bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of R-(+)-and S-(-)-limonene on the respiratory tract in mice
Authors: Larsen S T , Hougaard K S , Hammer M , Alarie Y , Wolkoff P , Clausen P A , Wilkins C K , Nielsen G D
Published: April 2003

The effects of airborne R-(+)- and S-(-)-limonene were studied in conscious BALB/c mice by continuous monitoring respiratory rate (f), tidal volume (VT) and mid-expiratory flow rate (VD) during an exposure period of 30 min. Both enantiomers decreasedffrom a trigeminal reflex, i.e., due to sensory irritation. The exposure concentration decreasingf by 50% (RD50) in the first 10 min of the exposure period was estimated to be 1076 ppm for R-(+)-limonene and 1467 ppmforS-(-)-limonene. Resultsforsensoryirritation ofR –(+)-limonene in BALB/c mice and humans are in close agreement. The reported sensory irritation threshold is above 80 ppm in humans while the no – observed – effect level was estimated to be 100 ppm in mice. The enantiomers were devoid of pulmonary irritation or general anesthetic effects with R-(+)-limonene <1599 ppm and S-(-)-limonene <2421 ppm. R-(+)-limonene did not influence VT below 629 ppm. S-(-)-limonene increased VT above 1900 ppm. Both enantiomers induced a mild bronchoconstrictive effect above 1000 ppm.
In vitro and in vivo studies on chelation of manganese
Authors: Missy P , Lanhers M-C , Grignon Y , Joyeux M , Burnel D
Published: April 2003

This work deals with new chelating agents of manganese (Mn).

Out of 24 compounds chosen for their chemical structure supposed to be favorable for Mn complexation, six polyaminopolycarboxylic acids proved to be efficient for displacing Mn bound to serum bovine proteins in vitro: TTHA, DTPA, DPTA, DPTA – OH, HBED, EDTA (mobilization>50%).

The first five compounds were then tested in vivo on rats pretreated with MnC12. They exhibited only slight to moderate efficacy to diminish Mn in tissues and were ineffective on increased Mn concentration in whole blood; in addition, they had different and specific mobilizing effects on other essential elements (Fe, Zn, Cu).

Their limited efficacyin vivo could be due to the formation of very stable complexes between Mn2+ and different molecules such as hemoglobin and certain cytochromes, instead of Fe2+. This could disturb the functioning of the cellular respiratory chain, leading to an incomplete reduction of 02 with formation of free oxygenated radicals, reduction in the energy supply, and disturbance of the cytochromes renewal mechanism. All of these phenomena could accelerate cellular aging and explain the lack of efficacy ofthe chelating agents towards Mn neurotoxicity (Parkinson's syndrome).
Protection by selenium of lead-acetate-induced alterations on rat submandibular gland function
Authors: Abdollahi M , Rahmat-Jirdeh N , Soltaninejad K
Published: April 2003

Pure submandibular saliva was collected intraorally by micro polyethylene cannulation of anaesthetized rats using pilocarpine as a secretagogue. Twenty-four days treatment with lead acetate 0.05% in drinking water altered salivary function. Except for flow rate that was (P <0.01) increased by lead acetate, the reminder of parameters, concentrations of total protein and calcium and the activity of N-acetyl-β-D-glucosaminidase (NAG) in submandibular secretions were decreased significantly (P< 0.01) by lead acetate. Selenium (2.5 mg 1-l) in drinking water for 24 days did not induce any significant change in saliva secretory function. Pretreatment by selenium, prevented the lead acetate-induced decrease of NAG activity and concentrations of calcium and protein (P<0.01). The increased flow rate by lead acetate was also affected by selenium pretreatment and reached the level of control. It is concluded that selenium can protect rat submandibular gland function from lead-acetate-induced adverse effects. Properties of selenium as an antioxidant, free radical scavenger and maintenance of cell membrane integrity may be possible mechanisms of its protective effects.
Fatal weeverfish sting
Authors: Borondo J C , Sanz P , Nogué S , Poncela J L , Garrido P , Valverde J L
Published: April 2003

We report a case of fatal weeverfish sting. An 18-yearold man was stung on the left leg by a weeverfish, which he was attempting to capture while snorkelling off the coast of Majorca (Spain). The man felt intense pain, but managed to swim to his boat where he lost consciousness after boarding rapidly. An hour later, when examined by a doctor, the subject was found to be in cardiorespiratory arrest. Reanimation manoeuvres were unsuccessful. The most import post-mortem findings were in the skin and lungs. A puncture wound, which traversed the greater saphenous vein and was covered by an intense haemorrhagic infiltrate, was observed in the skin. The lungs showed haemorrhagic alveolar oedema.
Assessment of prenatal smoke exposure by determining nicotine and its metabolites in maternal and neonatal urine
Authors: Kohler E , Bretschneider D , Rabsilber A , Weise W , Jorch G
Published: April 2003

Urine specimens were collected from 75 pregnant women before childbirth and from their newborns within 48 postnatal hours. A high-performance liquid chromatography (HPLC) method was used to determine urinary nicotine and its metabolites, cotinine and trans-3'-hydroxycotinine (OH-cotinine) to objectivise prenatal smoke exposure. Using the sum ofnicotine metabolites as a marker, 34 women were classed as not exposed to smoke (< 15 nmol/l), 18 as passive smokers (15-400 nmol/l), and 23 as active smokers (> 400 nmol/l). The newborns of active smokers exhibited significantly (P < 0.001) higher nicotine metabolite concentrations than did those of either non-exposed women or passive smokers. A close correlation was found to exist between maternal and neonatal nicotine and cotinine concentrations (r = 0.8968 and r = 0.9205, respectively). For OH-cotinine, this correlation was particularly close when maternal, but not neonatal, OH-cotinine was adjusted to creatinine (r = 0.9792). The neonatal/maternal urine concentration ratios for cotinine and OH-cotinine were noted to not significantly depend on the time of postpartal urine collection. Within the first two postnatal days, the extent of current prenatal smoke exposure attributable to active smoking of the mother was best reflected by the urinary concentrations of cotinine plus OH-cotinine without adjustment to creatinine.
The miseries of passive smoiong
Authors: Nelson Ed
Published: April 2003

