bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation of VX and sulfur mustard by enzymatic haloperoxidation
Authors: Amitai G. , Adani R. , Hershkovitz M. , Bel P. , Rabinovitz I. , Meshulam H.
Published: July 2003

Chloroperoxidase (CPO) isolated from Caldariomyces fumago (20 U ml−1) together with urea hydrogenperoxide (UPER, 0.5 mM) and sodium chloride as co‐substrate (NaCl, 0.5 M) caused rapid breakdown of VX (10 µM) (t½ = 8 s, 25 C, 50 mM tartarate, pH 2.75). Glucose oxidase (GOX, Aspergillus niger) and glucose were used as an alternative source for H2O2. A mixture of GOX (20 U ml−1), glucose (GLU 0.45 M), CPO (20 U ml−1) and NaCl (0.5 M) caused a 3.8‐fold slower degradation of VX (10 µM) (t½ = 30 s, 25 C, 50 mM tartarate, pH 2.75). The concentrations of H2O2 and chlorine produced by this enzyme/substrate mixture depended mainly on the GLU concentration. Horseradish peroxidase (HRP) together with UPER (1 mM) and sodium iodide (NaI, 0.05 M) caused progressive degradation of VX that was more than 400‐fold slower than with CPO (20 U ml−1), UPER (0.5 mM) and NaCl (0.5 M) (t½ = 55 min, 25 C, pH 8). Skin decontamination of VX by CPO was tested in pig‐ear skin in vitro. The chemical agent VX (0.01 M, 100 µl) was degraded by 98% within 3 h of skin diffusion when a mixture of UPER/NaCl/CPO was applied 60 min prior to VX application. A mixture of UPER/NaCl without CPO also caused signiﬁcant VX degradation (94%) during skin diffusion whereas it did not cause any VX degradation in solution. Degradation of VX in skin, obtained without exogenous CPO, may indicate involvement of endogenous intradermal haloperoxidase‐like enzyme. Reagent UPER (1 mM) did not cause any degradation of VX in solution or during its skin diffusion. Furthermore, a mixture of CPO, UPER and NaCl caused rapid degradation of sulfur mustard (HD). Sulfur mustard (50 µM) incubated in the presence of CPO (4 U ml−1), UPER (0.05 M) and NaCl (0.5 M) at pH 2.75 and 30 C was oxidized by 97% and 99% within 5 and 10 min, respectively. The oxidation products HD sulfoxide, HD sulfone and HD sulfoxidevinyl were identiﬁed by GC/MS in the enzymatic chloroperoxidation mixture. Copyright © 2003 John Wiley & Sons, Ltd.
Leydig cell death in rats exposed to bismuth subnitrate
Authors: Pedersen Lars H. , Stoltenberg Meredin , Ernst Erik , West Mark J.
Published: July 2003

In a previous study, rats were treated with one injection of 500 mg kg−1 bismuth subnitrate intraperitoneally and maintained for 2 weeks. Bismuth was observed in Leydig cells, with a subsequent reduction in serum testosterone levels. In the present study, stereological procedures were used to estimate the number of Leydig cells in the right testis from the retained rats used in the previously published study.

The mean number of Leydig cells in the control group was estimated to be 18.7 × 106 (coefﬁcient of variation = 0.11), which is comparable to previous estimations. In the group exposed to bismuth the mean was 15.5 × 106 (coefﬁcient of variation = 0.18). The observed 17% difference between the two groups was statistically signiﬁcant (2P = 0.019). The inter‐individual variation was largest in the bismuth‐exposed group. Testis weight and body weight were not signiﬁcantly reduced after bismuth exposure.

These ﬁndings support the hypothesis that bismuth has a direct toxic effect on rat Leydig cells and underscores the potential risks of bismuth on male reproduction. Copyright © 2003 John Wiley & Sons, Ltd.
Iron status in manganese alloy production workers
Authors: Ellingsen Dag G. , Haug Egil , Ulvik Rune J. , Thomassen Yngvar
Published: July 2003

The aim of this study was to investigate markers of iron status in production workers with current and long‐term exposure to manganese (Mn) alloys. A total of 100 Mn‐exposed male workers were compared with 100 male controls matched for age in a cross‐sectional study. The geometric mean urinary Mn concentration in the exposed workers was 0.9 nmol mmol−1 creatinine (range = 0.1–126.3), compared with 0.4 nmol mmol−1 creatinine (range = 0.1–13.1) in the controls. The index group had been exposed to Mn for 20 years on average (range = 2.1–41.0). The geometric mean concentration of soluble transferrin receptor was lower in the exposed subjects than in the controls (2.2 vs 2.6 mg l−1; P < 0.001) and the concentration was negatively associated with current exposure to ‘soluble’ Mn in the inhalable aerosol fraction and with current smoking habits. An association was found between the concentration of serum soluble transferrin receptor and the concentration of Mn in whole blood (Pearson's r = 0.48; P < 0.001) in the controls. The results suggest that Mn‐exposed workers have higher intracellular iron concentration in the erythrocyte precursors than the controls, resulting in a down‐regulation of transferrin receptors on the surface of these cells. The concentrations of Mn in the blood of occupationally non‐exposed individuals appear to be inﬂuenced by iron status, even at physiological iron levels. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of sulfur mustard on transcription in human epidermal keratinocytes: analysis by mRNA differential display
Authors: Platteborze Peter L.
Published: July 2003

