the increase of CSR in response to a unit rise in Tes (peak delta CSR/peak delta Tes) showed no correlation with peak Tes during the exercise at the two levels. These findings suggest that 1) heat dissipation responses during exercise were related more to blood volume than aerobic power and 2) skin blood flow was related more to body temperature than sweating responses during exercise under mild heat stress.

Iron-induced apoptosis in mouse renal proximal tubules after an injection of a renal carcinogen, iron-nitrilotriacetate

Redox-active iron was demonstrated in mouse kidney by Timm's sulphide-silver staining after an injection of a renal carcinogen, iron-nitrilotriacetate (Fe-NTA). The iron was on the apical site of tubular epithelia of the renal proximal convoluted portion and in the tubules of the straight portion 30 min after the Fe-NTA injection. As the epithelial cells of the proximal tubules died, the iron disappeared in the dead cells and was stored in the cytoplasm of the more distal tubular epithelia. Biochemically, redox-active iron in the kidney rapidly increased to four times higher than the control 30 min after the Fe-NTA injection, then decreased to a plateau which was still higher than the control. Iron tightly stored in iron-storage proteins increased gradually by 3 h after the injection and then decreased at 5 h. The iron-induced free radical injuries, such as lipid peroxidation and protein oxidation, were demonstrated in the renal proximal tubules by histochemistry. The nuclei of the proximal tubular epithelia shrank and fragmented with the free radical injuries, and were positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling. DNA ladder was demonstrated in the mice renal cortexes by agarose gel electrophoresis. It was elucidated that redox-active iron caused free radical injuries in the proximal tubules of mice kidneys after the injection of a renal carcinogenic iron (Fe-NTA) and induced the apoptosis of the proximal tubular epithelial cells.

Inhibitory effects of Chinese ant extract (CAE) on nephrotoxicity induced by ferric-nitrilotriacetate (Fe-NTA) in Wistar rats

We observed the inhibitory effects of Chinese ant extract (CAE), a Chinese traditional medicine, on nephrotoxicity induced by Fe-NTA in Wistar rat. Strong positive staining with Schiff's reagent was found in the proximal tubules of the untreated control rats. In contrast, the positivity was very weak in CAE treated rats. The level of TBARS was also higher in the untreated control rats than in CAE treated rats. Meanwhile, the scavenging effect of CAE on hydroxyl radicals was analyzed by electron spin resonance (ESR) in vitro. The results indicate that CAE can efficiently prevent Fe-NTA induced nephrotoxicity through quenching free radicals mechanism.

Copper and iron-induced oxidative damage in non-tumor bearing LEC rats

The copper and iron status in the liver of non-tumor bearing Long-Evans Cinnamon (LEC) rats (average age 17 months) was investigated. A direct quantitation of loosely-bound copper and iron was also investigated by using a chelating agent, nitrilotriacetic acid (NTA-chelatable free copper and iron). Besides the total copper and iron contents, the level of NTA-chelatable free copper was also higher in LEC rats than in LEA rats (P<0.05). But for the free iron level there was no significant difference between the two rat groups (P>0.05). The formation of thiobarbituric acid-reactive substances was higher in LEC rats than in LEA rats (P<0.01). The 4-hydroxy-2-nonenal (HNE)-modified proteins were also clearly demonstrated in LEC rat liver. The copper and iron which produced the most important effect in the process of oxidative damage in LEC rats could not be distinguished. Even though free copper, which could induce free radical injuries, was increased in LEC rats, neither tumor-induction nor preneoplastic lesions in the experimental LEC rats were observed. Therefore it is speculated that the elevation of a free iron is another important factor. Copper and iron, both important transition metals in the body, may participate in the induction of DNA damage and oncogenesis.