Passive smoking is defined as an involuntary exposure to a combined but diluted cigarette sidestream smoke (SS, gas and particle phases that are evolved fromthe smoldering end ofacigarettewhilethesmokerisnotpuffing) andthe exhaled smoke from smokers. SS contains numerous cytotoxic substances such as polycyclic aromatic hydrocarbons (PAHs), aromatic amines, nitrosamines, heavy metals, poisonous gases, pesticide residues, and radioactive elements in quantities much higher than those found from the cigarette mainstream smoke (MS) which is puffed by smokers. Passive smoking is found to be the cause of death from cancers and cardiac disease. Furthermore, it damagingly involves reproductive organs, the nervous system, genetic materials, and is particularly hazardous to mother and child during pregnancy and to those with a history of asthma, chronic infections, induced or earned immune deficiency, or predisposed susceptibility.
Aggressive atropinisation and continuous pralidoxime (2-PAM) infusion in patients with severe organophosphate poisoning: experience of a northwest Indian hospital
Authors: Singh S , Chaudhry D , Behera D , Gupta D , Jindal S K
Published: April 2003

OBJECTIVE: The aim of the study was to find whether continuous pralidoxime (2-PAM) infusion along with aggressive atropinisation improves the outcome in patients with severe organophosphate poisoning who require assisted ventilation.

METHODS: Sixteen patients admitted to the respiratory intensive care unit (RICU) with severe organophosphate poisoning and requiring assisted ventilation were included in the study. The compounds involved were phorate (six), dichlorvos (four), oxydimeton methyl (one), monocrotophos (one), methyl parathion (one) and in three it was unknown. After decontamination, they were given intravenous (iv) bolus atropine 5 mg at onset and then 2.5 mg every 5-10 min till atropinisation was achieved, and then maintained either by intermittent bolus doses or by continuous infusion if the required dose was large. They were also given continuous iv infusion of 2-PAM in dose of 7.5 mg/kg body weight/h (maximum 500 mg/h) after an initial bolus dose of 2 g.

RESULTS: The mean (± S.D.) dose of atropine was 735.02 ± 742.98 mg (range 85-3000 mg) with maximum dose on day 1. The mean (± S.D) duration of2-PAM infusion was 96.4±49.4 h (range 10-216 h). The mean (±S.D) duration of mechanical ventilation (MV) was 131.5 ± 95.65 h (range 4-336 h). Fourteen patients could be successfully extubated and two died of bronchopneumonia and sepsis (mortality 12.5%6).

CONCLUSION: Continuous 2-PAM infusion along with aggressive atropinisation after initial decontamination improved the outcome but notthe duration of MV in severely intoxicated patients with organophosphate compounds who required assisted ventilation in this case series.
The protective effect of taurine against thioacetamide hepatotoxicity of rats
Authors: Dorğru-Abbasoğlu S , Kanbağli Ö , Balkan J , Çevikbaş U , Aykaç-Tokerl G , Uysall M
Published: April 2003

Thioacetamide (TAA) administration (three consecutive intraperitoneal injections of 400 mg/kg at 24-h interval) to rats resulted in hepatic injury as assessed by the measurement of serum transaminase activities and histopathological findings. This treatment caused an increase in the levels of malondialdehyde (MDA), diene conjugates (DCs) and glutathione (GSH) and the activity ofsuperoxide dismutase (SOD), and a decrease in the levels of vitamins E and C and the activity of glutathione peroxidase (GSH-Px) in the liver of rats. Taurine administration (400 mg/kg, i.p., every 12 h and started 24 h prior to the first TAA injection) was found to decrease serum transaminase activities and hepatic lipid peroxidation without any significant change in hepatic antioxidant system. Histopathological findings also suggested that taurine has ameliorated effect on TAA-induced hepatic necrosis. These results indicate that taurine treatment, together with TAA administration, diminished the severity of the liver injury by decreasing oxidative stress due to its possible scavenger effect.
Reduction of uranium transfer by local chelation in simulated wounds in rats
Authors: Houpert P , Chazell V , Paquet F , Bailly T , Burgada R , Henge-Napolil M H
Published: April 2003

The aim of the paper is to develop a new approach to treat uranium-contaminated wounds. The efficacy of a local uranium chelator, carballylic amido bis phosphonic acid (CAPBP) was assessed using two different uranium compounds. Rats were contaminated by intramuscular injections of uranyl nitrate or an industrial U04 compound to simulate wound contamination. CAPBP was injected intramuscularly (im) or intraperitoneally (ip) at a dosage of 30,umol kg-. In one experiment, the local administration of CAPBP was combined with a systemic administration of ethane-1-hydroxy-1,1-biphosphonate (EHBP). The local CAPBP treatment resulted in increased retention of uranium at the wound site: about 30% for uranyl nitrate or U04 after the first day and about 15% of U04 after the third day. Consequently, it reduced uranium translocation into the blood and deposition in the kidneys and bone. The combined treatment reduced the uranium deposits in the kidneys, bone and carcass to about one-half of those observed in controls 3 days after U04 contamination. The local CAPBP treatment increased the interval of time between contamination and uranium deposit in the target organs. Thus, it can increase the efficacy of nonspecific local treatments or specific systemic treatments. It could be given rapidly through spray or gel after an accident.
Poisoning with Boophane disticha: a forensic case
Authors: du Plooy W J , Swart L , van Huysteen G W
Published: April 2003