This study examines the transcriptional response of human epidermal keratinocytes (HEK) to sulfur mustard (HD) in order to gain a better understanding of the intracellular events that result in cytotoxicity. Differential display polymerase chain reaction technology was used to examine the relative transcriptional activity of healthy cells to those exposed to subvesicating or vesicating concentrations of HD for 4 h. Approximately 2% of the HEK transcriptome had altered expression. Sixty of the most prominently altered transcripts were characterized. Important upregulated genes include NADH dehydrogenase III, GADD45 and ubiquitin. Key downregulated genes include type I keratin 14, α‐enolase and caltractin. Many of the identiﬁed transcripts protein products presently do not have an assigned function and eleven transcripts were unidentiﬁable. These transcriptional alterations provide one of the ﬁrst molecular insights into the intracellular events induced by HD. Published in 2003 by John Wiley & Sons, Ltd.
Resveratrol, a natural aryl hydrocarbon receptor antagonist, protects lung from DNA damage and apoptosis caused by benzo[a]pyrene
Authors: Revel Ariel , Raanani Hila , Younglai Edward , Xu Jing , Rogers Ian , Han Robin , Savouret Jean‐Francois , Casper Robert F.
Published: July 2003

Benzo[a]pyrene (BaP) is an agonistic ligand for the aryl hydrocarbon receptor (AhR) and a major environmental carcinogen implicated in the aetiology of lung cancer through the induction of benzo[a]pyrene diol epoxidation (BPDE) and BPDE–DNA adducts. Because BaP metabolization requires cytochrome P‐450 1A1 (CYP1A1) induction through activation of the AhR, we hypothesized that resveratrol, a natural competitive inhibitor of AhR, could prevent these adverse effects of BaP on the lung. Balb‐C mice were injected for 5 weeks with corn oil, BaP (5 mg kg−1 week−1), resveratrol (50 mg kg−1 week−1) or BaP + resveratrol. Immunohistochemistry was performed on lung sections for the determination of CYP1A1 protein, BPDE–DNA adducts and apoptosis. A semi‐quantitative immunohistochemistry score (H score) was used for data analysis. Mice exposed to BaP had a signiﬁcant induction of lung BPDE–DNA adducts when compared with controls (H scores: control, 26, interquartile range 18–33; BaP, 276, interquartile range 269–288; P < 0.01). The BPDE–DNA adduct induction by BaP was abrogated signiﬁcantly by resveratrol (H score: BaP + resveratrol, 103, interquartile range 96–113). A similar pattern was found by immunohistochemistry for apoptosis (H scores: control, 121, interquartile range 102–137; BaP, 288, interquartile range 282–292, P < 0.05; BaP + resveratrol, 132, interquartile range 121–141, P = NS) and CYP1A1 (H scores: control, 170.3, interquartile range 164–175; BaP, 302.3, interquartile range 291–315, P < 0.05; BaP + resveratrol, 200.7, interquartile range 174–215, P = NS). Western blotting conﬁrmed that resveratrol prevented BaP‐induced CYP1A1 expression. This increase in CYP1A1 expression in response to BaP administration most likely causes BaP metabolism, BPDE–DNA adduct formation and subsequent apoptosis. All BaP‐induced effects could be prevented by resveratrol, suggesting a possible chemopreventive role for this natural phytoalexin against the development of lung cancer. Copyright © 2003 John Wiley & Sons, Ltd.
Harmonization of thresholds for primary skin irritation from results of human repeated insult patch tests and laboratory animal skin irritation tests
Authors: Tardiff Robert G. , Hubner Richard P. , Gevecker Graves Carol
Published: July 2003

Classiﬁcation of a chemical or chemical product as a primary skin irritant using laboratory animal tests has been deﬁned rigorously and codiﬁed in Consumer Products Safety Commission (CPSC) regulations. However, no regulatory agency, including the CPSC, has deﬁned a primary skin irritant threshold for human rapeat insult patch tests (RIPTs) that are typically conducted on products, such as cosmetics, anticipated to come into direct contact with humans. Further more, the protocols for animal and human tests are signiﬁcantly different, as are the schemes for grading responses. Consequently, comparing the results of one type of test with those from the other type has proved to be difﬁcult. In this short communication, we propose a procedure to harmonize the results from these two types of skin irritation tests and suggest that a score of ‘5’ in animal tests, considering 24‐h results on unabraded skin, is equivalent to a score of ‘3’ in human RIPTs. Copyright © 2003 John Wiley & Sons, Ltd.
Neurotoxic character of thimerosal and the allometric extrapolation of adult clearance half‐time to infants
Authors: Magos L.
Published: July 2003