Characterization of B cells expressing recombination activating genes in germinal centers of immunized mouse lymph nodes

Products of recombination activating genes (RAG-1 and RAG-2) involved in the rearrangement of Ig genes have been shown to be expressed only in immature stages of B cells. However, we have recently found that RAG genes were re-expressed in mature mouse B cells activated in vitro and in germinal centers (GCs) of immunized mouse lymph nodes (LNs). Here, we report that RAG transcripts and their proteins were expressed in parallel with the formation of GCs in popliteal LNs from mice immunized in the hind footpads. Immunocytochemical analysis revealed that RAG+ B cells were localized within GCs and were present as apoptotic tingible body cells. RAG expression is not considered a nonspecific result of apoptosis, since apoptotic B cells generated by surface Ig-engagement did not express RAG genes. These results suggest a novel role of RAG products in the differentiation of B cells in GCs.

Characterization of B cells expressing recombination activating genes in germinal centers of immunized mouse lymph nodes

Products of recombination activating genes (RAG-1 and RAG-2) involved in the rearrangement of Ig genes have been shown to be expressed only in immature stages of B cells. However, we have recently found that RAG genes were re-expressed in mature mouse B cells activated in vitro and in germinal centers (GCs) of immunized mouse lymph nodes (LNs). Here, we report that RAG transcripts and their proteins were expressed in parallel with the formation of GCs in popliteal LNs from mice immunized in the hind footpads. Immunocytochemical analysis revealed that RAG+ B cells were localized within GCs and were present as apoptotic tingible body cells. RAG expression is not considered a nonspecific result of apoptosis, since apoptotic B cells generated by surface Ig-engagement did not express RAG genes. These results suggest a novel role of RAG products in the differentiation of B cells in GCs.

Improvement of protein secondary structure prediction using binary word encoding

We propose a binary word encoding to improve the protein secondary structure prediction. A binary word encoding encodes a local amino acid sequence to a binary word, which consists of 0 or 1. We use an encoding function to map an amino acid to 0 or 1. Using the binary word encoding, we can statistically extract the multiresidue information, which depends on more than one residue. We combine the binary word encoding with the GOR method, its modified version, which shows better accuracy, and the neural network method. The binary word encoding improves the accuracy of GOR by 2.8%. We obtain similar improvement when we combine this with the modified GOR method and the neural network method. When we use multiple sequence alignment data, the binary word encoding similarly improves the accuracy. The accuracy of our best combined method is 68.2%. In this paper, we only show improvement of the GOR and neural network method, we cannot say that the encoding improves the other methods. But the improvement by the encoding suggests that the multiresidue interaction affects the formation of secondary structure. In addition, we find that the optimal encoding function obtained by the simulated annealing method relates to nonpolarity. This means that nonpolarity is important to the multiresidue interaction.

2D NMR of the metabolic antioxidant dihydrolipoic acid and its derivatives

Dihydroplipoate and lipoate are physiological thiols which in addition to their coenzyme functions exhibit antioxidant activity. For NMR investigations of their protective mechanism in biological and model systems it is very important to know the full assignment of proton and carbon spectra of these molecules in water (D2O). An unambiguous assignment of proton and carbon NMR spectra has been made for dihydrolipoate and its short chain derivatives bisnor- and tetranor-lipoic acid in D2O and CDCl3 solutions using 2D NMR methods. Oxidation of dihydrolipoic acid produces substantial electron density deshielding of the carbons nearest to the SH groups with the largest shift found at the inner SH group (17.79 ppm in D2O, 16.93 in CDCl3) and almost no changes in the tail portion of the molecule. However, bisnor-dihydrolipoic acid and especially tetranor-dihydrolipoic acid have more carbon deshielding near the outer SH group of the molecule which correlates with their known diminished ion chelating activity. Moreover, the proton triplet at position 2 of lipoic acid has strong pH dependence (pK = 4.58) due to the close proximity to the carboxylic group and this feature may be used for monitoring pH.