Scales from the bulb are traditionally used as wound dressing after circumcision and as general wound dressing. Concoctions of the bulb taken orally cause sedation, analgesia, visual hallucinations, irrational behaviour, coma or death. A man ingested 150 ml of a concoction to see who placed a spell on him. He started to hallucinate, thinking that somebody was attacking him. He pulled his gun and fired shots randomly, killing one person and injuring others. A gas chromatograph/mass spectrometer was used to analyze a sample of the concoction. The sample contained buphandrin, buphanine and crinamidine (alkaloids) and eugenol. Buphanine has a pharmacological action similar to that of hyoscine and, when ingested in toxic quantities, leads to excitement, agitation, hallucinations and coma. Eugenol is a volatile oilwithanalgesicproperties.Althoughitcould notbe proved that the concoction was only from Boophane disticha, the components were similar to those found in Amaryllidaceae to which Boophane belongs. The man's behaviour could be ascribed to the ingestion of compounds found in B. disticha.
Neuroparalysis and oxime efficacy in organophosphate poisoning: a study of butyryicholinesterase
Authors: Khan S , Hemalatha R , Jeyaseelan L , Oommen A , Zachariah A
Published: April 2003

The temporal profile of butyrylcholinesterase (BuChE) and in vitro pralidoxime-reactivated BuChE was studied in a cohort of 25 organophosphate-poisoned patients to examine their relationship to the development of intermediate syndrome and to understand reasons for lack of efficacy of oxime treatment. The clinical severity of poisoning (assessed by the Namba Scale) correlated significantly with the severity of intermediate syndrome. BuChE activity increased significantly over time and showed significant relationship to muscle power. The temporal profile of the enzyme was correlated to the clinical severity of poisoning. Reactivation potentials of BuChE (the difference between oxime-reactivated and-unreactivated enzyme activity) declined significantly with time after organophosphate ingestion. The reactivation potential of the enzyme at admission decreased significantly with increasing severity of poisoning and was lower in patients who developed intermediate syndrome. Patients who received oxime prior to hospitalization had a higher rate of intermediate syndrome and lower levels of BuChE at admission than those who had not. The study suggests that (i) BuChE reflects the clinical course of poisoning, confirming earlier studies; (ii) intermediate syndrome may be associated with a persistent inhibition of BuChE; and (iii) the lack of oxime efficacy in our patients maybe due to their severity of poisoning and the timing of oxime treatment.
Deferoxamine toxicity in hepatoma and primary rat cortical brain cultures
Authors: Christensen D W , Kisling R , Thompson J , Kirby M A
Published: April 2003

Deferoxamine is commonly used for treatment of iron intoxication. Because the usual dose is unable to chelate sufficient iron before severe injury occurs, “high-dose” deferoxamine treatment has been proposed. However, several authors have reported severe toxicity after deferoxamine therapy. Although the hemodynamic effects are well described, the cellular toxicity of deferoxamine is unknown. Accordingly, we investigated the cellular toxicity of deferoxamine using in vitro techniques in two cell lines. Brain cells were harvested from fetal rats and cultured for 14-21 days beforedeferoxamineexposure.Usingsimilartechniques,rat hepatoma cells were grown until confluent. Deferoxamine was added to the cultures to achieve final concentrations of 200-800 μg/ml, corresponding to in vivo infusion rates of 15-60mg/kg/h.Deferoxaminewasremovedafter3or6days by changing the medium. Subtoxic FeCl3 (500 mg/dl) was concurrently added to identical cultures to determine if deferoxamine potentiated iron toxicity. Cell viability was measured by a colorimetric assay. The addition of deferoxamine (0.2, 0.4, 0.8 mg/ml) significantly decreased cell viability in both cell groups. The effect of deferoxamine on primary cortical brain cultures was similar for the three concentrations used, and was similar when examined either 72 h or 6 days later. In contrast, hepatoma cell cultures evidencedadose-dependentcelllossthatincreasedwiththe lengthofexposure.TheadditionofsubtoxicamountsofFeCl3(500 μg/dl) in the presence of deferoxamine was protective in all cultures, and abolished deferoxamine-induced cell loss. Interestingly, the addition of serum albumin significantlyreducedtheamountofironpresentincells,suggesting its potential use to treat iron toxicity. These results suggest that deferoxamine, in the absence of iron, is toxic to cortical brain and hepatoma cells in vitro.
Immunotoxicological investigations on rats treated subacutely with dimethoate, As3+and Hg2+ in combination
Authors: Institóris L , Siroki O , Ündeger Ü , Basaran N , Dési I
Published: April 2003

Effects of combined exposure with dimethoate (DM), HgCl2(Hg),andNaAsO2 (As)wereinvestigatedfollowinga28-day oral exposure in male Wistar rats. In preliminary experiments, the LOEL (Lowest Observed Effect Level) and NOEL (Non Observed Effect Level) doses of the substances were determined using the same experimental system [determination of body weight gain, organ weights of brain, thymus, heart, lung, kidneys, adrenals, spleen, testicles, popliteal lymph node, white blood cell (WBC) and red blood cell (RBC) count, haematocrit (Ht), mean cell volume (MCV) of RBCs, cell content of the femoral bone marrow, IgM-plaque forming cell (PFC) content of the spleen, delayed type hypersensitivity (DTH) reaction] and animal strain. In the combination studies, LOEL dose of DM (28.2 mg/kg) was combinedwithNOELdosesoftheheavymetals(HgCl2 =0.40 mg/kg, NaAsO2 =3.33 mg/kg), and vice versa (DM=7.04 mg/kg, HgCl2 =3.20 mg/kg, NaAsO2 =13.3 mg/kg). In the DM–Hg combinations, significant alterations were found versus the corresponding high-dose internal control in the body weight gain, relative liver and kidney weights, and in the PFC response. When DM was combined with As, interactions were indicated by changes of relative liver weight, MCV value, and the PFC content of the spleen.