The decomposition rate of organomercurials and the potency of the blood–brain barrier increase with the size of the organic radical. Thus methylmercury damages the brain more than thimerosal does, and when intake limits set for methylmercury are applied to thimerosal the safety margin is increased even if the clearances were the same. However, the clearance half‐time of ethylmercury in adults is about one‐third of the 50 days' clearance half‐time of methylmercury given for 60 kg body weight. Moreover, because metabolic rates (e.g. basal metabolism, daily loss of mercury in per cent of body burden) in different weight groups are related to the fractional power of body weight (rule of allometry), mercury clears from the infant body faster than from the adult body. Blood mercury concentrations observed after vaccination showed agreement with allometrically extrapolated concentrations. Copyright © 2003 John Wiley & Sons, Ltd.
Testicular and spermatotoxic effects of quinalphos in rats
Authors: Pant N. , Srivastava S. P.
Published: July 2003

Testicular and spermatotoxic effects were investigated in rats exposed to technical‐grade quinalphos (70%) at dose levels of 0.52 mg kg−1 (1/50th ld50) or 1.04 mg kg−1 body weight (1/25th ld50) for 5 days a week for 60 days. The activities of marker testicular enzymes such as sorbitol dehydrogenase (SDH) and acid phosphatase were signiﬁcantly decreased but those of lactate dehydrogenase (LDH), γ‐glutamyl transpeptidase (γ‐GT) and β‐glucuronidase were signiﬁcantly increased in a dose‐dependent manner. This particular pattern in the activity of testicular‐cell‐speciﬁc enzymes, an decrease in sperm motility and total epididymal sperm count and an increase in abnormal sperm suggest damage to germ cells and Sertoli cells. The testicular and spermatotoxic effects observed in rats may be due to the pesticide quinalphos or its metabolites. Copyright © 2003 John Wiley & Sons, Ltd.
Insights into the mechanism of erythrocyte Na+/K+‐ATPase inhibition by nitric oxide and peroxynitrite anion
Authors: Muriel Pablo , Castañeda Gilberto , Ortega Mónica , Noël François
Published: July 2003

Evidence shows that Na+/K+‐ATPase from kidney, brain and liver is inhibited by nitric oxide (NO) and peroxynitrite anion (ONO2−), but the mechanism is unknown. The aim of the present work was to study the inhibitory effect of NO and ONO2− on erythrocyte Na+/K+‐ATPase. Erythrocyte membranes were isolated from male Wistar rats by hypotonic washing. The membranes (free from haemoglobin) were incubated for Na+/K+‐ATPase activity measurement at various concentrations of ATP in the presence or absence of 400 µM SNAP (an NO donor) or 100 µM SIN‐1 (an ONO2− donor). At these concentrations, SNAP and SIN‐1 released about the same amount (100 µM) of NO or ONO2−, respectively, as monitored by measuring NO2− + NO3−. Both SNAP and SIN‐1 decreased Vmax by ca. 75% but they did not decrease the apparent afﬁnity of the Na+/K+‐ATPase for the substrate (a decrease of Km was even observed after SNAP treatment). The pattern of this inhibition is compatible either with oxidation of SH groups directly involved in ATP binding but in a way that is not surmountable by increasing the substrate concentration (‘non‐competitive’) or with oxidation of SH groups located outside the active site of the enzyme but important for the activity of the enzyme. Copyright © 2003 John Wiley & Sons, Ltd.
Replication of a psychosocial rehabilitation program: A case study analysis of supported education
Authors: Mowbray Carol T. , Gutierrez Lorraine M. , Bellamy Chyrell D. , Szilvagyi Steve , Strauss Shari
Published: July 2003

This article describes a strategy of organizing community stakeholder groups for the purpose of planning and implementing an innovative mental health program—supported education services for adults with mental illnesses who were interested in pursuing postsecondary education. A common planning framework was used in several different communities within the same state. The framework is described, as well as each community's characteristics and their planning and development activities—those typically identified in the literature as predictors of successful innovation diffusion efforts. We then present the outcomes of the planning process in each community and suggest conclusions about which community characteristics and/or planning activities seem to be most associated with success. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 437–457, 2003.
Interdisciplinary collaboration: An ongoing community narrative
Authors: Roos Vera , Lombard Antoinette
Published: July 2003

The current social problems in South Africa demand new levels of thinking, intervention, and educational and training models. We describe here how different disciplines of the Faculty of Humanities, University of Pretoria, collaborated in co‐creating opportunities for children living on the street by applying the principles of participatory action research. Cooperation among various disciplines is possible in a training and research context as well as in community interventions. Data for reflecting on the process was obtained from formal policy documents of the faculty as well as through accounts drawn from many of the participants involved. Interdisciplinary collaboration is more likely to occur if there is a continuous sharing of ideas and support of intrinsic creativity among all members involved. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 543–552, 2003.
Effectiveness of day treatment with proctor care for young children: A four‐year follow‐up
Authors: Whitemore Erin , Ford Monica , Sack William H.
Published: July 2003