Post-infectious encephalitis with anti-galactocerebroside antibody subsequent to Mycoplasma pneumoniae infection

Galactocerebroside (Gc) is a major component of myelin in both the peripheral and central nervous systems. Although it is regarded as an important glycolipid hapten of myelin in rabbit experimental allergic neuritis (EAN), its role in human demyelinating diseases is not known. We studied three post-infectious encephalitis (PIE) patients related to Mycoplasma pneumoniae infection. All three of three patients with encephalitis and M. pneumoniae infection were positive for Gc antibodies (100%), while 25% of 32 M. pneumoniae-infected patients without neurological disease were positive, and 3.8% of 52 healthy controls. This indicates anti-Gc antibody is induced by M. pneumoniae infection. One of the PIE patients, who had extraordinary high titer antibody to Gc, showed an extensive, diffuse white matter demyelination and poor recovery. Since circulating anti-Gc antibody induces central nervous system demyelination in animals with elevated antibody titers and disruption of the blood-brain barrier, anti-Gc antibody may have an important function in the increased demyelination in PIE patients after M. pneumoniae infection.

Iron coordination by catechol derivative antioxidants

Iron complexes of nitrocatechols with different substituent groups [1: -CH = CR2; 2: -CH2-CHR2; 3: -CH = CR'(R")] were synthesized and their effects on iron-induced free radical reactions of biological importance investigated. Catechol and nitrocatechol derivatives effectively inhibited iron-induced lipid peroxide-dependent lipid peroxidation. In the Fenton-like reaction, iron-catechol generated hydroxyl radicals more strongly than did iron citrate, and iron-nitrocatechol derivative 2 generated a small amount of hydroxyl radicals. The iron complexes of derivatives 1 and 3 did not generate hydroxyl radicals. Iron-catechol had the highest ratio of reduction to oxidation rate constants and the second was iron-nitrocatechol 2, suggesting that iron chelated by nitrocatechols 1 and 3 may be most difficult to reduce. To elucidate the structure and physical properties of the iron complexes, UV/vis absorption spectroscopic, ESR and 1H NMR studies were performed in aqueous and DMSO solutions. In aqueous solution at pH 7.4, iron complexes of the nitrocatechol derivatives were high-spin tris(nitrocatecholato)ferrate(III) with a characteristic ligand-to-metal charge transfer absorbance (pi -> d pi). The lambda max of iron-nitrocatechol derivative 2 was shorter than those of iron-nitrocatechol derivatives 1 and 3, suggesting that the reduction potential of iron-nitrocatechol 2 is higher than that of iron-nitrocatechols 1 and 3. Nitrocatechol derivatives with a conjugation structure can sequester the chelated iron more effectively than catechol and the derivative without the conjugation against free radical generation by keeping the iron in the ferric state, probably because of the reduction potentials.

[The short-term effect of a smoking prevention program for the upper graders of elementary schools--the results of intervention study for two years with quasi-experimental design]

The purpose of this study was to evaluate the short-term effect of a smoking prevention program for Japanese elementary school-children in the fifth and sixth grades. The program was developed with concepts found in the Know Your Body Program and the conclusions of a National Cancer Institute-convened Expert Advisory Panel, and focused on teaching about the short-term effects of smoking and on resistance to social pressures to smoke. The study was conducted with a quasi-experimental design. An intervention group (52 boys and 54 girls) received three sessions for both the fifth grade in 1992 and the sixth grade in 1993. Moreover, the intervention group received a pre-test before the first session and a post-test after the third session in each grade. A comparison group (102 boys and 91 girls) received the same tests at the same time as the intervention group, but did not receive any program on smoking prevention. The short-term effect of the program were evaluated using the results of the pre-test in the fifth grade and of the post-test in the sixth grade in both groups. The results were as follows: 1) Remarkable short-term effects of the intervention were seen in respect to awareness of the importance of not smoking in girls, and also in the knowledge of the short-term effects of smoking in both sexes. 2) The intervention was not effective with respect to intention to smoke at the age of 20 and self-efficacy of refusing to smoke in both sexes. 3) The short-term effects were not clear in the smoking behavior in both sexes because the rates of ever smokers and of monthly smokers were almost the same for two years between the intervention group and the comparison group. 4) The smoking behaviors of children, their parents and their best friends had little influence on the results of the post-test in the sixth grade.