These results support the theory that the interactions between pesticides and heavy metals may modify the toxic effects of the single substances, and may also change the functional detection limits of the exposure. The changes in the functional detection limits, if they occur, can lead to false-positive and false-negative results in human epidemiological studies.
Reproductive toxicity of DDT in adult male rats
Authors: Rhouma K Ben , Tébourbi O , Krichah R , Sakly M
Published: April 2003

The reproductive toxicity of DDT was investigated in adult male rats exposed to 50 and 100 mg/kg body weight (b.wt) day 1 for 10 successive days. Compared with control animals, administration of DDT led to a dose-dependent reduction of testicular weight and the number as well as the percentage of motile spermatozoa in the epididymis. Testicular histological observationsrevealed alsoamarkedloss of gametes in the lumen of seminiferous tubules. In DDT treated rats, the seminal vesicles weights dropped significantly, resulting from a decrease of testosterone production by testes, whereas serum LH and FSH increased after pesticide exposure. This increase of gonadotrophin levels may be related to an impairment of the negative feedback exerted by the steroid on the hypothalamic–pituitary axis. It is concluded that DDT induced adverse effects on male rat fertility by acting directly on the testes and altering the neuroendocrinefunction.
Assessment and management of acute poisoning by petroleum products
Authors: Seymour F K , Henry J A
Published: April 2003

Petroleum products are highly complex chemical mixtures consisting predominantly of hydrocarbons. Their composition varies with source and intended use of the product. Virtually all are blended products that come into contact with man in a wide range of circumstances. Their toxicity for man is generally low and the use of additives rarely affects the toxicity of the final product. Because products are blended to meet performance, and not chemical specifications, their composition varies significantly. Management of toxicity benefits from simplified guidelines that consider the product by its type. Management in most cases is symptomatic, but the doctor needs to be aware of the potential for development of sequelae such as aspiration pneumonia and central nervous system (CNS) depression. Local and systemic effects of exposure to hydrocarbons are reviewed, as are immediate assessment and recommended management of acute exposure to petroleum products. Because of the large scope of this subject, this paper limits itself to acute toxicity of petroleum products encountered inthe public domain. It does not address topics such as chronic toxicity, solvent abuse, petrochemicals, or pesticides.
Oxygen reactive radicals production in cell culture by okadaic acid and their implication in protein synthesis inhibition
Authors: Matias W G , Traore A , Bonini M , Sanni A , Creppy E E
Published: April 2003

Okadaic acid (OA), a diarrhetic shellfish toxin is a potent promoter of tumours in mouse skin and a specific inhibitor of protein phosphatases 1 and 2A. Recently it has been shown that OA inhibited protein synthesis in a cell-free system, with 50% inhibitory concentration of 6.3610712 M but the mechanism whereby this inhibition is mediated was still unclear. In the present study, the effect of OA on protein synthesis in Vero cell cultures was investigated. Protein synthesis was inhibited by OA alone in Vero cells in a concentration-dependent manner (IC50=27 ng/ml i.e. 3.361078 M). Since OA also induced lipid peroxidation and likely oxygen reactive radicals, it was interesting to know whether these radicals impair the protein synthesis process. Therefore, SOD+catalase known as scavenger of active oxygen radicals were added in the culture medium in the presence of OA and labelled leucine. These enzymes partially prevented the inhibition of protein synthesis induced by OA, indicating that the formation of high reactive oxygen free radicals could be one of the pathways this marine toxin induces its toxicity. Since the prevention by SOD+catalase was only partial (the IC50 increased from 27 ng/ml to 48 ng/ml i.e. 3.361078 M to 5.961078 M)itwas speculated that the production of oxygen reactive radical scavengered by SOD+catalase is not the main mechanism whereby OA induces its cytotoxicity. Vitamins E and C completely prevent the lipid peroxidation induced by OA in cells, but failed to reduce the inhibition of protein synthesis to the same level, indicating that a more specific mechanism might be responsible for protein synthesis inhibition. That is the hyperphosphorylation of elongation factor EF-2 in the protein synthesis machinery. However our results pointed to lipid peroxidation being a precocious phenomenon following the OA exposure, since a concentrationwithenhancedMDAproductionwaslower than that inducing significant cellular protein synthesis inhibition.
Dose-response relationships in chemical carcinogenesis reflect differences in individual susceptibility. Consequences for cancer risk assessment, extrapolation, and prevention
Authors: Lutz W K
Published: April 2003

The shape of the dose-cancer incidence curve observed in an animal bioassay for carcinogenicity of a chemical is the result of a superposition of various mechanisms contributing to the process of carcinogenesis. For genotoxic carcinogens, for instance, a sublinear (convex; up-bent) shape could be the result of a saturation of DNA repair or of a higher rate of cell turnover associated with high-dose cytotoxicity and regenerative hyperplasia. In human cancer epidemiology, the situation is more complex. The human population is very heterogeneous with respect to both genetic and life-style factors that modulate the process of tumor formation. Therefore, individuals are expected to show widely variable susceptibility to carcinogenic factors, and the dose-response curve is in fact a reflection of the tolerance distribution. Each modulating factor divides the population up into sub populations of different susceptibility so that nonlinearities that could be present in a homogeneous population are flattened out. A linear extrapolation of a human cancer risk to low dose might therefore be appropriate under certain conditions even if the dose-response curve in animals has a strongly sigmoidal shape. For cancer prevention, the investigation of susceptibility factors is expected to be of great value. The elimination of concurrent risk factors in high-risk subpopulations or individuals might be more effective than a minor general reduction of a tolerable exposure level.
Maternal passive smoking during pregnancy and foetal developmental toxicity. Part 2: histological changes
Authors: Nelson Ed , Goubet-Wiemers Carla , Guo Yuanjian , Jodscheit Karin
Published: April 2003