This study evaluated the immediate and long‐term outcomes of a day treatment and proctor care model for preschool‐aged children. Seventy‐seven boys and 52 girls completed the program which combined day treatment, case management, individual and family therapy. Also, 60% of these clients were placed in proctor care homes which are short‐term family placements providing in‐home treatment. Results showed there was increased stabilization in family placements, with 67% of participants still living in a permanent family placement at the 4‐year follow‐up. Also, 69% of participants transitioned to a less‐restrictive academic placement and remained in regular classroom placements at follow‐up. Participants showed significant behavioral improvement at discharge and follow‐up on the Child Behavior Checklist. Participants also showed significant developmental improvement on the Battelle Developmental Inventory and the Expressive One Word Vocabulary Test. The results suggest that this treatment modality is effective in maintaining these children in the community and in producing positive long‐term outcomes. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 459–468, 2003.
Helpseeking behavior among Filipino Americans: A cultural analysis of face and language
Authors: Gong Fang , Gage Sue‐Je L. , Tacata Leonardo A.
Published: July 2003

In this study we explore the existing research on Asian Americans and helpseeking behavior, focusing primarily on Filipino Americans and the cultural variables of face and language. Although some important and specific cultural factors have been hypothesized to affect the helpseeking behaviors of ethnic minorities, very few empirical studies have been conducted to specifically test these hypotheses. To fill the gaps in previous research, we examined the influence of concern with face and of language abilities on helpseeking behavior for mental health problems among Filipino Americans. In addition, to obtain a more comprehensive understanding of helpseeking behavior, we divided the mental health care systems into four categories: lay, mental health specialty, general practitioner, and folk systems. Data are from the Filipino American Epidemiological Study (FACES) survey. The main statistical method we employed was logistic regression. Results from the descriptive analyses reveal that the lay system is the most frequently used source of care compared with the other systems of professional and folk systems for Filipino Americans. Furthermore, findings from the main effects models suggest that face and language are important cultural factors that contribute to the helpseeking behavior of Filipino Americans, but they have different influences on the four types of mental health care systems. The interaction analyses indicate that concern with face interacts with language abilities when predicting use of the lay system and the general medical sector. Despite these findings, to fully understand the dynamics of helpseeking, other cultural factors and longitudinal studies are needed. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 469–488, 2003.
The role of resource, protective, and risk factors on academic achievement‐related outcomes of economically disadvantaged Latino youth
Authors: Prelow Hazel M. , Loukas Alexandra
Published: July 2003

We examined the effects of cumulative risk, resource, and protective factors on the language and math achievement scores and school problem behaviors of a sample of 549 10–14‐year‐old, economically disadvantaged Latino youths. Findings indicated that as the number of risk factors increased, youth's language and math achievement scores decreased and school problem behaviors increased. Hierarchical regression analyses revealed that each of the hypothesized resource variables (i.e., maternal monitoring, maternal academic involvement, socioemotional competence, and extracurricular activity) made a unique contribution to at least one achievement‐related outcome, over and above the effects of cumulative risk. Moreover, maternal monitoring buffered the effects of multiple risk factors on language achievement scores. Contrary to expectations, higher levels of participation in extracurricular activities had a detrimental effect on male school problem behavior scores and was unrelated to girl's problem behavior scores. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 513–529, 2003.
An investigation of psychological sense of community in relation to Big Five personality traits
Authors: Lounsbury John W. , Loveland James M. , Gibson Lucy W.
Published: July 2003

In this study we examine the relationship between psychological sense of community (PSC) and Big Five personality traits as well as absences from school. Based on samples of 646 high school students and 355 undergraduate college students, PSC was significantly related to Extraversion, Agreeableness, Conscientiousness, and Neuroticism in both samples and to Openness and Absences in the high school sample. Results of stepwise multiple regression analyses showed that the Big Five variables accounted for 25% of the variance in PSC for the high school sample and 21% for the college sample. Openness, PSC, and Neuroticism significantly entered a regression equation to predict Absences. These findings indicate substantial overlap between PSC and Big Five personality traits, raising the question of whether there are any community‐level effects for PSC above and beyond personality. Our results are discussed in terms of consistency with sense of community definitions, person‐environment issues, and directions for future research. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 531–541, 2003.
Community violence exposure and delinquent behaviors among youth: The moderating role of coping
Authors: Rosario Margaret , Salzinger Suzanne , Feldman Richard S. , Ng‐Mak Daisy S.
Published: July 2003