Oxidative damages by iron-chelate complexes depend on the interaction with the target molecules

To elucidate that in iron-catalyzed oxidative damage the interaction of iron complex with the target molecules is important, the oxidative damage to plasmid DNA, protein and fatty acid has been compared using iron-chelate complexes with nitrilotriacetic acid (nta), citric acid, ethylenediamine-N,N'-diacetic acid (edda) and diethylenetriamine-N,N,N',N",N"-pentaacetic acid (dtpa). In the presence of hydrogen peroxide, plasmid pBR322 strand breaks occurred in the order of Fe-edda > Fe-citrate > Fe-nta > > Fe-dtpa. However, fragmentation of bovine serum albumin and diene conjugation of linoleic acid micelle occurred in the order of Fe-nta > Fe-edda > > Fe-citrate > Fe-dtpa = O, which were similar to hydroxyl radical production by these iron complexes and H2O2. Bleomycin-detectable free radical-promoting irons in these iron complexes were about 85% of iron in Fe-nta, Fe-citrate and Fe-edda, and only about 33% in Fe-dtpa. Not only hydroxyl radical productivity and free radical-promoting iron content in iron complex, but also the interaction of the complex with the target molecules determines the iron-catalyzed oxidative damage.

Ginseng extract scavenges hydroxyl radical and protects unsaturated fatty acids from decomposition caused by iron-mediated lipid peroxidation

This study was conducted to investigate whether or not the antioxidation effect of ginseng extract directly inhibits decomposition of unsaturated fatty acid caused by iron and hydrogen peroxide-induced lipid peroxidation, and whether this effect involves a hydroxyl radical-scavenging mechanism. Thiobarbituric acid-reactive substances (TBARS), gas chromatography, and electron spin resonance (ESR) spectrometer were used to measure lipid peroxidation, unsaturated fatty acid, and hydroxyl radical. The results showed TBARS formed and the loss of arachidonic acid during lipid peroxidation, and that hydroxyl radical formed by the Fenton reaction were completely inhibited by ginseng extract. This antioxidant effect of ginseng may be responsible for its wide pharmacological actions in clinical practice by a free radical reaction-inhibition mechanism.

[Postoperative care of neobladder using a detubularized intestinal segment]

Neobladder using a detubularized intestinal segment was constructed in 74 cystectomized patients between October 1986 and July 1994. There were 65 males (87.8%) and 9 females (12.2%) with an average age of 63 years (range 36 to 77 years). The mean follow-up period was 35 months (range 7 to 85). Problems of postoperative care assessed were continence, renal function, metabolic consequences, neoplasms and other complications. Moreover, the impact of these problems on the quality of life was evaluated by a self-administered questionnaire. Continence in the daytime was achieved in 70/74 (94.6%) patients. Nocturnal incontinence was noted in 15/74 (20.3%) patients. Serum BUN and creatinine levels were maintained within normal limits. Metabolic acidosis (base excess < -5.0 occurred in 7/74 (9.5%) patients, 4 patients of whom needed alkalizing agents. Colon adenomas in neobladder were found and resected in 3 patients. The other postoperative complications were stone formation in neobladder in 4 (5.4%), urethral stricture in 7 (9.5%) and ureteral stenosis in 3 (4.1%) patients respectively, which were satisfactorily corrected by endourological procedures. As to quality of life assessment, the majority was satisfied, whereas 11% of the patients reported emotional distress and limitations in the usual physical activities by nocturnal incontinence. Our finding suggest that nocturnal incontinence is the most important problem and we need longer follow-up to evaluate the problems of metabolic consequences and neoplasms of the urinary tract.