1 Evidence has been accumulating on the growth suppressing effects of maternal passive smoking on foetus. Reviewing all literature released during the last two decades and screening for all possible variables such as previous smoking history, maternal age and weight gain, parity and length of gestation, placental weight, and diet, we found no reason to doubt the role of passive smoking during pregnancy in the induction of growth retardation. However, no literature indicates whether these birthweight deficits might hint at other possible hidden abnormalities in tissues. To verify this question, we performed an experiment on rats. 2 We have already reported that pups born to rats with previous exposure to cigarette' sidestream smoke during pregnancy showed a significant and dosedependent growth retardation.1 Those pregnant rats were exposed each in a 150 dm3 glass chamber to diluted sidestream smoke of either 1, 2, 3 or 4 commercial blond filter brand cigarettes during either first, second or third week of pregnancy. We have selected a part of each group of pups at random and examined for possible histological changes of lung, liver, stomach, kidney and intestinal tissues. 3 Compared to controls, lung tissues of newborns of smoke exposed mothers showed an enhanced incidence of apoptosis, mesenchymal changes, and hyperplasia of bronchial muscles. Pronounced abnormal changes in haematopoiesis and proliferation of bile duct cells were the most variations from norm observed in liver tissues of exposed pups. Immature glomeruli of kidney, epithelhypoplasia of stomach, and hypoplasia of intestinal villi were common among newborns of exposed mothers than among controls. 4 These results indicate that passive smoking upon pregnancy causes abnormal morphological changes in internal tissues of newborns. At present, we can draw no conclusion as to whether these histological changes will result in functional malformations or possibly late effects, although they should be expected.
Hair analysis–a biological marker for passive smoking in pregnancy and childhood
Authors: Klein J , Koren G
Published: April 2003

Passive smoking has been shown to adversely affect the health of infants and children. We used hair analysis for nicotine and its metabolite cotinine as a biological marker for exposure to smoking in these two groups. Using radioimmunoassay we measured maternal and fetal hair concentrations of nicotine and cotinine in the motherinfant pairs belonging to three different groups based on the mother' smoking habits. The three groups were: active smokers, passive smokers and nonsmokers. There was a significant correlation between maternal and neonatal hair concentration for both, nicotine and cotinine. Mothers and infants in the smoking groups, both active and passive, had significantly higher hair concentrations of both, nicotine and cotinine than in the control, nonsmoking group. In an older cohort, we compared two groups: 78 asthmatic children were compared to 86 healthy children exposed to similar degrees of passive smoking. By using objective, biological markers, our study aimed at verifying whether asthmatic children are different from nonasthmatic children in the way their bodies handle nicotine. Our results show, that, despite the fact that parents of asthmatic children tend to smoke a lower number of cigarettes per day, their children had an average twofold higher concentrations of cotinine in their hair then the control, nonasthmatic children.

These studies document the importance of hair analysis as a tool for measuring exposure to cigarette smoke.
Variations in the distribution of okadaic acid in organs and biological fluids of mice related to diarrhoeic syndrome
Authors: Matias W G , Traore A , Creppy E E
Published: April 2003

Okadaic acid (OA) is the main toxin produced by dinoflagellates which can accumulate in the hepatopancreas of mussels and cause diarrhetic shellfish poisoning in consumers. This toxin is also a tumour promoter and a specific potent inhibitor of protein phosphatases 1 and 2A. No specific target organ is known for this toxin. This study concerns the distribution of [3H]OA in organs and biological fluids of Swiss mice having received a single dose per os of AO (50 mg/kg). The determination of the toxin extracted from mouse organs 24 h after administration of [3H]OA and derivatised with 9-anthryldiazo methane (ADAM) before HPLC and fluorescent detection showed the highest concentration in intestinal tissue and stomach. This distribution was even more pronounced in intestinal tissue, when animal were given per os 90 mg/kg which induced diarrhoea. The high concentrations of [3H]OA in intestinal tissues and contents 24 h after administration demonstrates a slow elimination of OA. When the dose of OA was increased from 50–90 mg/kg, the concentrations of the toxin in the intestinal content and faeces increased proportionally. A good correlation was found between an increase of OA in the intestinal tissue and the diarrhoea in animals given 90 mg/kg orally. Moreover OA was present in liver and bile and in all organs including skin and also fluids. Altogether these results confirmed an enterohepatic circulation of OA as previously shown. These data also revealed that in acute OA intoxication the concentration of the toxin in the intestinal tissues reaches cytotoxic concentrations in accordance with the diarrhoea which is the main symptom of OA poisoning.
Karyomegaly of tubular cells as early stage marker of the nephrotoxicity induced by ochratoxin A in rats
Authors: Maaroufi K , Zakhama A , Baudrimont I , Achour A , Abid S , Ellouz F , Dhouib S , Creppy E E , Bacha H
Published: April 2003

Cases of karyomegaly were described by Sclare30 and by Mihatch31 in patients affected with tubular-interstitial nephropathy. The Karyomegalic cells showed enlarged nuclei with accumulation of genetic material. No aetiology was suggested.

Our study of rats experimentally intoxicated by ochratoxin A, a well-known nephrotoxic compound, indicates the presence of karyomegaly with alteration of the tubular tissue. In control animals no karyomegalic cells were detected. These observations suggest that karyomegaly with megacytosis may be caused by the nephrotoxic ochratoxin A in the kidney.

In addition abnormal mitosis together with karyomegalic cells were observed at an earlier stage of the intoxication (30 days) suggesting possible regeneration if the OTA insults are stopped.