This study examines the moderating roles of guardian and peer support and behavioral coping strategies on the relations between youths' community violence exposure and their delinquent behavior. A sample of 667 public school sixth‐graders in a large inner‐city school district, and their parents or guardians, were interviewed to assess youths' recent exposure to community violence, their delinquent behavior, and proposed moderating variables. Support from guardians buffered the relation between girls' victimization by community violence and delinquency. Support from peers buffered the effects of witnessing community violence on delinquent behavior of boys, but it amplified the effects of victimization for both girls and boys. Avoidant coping behavior buffered the effect of victimization on delinquency for boys but unexpectedly amplified the effect of witnessing violence on delinquency for girls. For both genders, confrontational coping strategies amplified the impact of victimization on delinquency and, for boys only, amplified the impact of witnessing violence as well. Controls were imposed for variables expected to influence the relation between exposure and delinquency, such as ethnicity, family violence, delinquent behavior of friends, and recruitment cohort. Suggestions for future research and implications for intervention are discussed. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 489–512, 2003.
Deacidification of clarified passion fruit juice using different configurations of electrodialysis
Authors: Vera Edwin , Ruales Jenny , Dornier Manuel , Sandeaux Jacqueline , Sandeaux Roger , Pourcelly Gérald
Published: July 2003

The deacidification of clarified passion fruit juice (P edulis v flavicarpa) was investigated using the electrodialysis process (ED). Different stack configurations like conventional electrodialysis (ED2C), three compartments electrodialysis (ED3C) and electrodialysis with bipolar membranes (EDBM3C, EDBM2C) were tested. The conventional electrodialysis did not allow the deacidification of the clarified juice, whilst with the other configurations the pH of juice was increased from 2.9 (initial value) to 4.0 (target level). The ED performances were evaluated as a function of the nature of the anion exchange membrane (AEM), flow rate and current density. The physico‐chemical and sensorial properties of the deacidified juices were similar : the titrable acidity was reduced from 4.3 to 1.14% w/w, the dry soluble extract varied from 13.2 to 11% w/w, the anion concentration was significantly decreased (60% of organic and 85% of inorganic anions were eliminated), the cation concentration remained inchanged, except for the sodium concentration that increased by using ED3C and EDBM3C configurations. The aroma of the passion fruit juice was preserved after treatment whatever the ED configuration used. The EDBM2C configuration deserves a special attention because the consumption of chemicals is totally eliminated and a valuable solution of citric acid with 89% of purity can be produced. Copyright © 2003 Society of Chemical Industry
De‐hairing activity of extracellular proteases produced by keratinolytic bacteria
Authors: Riffel Alessandro , Ortolan Silvia , Brandelli Adriano
Published: July 2003

The depilatory activity of keratinolytic bacteria was investigated. Three keratinolytic bacteria isolated from feather waste were tested for their ability to grow in mineral medium containing bovine hair as sole carbon, nitrogen and energy source. The strains kr2, kr6 and kr10 grew well on bovine hair, producing proteolytic activity as judged by assay with azokeratin as substrate. The proteolytic enzymes from all three strains showed similar pH and temperature optima. Strain kr2 showed mainly serine‐type protease activity, whereas kr6 and kr10 enzymes showed metalloprotease characteristics. The culture supernatants were used as crude enzyme preparations for depilatory studies on bovine pelts. All three strains were efficacious in promoting de‐hairing. Microscopic analysis revealed that the epidermis was completely removed and the absence of hair in follicles was observed. Proteases of keratinolytic bacteria were efficient in promoting depilation of bovine pelts. Enzymatic de‐hairing represents a suitable alternative to the conventional tannery process, with the benefit of avoiding environmental pollution. Copyright © 2003 Society of Chemical Industry
Start‐up and recovery of a biogas‐reactor using a hierarchical neural network‐based control tool
Authors: Holubar Peter , Zani Loredana , Hager Michael , Fröschl Walter , Radak Zorana , Braun Rudolf
Published: July 2003

Due to its intricate internal biological structure the process of anaerobic digestion is difficult to control. The aim of any applied process control is to maximize methane production and minimize the chemical oxygen demand of the effluent and surplus sludge production. Of special interest is the start‐up and adaptation phase of the bioreactor and the recovery of the biocoenose after a toxic event. It is shown that the anaerobic digestion of surplus sludge can be effectively modeled by means of a hierarchical system of neural networks and a prediction of biogas production and composition can be made several time‐steps in advance. Thus it was possible to optimally control the loading rate during the start‐up of a non‐adapted system and to recover an anaerobic reactor after a period of heavy organic overload. During the controlled period an optimal feeding profile that allowed a minimum loading rate of 6 kg COD m−3 d−1 to be maintained was found. Maximum loading rates higher than 12 kg COD m−3 d−1 were often reached without destabilizing the system. The control strategy resulted simultaneously in a high level of gas production of about 3 m3biogas m−3reactor and a methane content in the biogas of about 70%. To visualize the effects of the control strategy on the reactor's operational space the data were processed using a data‐mining program based on Kohonen Self‐Organizing Maps. Copyright © 2003 Society of Chemical Industry
Microbial desulfurization of modeland straight‐run diesel oils
Authors: Mingfang Luo , Zhongxuan Gou , Jianmin Xing , Huizhou Liu , Jiayong Chen
Published: July 2003

The desulfurization kinetics of Nocardia globerula R‐9 was investigated initially in a model system consisting of dibenzothiophene (DBT) dissolved in dodecane. The ability to desulfurize straight‐run diesel oil by resting cells of this strain was also evaluated. The course of desulfurization of DBT in dodecane could be represented by the Michaelis–Menten equation. The desulfurization of DBT and 4,6‐dimethyl dibenzothiophene (4,6‐DMDBT) in a mixture of the two proceeded simultaneously without preference for either of them. The sulfur content of the straight‐run diesel oil could be reduced from 1807 to 741 mg dm−3 by treatment with resting cells of this strain, at a mean rate of 5.1 mmol sulfur kg−1 h−1. This showed that Nocardia globerula R‐9 could be a potential bacterium for reducing the sulfur content of petroleum products. Copyright © 2003 Society of Chemical Industry
A kinetic model for enzymatic reactions in reverse micellar systems involving water‐insoluble substrates and enzyme activators
Authors: Hayashi Y , Talukder MMR , Takeyama T , Wu JC , Kawanishi T , Shimizu N
Published: July 2003

The activity of Chromobacterium viscosum lipase (glycerol‐ester hydrolase, EC 3.1.1.3) entrapped in AOT/isooctane reverse micelles was significantly increased by the addition of short chain polyethylene glycols (PEGs) or methoxypolyethylene glycols (MPEGs) for the hydrolysis of olive oil. To understand enzyme activity in the presence of PEG 400 or MPEG 550 molecules, a kinetic model was proposed. The validity of this model was verified by experimental data on the lipase‐catalyzed hydrolysis of olive oil in AOT/isooctane reverse micellar systems, in which PEG 400 or MPEG 550 had been added. The large value of the equilibrium constant (kD) for enzyme activation indicated that the affinity between C viscosum lipase and PEG 400 or MPEG 550 molecules was very strong. The Michaelis constant (Km) predicted by the proposed model explained enzymatic reactions more exactly than that by the previously published model. Copyright © 2003 Society of Chemical Industry
Photocatalytic and photochemical degradation of aniline using concentrated solar radiation
Authors: Kamble Sanjay P , Sawant Sudhir B , Schouten Jaap C , Pangarkar Vishwas G
Published: July 2003

The photocatalytic and photochemical degradations (PCD) of aniline using concentrated solar radiation were studied. The photochemical reaction takes place on the surface of the catalyst material. Therefore, the adsorption behavior of aniline on the catalyst was also studied. The rates of aniline degradation in the case of the photocatalytic process were compared with the photochemical method. The effects of the presence of anions and cations, which are commonly present in industrial wastewaters, are reported. A plausible explanation for the anomalous behavior of HCO3− and CO32− is given. The effect of pH on the PCD of aniline was also studied. Copyright © 2003 Society of Chemical Industry
Characterization of an organic filter medium for the biofiltration treatment of air contaminated with 1,2‐dichlorobenzene
Authors: Coutu Catherine , Martineau Geneviève , Guy Christophe , Samson Réjean
Published: July 2003

Laboratory experiments were conducted to determine the potential for removing 1,2‐dichlorobenzene (1,2‐DCB) in gaseous phase by biofiltration. Experiments were carried out over 8 months in a steel tank (0.45 m3) using an organic filter medium composed of peat, maple wood chips, chicken manure and 1,2‐DCB‐contaminated soil. During the first 6 months, the biofilter was operated without injecting 1,2‐DCB in order to characterize the physicochemical, mechanical and microbiological properties of the filter bed. The results revealed that it is an excellent medium for both microbial development (up to 109 cells $\hbox{g}^{-1}_{\rm dry\ soil}$ for heterotrophic bacteria) and long‐term stability with a limited drop of pressure (30 cm of water) and no clogging. Over the final 2 months, the biofilter treated air laden with 1,2‐DCB (0.30 and 0.75 g m−3) and the maximum elimination capacity reached was 9 g m−3 h−1 (inlet load of 13 g m−3 h−1), which represented 69% efficiency. Elimination performance was strongly dependent upon inlet concentration, sorption/desorption and biodegradation phenomena occurring in the filter medium. Sorption/desorption and biodegradation mechanisms during the start‐up period were characterized using the elimination efficiency (%). At the beginning of the 1,2‐DCB injection, the microorganisms were strongly impacted and sorption/desorption phenomena prevailed. With the decrease of the inlet concentration, biodegradation progressively increased to become the most important mechanism. It was concluded that biofiltration possesses an excellent potential for treating volatile chlorinated benzene, known to be recalcitrant to biodegradation. Copyright © 2003 Society of Chemical Industry
Electrolytic removal of hexavalent chromium from aqueous solutions
Authors: Chaudhary Abdul J , Goswami Nimai C , Grimes Susan M
Published: July 2003