After 90 days of treatment, the degeneration increased and only karyomegalic and apoptotic-like cells were observed indicating that the regeneration no longer occurs and that the degeneration becomes irreversible.
Ocular thrombosis and retinal degeneration induced in female F344 rats by 2-butoxyethanol
Authors: Nyska A , Maronpot R R , Ghanayem B I
Published: April 2003

2-butoxyethanol, used extensively for domestic and industrial purposes, was tested in our experiments for its potential to cause damage to female rat ocular tissues. Female rats were previously found to be particularly sensitive to 2-butoxyethanol. A group of eight female F344 rats (2–3 months old) were exposed by gavage to 250 mg of 2-butoxyethanol/kg b.w. per day for 3 consecutive days and sacrificed 24 h after the last dose. Eight female rats received the dosing vehicle (water) and served as controls. At necropsy, petechial hemorrhages were noted on the sclera. Microscopic examination revealed treatmentrelated effects in the eyes, in addition to other known effects of BE exposure such as disseminated thrombosis and necrosis and infarction in various organs. The spectrum of histopathological changes noted in the eyes included hemorrhages localized in the posterior layers of the retina, leading to photoreceptor degeneration. Thrombi were identified in ciliary processes and limbal blood vessels. Histological changes suggestive of the retinal ischemic-infarctive process were also noted. Possible pathogenic mechanisms of 2-butoxyethanol-induced retinopathy are discussed.
Synthesis, Structure, and Phosphine-Induced Degradation of a Ruthenapentaborane Cluster with a Sterically Demanding Hexamethylbenzene Ligand
Authors: Kawano Yasuro , Kawakami Hiroyuki , Shimoi Mamoru
Published: April 2003

The reaction of [(η6-C6Me6)RuCl2]2 with excess BH3·THF produced a ruthenaborane cluster, arachno-[(η6-C6Me6)RuB4H10] (1). Compound 1 underwent cluster degradation through the action of Pme3 to afford arachno-[(η6-C6Me6)Ru(Pme3)B3H7] (2).
Cleavage of 2-Methoxyethoxymethyl Ethers Catalyzed by Cerium(IV) Ammonium Nitrate (CAN) in Acetic Anhydride
Authors: Tanemura Kiyoshi , Suzuki Tsuneo , Nishida Yoko , Satsumabayashi Koko , Horaguchi Takaaki
Published: April 2003

The reactions of 2-methoxyethoxymethyl (MEM) ethers 1 with a catalytic amount of cerium(IV) ammonium nitrate (CAN) in acetic anhydride gave the corresponding mixed acetal esters 2 and acetates 3.
A Solution Route to Synthesize Nickel Thiospinels
Authors: Shimizu Youichi , Yano Tomoyasu
Published: April 2003

Ni3S4, CoNi2S4, and NiCo2S4 thiospinels were synthesized by a pH-controlled homogeneous precipitation method at 70 °C with metal-chlorides and thioacetamide in the ammonium chloride–ammonia buffer solutions adjusted to pH = 9.9.
Hydrothermal Soft Chemical Synthesis of Ni(OH)2–Birnessite Sandwich Layered Compound and Layered LiNi1/3Mn2/3O2
Authors: Feng Qi , Xu Yaohua , Kajiyoshi Koji , Yanagisawa Kazumichi
Published: April 2003

A layered lithium nickel manganese oxide, Li1Ni1/3Mn2/3O2, has been hydrothermally prepared from a sandwich nickel manganese hydroxide–oxide precursor, Ni7Mn14O27(OH)10·nH2O, which has been hydrothermally synthesized at 200 °C by intercalating Ni(OH)2 into layered birnessite. In this precursor, MnO2 layer and Ni(OH)2 layer alternately pack together to form sandwich-like layered structure. The compounds were characterized by XRD and IR spectrum.
Reaction of Stable Silylene–Isocyanide Complexes with Boranes: Synthesis and Properties of the First Stable Silylborane–Isocyanide Complexes
Authors: Takeda Nobuhiro , Kajiwara Takashi , Tokitoh Norihiro
Published: April 2003

Stable silylene–isocyanide complexes [Tbt(Mes)SiCNAr (Ar = Tbt, Mes*; Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl; Mes = mesityl; Mes* = 2,4,6-tri-t-butylphenyl)] reacted with BH3·THF to give the first stable silylborane–isocyanide complexes [Tbt(Mes)SiHBH2CNAr]. The thermal equilibrium between Tbt(Mes)SiHBH2CNAr and TbtSiH2BH(Mes)CNAr was observed.
Palladium-Catalyzed Benzylic C–H Borylation of Alkylbenzenes with Bis(pinacolato)diboron or Pinacolborane
Authors: Ishiyama Tatsuo , Ishida Kousaku , Takagi Jun , Miyaura Norio
Published: April 2003

Borylation at the benzylic C–H bond of alkylbenzenes with bis(pinacolato)diboron [(Me4C2O2)B–B(O2C2Me4)] or pinacolborane [(Me4C2O2)B–H] was carried out at 100 °C in the presence of a catalytic amount of 10% Pd/C. The reaction selectively afforded pinacol benzylboronates in good yields directly from various alkylbenzenes.
Unusual Metal-Dependent Acceleration and Deceleration in the Metal-Catalyzed Hydrosilylation of Olefin Using Pyridyldimethylsilanes
Authors: Itami Kenichiro , Mitsudo Koichi , Nishino Akira , Yoshida Jun-ichi
Published: April 2003

The Rh- and Pt-catalyzed hydrosilylations of olefin utilizing 2-pyridyl-, 3-pyridyl-, 4-pyridyl-, and phenyldimethylsilane are described. Whereas huge rate acceleration was observed with 2-PyMe2SiH in the Rh-catalyzed reaction, huge rate deceleration was observed with 2-PyMe2SiH and 4-PyMe2SiH in the Pt-catalyzed reaction.
Effects of Salt, Acid and Base on the Decomposition of 2-Chlorophenol in Supercritical Water
Authors: Lee Geun-hee , Nunoura Teppei , Matsumura Yukihiko , Yamamoto Kazuo
Published: April 2003

The effect of salt, acid and base as additives on the decomposition of 2-chlorophenol (2CP) in supercritical water was investigated. Four additives were selected, NaCl as a salt, HCl and H2SO4 as acids, and KOH as a base. The addition of salts and acids had a little effect on the decomposition of 2CP in supercritical water (SCW), but that of bases showed a significant effect to enhance the decomposition rate.
Magnetic Alignment of Poly(carbonate)
Authors: Aoki Hisashi , Yamato Masafumi , Kimura Tsunehisa
Published: April 2003