The removal of hexavalent chromium from a synthetic solution and from an industrial sample by electrolysis using stainless steel plate and titanium mesh cathodes is studied. It is found that the process proceeds in two steps: (1) electroreduction of hexavalent chromium to trivalent chromium in highly acidic medium and (2) electrochemical precipitation of trivalent chromium in an alkaline medium. A comparative study of electroreduction, electrochemical reduction and chemical reduction of hexavalent chromium is carried out and the electroreduction process is shown to be a clean technique. It is concluded that, in the absence of addition of any chemical as reducing agent, the Cr(III) solution formed on the reduction of Cr(VI) can be recycled in other industrial processes. Copyright © 2003 Society of Chemical Industry
Production of syngas for the reduction of sulfur dioxide by methane via a direct RF plasmalysis process
Authors: Tsai Cheng‐Hsien , Wang Ya‐Fen , Huang Yuh‐Jeen , Chang Chia‐Yuan
Published: July 2003

The traditional process for the reduction of SO2 by CH4 usually leads to enrichment of the effluents with H2S and CO2. In this study, a radio‐frequency (RF) plasma system was applied to generate useful byproduct: syngas (H2 and CO) at room temperature. Experimental results indicate that the H2/CO ratio increased with the elevation of inlet [CH4]/[SO2] ratio (R), or the decrease of applied power (E) or operational pressure (P). H2/CO values ranged from 1.34 to 4.28 and reached 2.09 and 1.95 for E = 90 W and 120 W, respectively, at R = 1 and P = 4000 N m−2. At first the selectivity to CO increased with the elevation of R or E, while the selectivity to H2 was only decreased at R > 2 whatever the power that was supplied. However, at R = 2, optimum selectivities of H2 and CO, and decomposition efficiencies of CH4 and SO2, were achieved. The decomposition efficiencies and product components strongly depend on E or R. CH4 is more easily decomposed than SO2 and yields mainly syngas, with traces of CO2, C2H2, and C2H4. In addition, sulfur‐containing compounds including major amounts of CS2, elemental sulfur and minor amounts of COS, but no toxic H2S, were observed. The formation pathways of syngas are also proposed to provide useful information to gain insight into the CH4 conversion in the RF plasma. Copyright © 2003 Society of Chemical Industry
Immobilization of β‐amylase using polyacrylamide polymer derivatives
Authors: Atia KS , Ismail SA , Dessouki AM
Published: July 2003

Barley β‐amlyase was immobilized on two polymeric materials; poly(acrylamide–acrylic acid) resin [P(AM‐AAc)] and poly(acrylamide–acrylic acid–diallylamine–HCl) resin [P(P(AM‐AAc‐DAA‐HCl) using two different methods: covalent and cross‐linking immobilization. Thionyl chloride, used to activate the polymers for covalent immobilization, has the advantage that it is able to react with a number of surface groups of protein under very mild conditions. Cross‐linking with glutaraldehyde gave a higher coupling yield (approximately 70%) than covalent immobilization (approximately 20%). The activity and stability of the resulting biopolymers have been compared with those of free β‐amylase. The specific activity of the immobilized enzyme was significantly influenced by the amount of enzyme loaded onto the polymers, the optimal level being 3.5 mg g−1 polymer. It was found that the immobilized β‐amylase stored at 4°C retained approximately 90% of its original activity after 30 days, whereas free β‐amylase stored in solution at 4°C retained only 47% of its activity after same period. The difference in long term stability was more significant when the enzyme was stored at room temperature; the immobilized enzyme maintained 40% of its activity after 30 days, whereas the residual activity of free enzyme was only 10%. Copyright © 2003 Society of Chemical Industry
Biotechnological production of lactic acid integrated with potato wastewater treatment by Rhizopus arrhizus
Authors: Huang Li Ping , Jin Bo , Lant Paul , Zhou Jiti
Published: July 2003

This paper describes a feasibility study of a for lactic acid production integrated with are treatment of wastewater from an industrial starch plant. Rhizopus oryzae two strains, Rhizopus arrhizus and Rhizopus oligosporus were tested with respect to their capability to carry out simultaneous saccharification and fermentation to lactic acid using potato wastewater. Rhizopus arrhizus DAR 36017 was identified as a suitable strain that demonstrated a high capacity for starch saccharification and lactic acid synthesis. The optimal conditions, in terms of pH, temperature and starch concentration, for lactic acid production were determined. The selected fungal strain grew well in a pH range from 3.0 to 7.0. The addition of CaCO310 g dm−3 maintained the pH at 5.0–6.0 and significantly enhanced lactic acid production. Kinetic study revealed that almost complete starch saccharification and a lactic acid yield of 450g kg−1 could be achieved in 20 h and 28 h cultivation, respectively. The maximum lactic acid production 21 g dm−3 and mycelial biomass (1.7 g dm−3) were obtained at 30 °C. Besides the multiple bioproducts, total removal of suspended solids and 90% reduction of COD were achieved in a single no‐aseptic operation. Copyright © 2003 Society of Chemical Industry
Differentiation and functions of osteoclasts and odontoclasts in mineralized tissue resorption
Authors: Sasaki Takahisa
Published: July 2003