An external magnetic field was applied to poly(carbonate) undergoing melt crystallization under a chemical reaction with organic salts. The solidified sample exhibited crystal orientation with the c-axis aligned parallel to the applied magnetic field.
Lower Rim 1,3-Disubstituted Derivatives of Calix[4]arene Amides Having Amino Acid Ester and Amines as Pendants
Authors: Rao P V , Rao C P , Kolehmainen E , Wegelius E K , Rissanen K
Published: April 2003

Lower rim modification of calix[4]arene at its 1,3-alternate positions to result in the molecules of potential importance possessing amide bonds and other functional moieties as generated from the reaction between calix[4]arene-1,3-diacid and the amino acids and/or substituted amines was carried out and the structural properties of the products were addressed.
A Novel Reaction Pathway in Olefin-Deuterium Exchange Reaction inside the Micropores of Rh(II) Dicarboxylate Polymer Complexes
Authors: Naito Shuichi , Tanibe Tomonori , Saito Emiko , Miyao Toshihiro , Mori Wasuke
Published: April 2003

Three dimensional microporous polymers of Rh fumarate or Rh terephthalate complexes exhibited high catalytic activity for hydrogen exchange and hydrogenation of olefins at 200 K. The hydrogen exchange reaction takes place only inside the nanopores of the complexes without complete scission of C–H bond of olefin molecule.
Ab Initio Studies on the Relative Stabilities of Neutral and Ionic Forms of Acetic Acid–Methylamine Complex and β-Alanine in Various Solvents
Authors: Hwang Sungu , Jang Yun Hee , Chung Doo Soo
Published: April 2003

The preference between neutral and ionic forms of acetic acid–methylamine complex and β-alanine in solution was studied quantum mechanically. The solvents studied were water, methanol, CH2Cl2, and hexane, representing various polarities.
A Novel Heat-Resist Silicone Polymeric Material with Refractive Index Controllability
Authors: Yasuda Naoki , Yamamoto Shigeyuki , Wada Yuji , Yanagida Shozo
Published: April 2003

A novel heat-resist optical waveguide silicone copolymer was successfully developed, with refractive index controllability between 1.558 and 1.523 by partially changing the substituent in the side chain, and high transparency in the visible and near-infrared region, 0.6–1.7 µm.
Synthesis, Structure, and Reactions of the First Stable Aromatic S-Nitrosothiol Bearing a Novel Dendrimer-Type Steric Protection Group
Authors: Goto Kei , Hino Yoko , Takahashi Yusuke , Kawashima Takayuki , Yamamoto Gaku , Takagi Nozomi , Nagase Shigeru
Published: April 2003

A stable aromatic S-nitrosothiol was synthesized by taking advantage of a novel dendrimer-type steric protection group, and its structure was determined by X-ray crystallographic analysis. Its reactions including oxidation to a stable S-nitrothiol are described.
Boron–Metal Exchange Reaction of Silylboranes with Organometallic Reagents: A New Route to Arylsilyl Anions
Authors: Kawachi Atsushi , Minamimoto Takashi , Tamao Kohei
Published: April 2003

The boron–metal exchange reaction of (arylsilyl)boranes with alkyllithiums, potassium tert-butoxide, and methylmagnesium bromide affords the corresponding silyllithium, silylpotassium, and silylmagnesium compounds, respectively. Especially, the boron–lithium exchange reaction occurs even in hydrocarbon solvents such as toluene and hexane as well as in THF.
Can Cp2Zr(C2H4) Easily React with Hydrosilane? Theoretical Study
Authors: Sakaki Shigeyoshi , Takayama Tatsunori , Sugimoto Manabu
Published: April 2003

DFT calculations clearly show that a zirconocene–ethylene complex, Cp2Zr(C2H4), easily reacts with hydrosilane, SiH4, to afford either Cp2Zr(H)(C2H4SiH3) or Cp2Zr(SiH3)(C2H5). In the transition state, the Si–H anti-bonding σ*-orbital of SiH4 overlaps well with the π-back donating molecular orbital between Zr dπ and C2H4 π* orbitals.
A Dimeric Mixed-Anions Lead(II) Complex: Synthesis and Structural Characterization of [Pb2(BTZ)4(NO3)(H2O)](ClO4)3 {BTZ = 4,4′-Bithiazole}
Authors: Mahjoub Ali Reza , Morsali Ali
Published: April 2003

The reaction of mixture Pb(ClO4)2 and Pb(NO3)2 with 4,4′-bithiazole ligand yielded white crystals of [Pb2(C6H4N2S2)4(NO3)(H2O)](ClO4)3. In this complex the cationic part is in fact binuclear and contains two PbL2 groups linked via bridging NO3− anion. It also contains a water molecule and as well as 4,4′-bithiazole ligands in all cases are coordinated via nitrogen atoms. Three perchlorate anions are uncoordinated to lead(II) and the lone pair of valence electrons of the lead(II) ions appears to be stereochemically active. The coordinated water molecule is involved in hydrogen bonding acting as hydrogen-bond donors with two O atoms of perchlorate ions as potential hydrogen-bond acceptors.
Resonance Raman Spectroscopic Detection of Pyridylazo Complex Formed at Liquid–Liquid Interface in Centrifugal Liquid Membrane System
Authors: Ohashi Akira , Watarai Hitoshi
Published: April 2003

A new method of resonance Raman microprobe spectroscopy combined with a centrifugal liquid membrane (CLM) method was constructed and successfully applied to the detection of the complex of palladium(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) formed at the heptane/water interface. The depth profiles of resonance Raman intensities of Pd(II)–5-Br-PADAP complex along the axis perpendicular to the interface confirmed that the complex existed only at the liquid–liquid interface.
Thermal and Pressure Induced Spin Crossover of a Novel Iron(III) Complex with a Tripodal Ligand Involving Three Imidazole Groups
Authors: Sunatsuki Yukinari , Sakata Masafumi , Matsuzaki Susumu , Matsumoto Naohide , Kojima Masaaki
Published: April 2003

A novel spin crossover Fe(III) complex, [Fe(H3L)](ClO4)3·(4-fim)·H2O (H3L = tris[2-(((imidazol-4-yl)methylene)amino)ethyl]amine, 4-fim = 4-formylimidazole), was synthesized and the crystal structure was determined at 293 K. Cryomagnetic measurements revealed a two-step spin conversion and a pressure induced spin crossover was observed.
Synthesis, Characterization and Crystal Structure of the Water-Soluble, All-Inorganic Composition, A, β-Keggin Triniobium(V)-Substituted Polyoxotungstate
Authors: Nomiya Kenji , Hasegawa Takeshi , Noguchi Ryusuke , Nomura Kei-ichi , Takahashi Mizuto , Yokoyama Hironari
Published: April 2003

Triniobium(V)-substituted β-Keggin polyoxotungstate, K7[A, β-SiW9Nb3O40]·6H2O, as a soluble metal-oxide analogue and a metal-oxide support of the polyoxoanion-supported organometallic complexes, was synthesized, and the crystal and molecular structures of this polyoxoanion containing the Keggin A, β-SiW9 unit were successfully determined for the first time.
Preparation of “Confetti” Particles by Dispersion Copolymerization of Acrylonitrile/Styrene with Poly(ethylene glycol) Macromonomer
Authors: Chen Ming-Qing , Kaneko Tatsuo , Chen Chun-Hao , Akashi Mitsuru
Published: April 2003

The novel spherical particles on which nano-projections were uniformly distributed over the whole surface like “confetti” were prepared by dispersion copolymerization of acrylonitrile with styrene in ethanol/water mixed solvents in the presence of poly(ethylene glycol) (PEG) macromonomer. Transmission electron microscopy and laser light scattering studies showed particles with a narrow size-distribution. The diameter (ca. 150–1000nm) was controlled by changing the solvent composition and concentration of the PEG macromonomer.
Preparation of Li4/3Ti5/3O4 Thin Film Anode with High Electrochemical Response for Rechargeable Lithium Batteries by Sol–Gel Method
Authors: Rho Young Ho , Kanamura Kiyoshi , Umegaki Takao
Published: April 2003

A stoichiometric spinel Li4/3Ti5/3O4 thin film was prepared by a sol–gel method with poly(vinylpyrrolidone) (PVP) as an anode of rechargeable lithium micro-batteries. The prepared film was evaluated electrochemically by cyclic voltammetry (CV). One-time-coated thin film had 0.4 µm of thickness and showed high electrochemical response until 50 mV s−1. In this study, it was first reported that a thin film electrode with high electrochemical response was obtained by the sol–gel method with PVP.
An Efficient Method for the Preparation of Vicinal Tertiary Diamines by Reductive Coupling of Aminoacetals Mediated by Low Valent Titanium Iodide Species
Authors: Yoshimura Naritoshi , Mukaiyama Teruaki
Published: April 2003

Aminoacetals, easily prepared by condensation of aromatic aldehydes, secondary amines and alcohols, are reductively coupled by using low valent titanium iodide species to afford the corresponding coupling products, vicinal tertiary diamines, in good to high yields under mild reaction conditions.
Isolable Yet Highly Reactive Cationic Organoruthenium(II) Amidinates, [Ru(η6-C6R6)(η-amidinate)]+X−, Showing Signs of Coordinative Unsaturation: Isoelectronic Complexes of Ru(η5-C5Me5)(η-amidinate)
Authors: Hayashida Taizo , Yamaguchi Yoshitaka , Kirchner Karl , Nagashima Hideo
Published: April 2003

The coordinatively unsaturated ruthenium(II) complexes [Ru(η6-C6R6)(η-amidinate)]+X− (R = H, Me, X = TFPB, PF6), being isoelectronic with Ru(η5-C5Me5)(η-amidinate), have been isolated and characterized by spectroscopy and crystallography. A weak π-coordination of the amidinate ligands in the solid state was observed by X-ray crystallography. DFT calculations also suggest that such a coordination mode contributes to the stabilization of these complexes. These complexes behave as highly reactive transition metal Lewis acids in the reactions with various two-electron donor ligands.
Preparation of a New MOP Ligand Containing a Long-Chain Alkyl Group and Its Use for Palladium-Catalyzed Asymmetric Hydrosilylation of Cyclic 1,3-Dienes
Authors: Han Jin Wook , Hayashi Tamio
Published: April 2003

A new MOP ligand containing n-octyl group at 6 and 6′ positions of (R)-2-(diphenylphosphino)-2′-aryl-1,1′-binaphthyl skeleton was prepared and used for palladium-catalyzed asymmetric hydrosilylation of cyclic 1,3-dienes with trichlorosilane. By introduction of the n-octyl group, the palladium-phosphine catalyst became soluble in the reaction system, realizing high catalytic activity at a low reaction temperature.
Schülervorstellungen zum Boyle‐Versuch
Authors: Johannsmeyer Falko , Schneider Janine , Oetken Marco
Published: April 2003

DAS GESETZ von der Erhaltung der Masse spielt bei der Vermittlung der Kriterien chemischer Reaktionen im Anfangsunterricht eine wesentliche Rolle. Es kann bereits auf phänomenologischer Ebene — zusammen mit dem Charakteristikum der Stoffumwandlung sowie des Energieumsatzes — erarbeitet werden. Nach der Einführung des Daltonschen Atommodells findet die Massenerhaltung wiederum eine überzeugende Interpretation mit der Vorstellung von der Existenz und dem Erhalt der Atome bei chemischen Reaktionen.