The differentiation and functions of osteoclasts (OC) are regulated by osteoblast‐derived factors such as receptor activator of NFKB ligand (RANKL) that stimulates OC formation, and a novel secreted member of the TNF receptor superfamily, osteoprotegerin (OPG), that negatively regulates osteoclastogenesis. In examination of the preosteoclast (pOC) culture, pOCs formed without any additives expressed tartrate‐resistant acid phosphatase (TRAP), but showed little resorptive activity. pOC treated with RANKL became TRAP‐positive OC, which expressed intense vacuolar‐type H+‐ATPase and exhibited prominent resorptive activity. Such effects of RANKL on pOC were completely inhibited by addition of OPG. OPG inhibited ruffled border formation in mature OC and reduced their resorptive activity, and also induced apoptosis of some OC. Although OPG administration significantly reduced trabecular bone loss in the femurs of ovariectomized (OVX) mice, the number of TRAP‐positive OC in OPG‐administered OVX mice was not significantly decreased. Rather, OPG administration caused the disappearance of ruffled borders and decreased H+‐ATPase expression in most OC. OPG deficiency causes severe osteoporosis. We also examined RANKL localization and OC induction in periodontal ligament (PDL) during experimental movement of incisors in OPG‐deficient mice. Compared to wild‐type OPG (+/+) littermates, after force application, TRAP‐positive OC were markedly increased in the PDL and alveolar bone was severely destroyed in OPG‐deficient mice. In both wild‐type and OPG‐deficient mice, RANKL expression in osteoblasts and fibroblasts became stronger by force application. These in vitro and in vivo studies suggest that RANKL and OPG are important regulators of not only the terminal differentiation of OC but also their resorptive function. To determine resorptive functions of OC, we further examined the effects of specific inhibitors of H+‐ATPase, bafilomycin A1, and lysosomal cysteine proteinases (cathepsins), E‐64, on the ultrastructure, expression of these enzymes and resorptive functions of cultured OC. In bafilomycin A1‐treated cultures, OC lacked ruffled borders, and H+‐ATPase expression and resorptive activity were significantly diminished. E‐64 treatment did not affect the ultrastructure and the expression of enzyme molecules in OC, but significantly reduced resorption lacuna formation, by inhibition of cathepsin activity. Lastly, we examined the expression of H+‐ATPase, cathepsin K, and matrix metalloproteinase‐9 in odontoclasts (OdC) during physiological root resorption in human deciduous teeth, and found that there were no differences in the expression of these molecules between OC and OdC. RANKL was also detected in stromal cells located on resorbing dentine surfaces. This suggests that there is a common mechanism in cellular resorption of mineralized tissues such as bone and teeth. Microsc. Res. Tech. 61:483–495, 2003. © 2003 Wiley‐Liss, Inc.
Intracellular membrane trafficking in bone resorbing osteoclasts
Authors: Mulari Mika , Vääräniemi Jukka , Väänänen H. Kalervo
Published: July 2003

There is ample evidence now that the two major events in bone resorption, namely dissolution of hydroxyapatite and degradation of the organic matrix, are performed by osteoclasts. The resorption cycle involves several specific cellular activities, where intracellular vesicular trafficking plays a crucial role. Although details of these processes started to open up only recently, it is clear that vesicular trafficking is needed in several specific steps of osteoclast functioning. Several plasma membrane domains are formed during the polarization of the resorbing cells. Multinucleated osteoclasts create a tight sealing to the extracellular matrix as a first indicator of their resorption activity. Initial steps of the sealing zone formation are αvβ3‐integrin mediated, but the final molecular interaction(s) between the plasma membrane and mineralized bone matrix is still unknown. A large number of acidic intracellular vesicles then fuse with the bone‐facing plasma membrane to form a ruffled border membrane, which is the actual resorbing organelle. The formation of a ruffled border is regulated by a small GTP‐binding protein, rab7, which indicates the late endosomal character of the ruffled border membrane. Details of specific membrane transport processes in the osteoclasts, e.g., the formation of the sealing zone and transcytosis of bone degradation products from the resorption lacuna to the functional secretory domain remain to be clarified. It is tempting to speculate that specific features of vesicular trafficking may offer several potential new targets for drug therapy of bone diseases. Microsc. Res. Tech. 61:496–503, 2003. © 2003 Wiley‐Liss, Inc.
Matrix metalloproteinases (MMP) and cathepsin K contribute differently to osteoclastic activities
Authors: Delaissé Jean‐Marie , Andersen Thomas L. , Engsig Michael T. , Henriksen Kim , Troen Tine , Blavier Laurence
Published: July 2003

The best established proteolytic event of osteoclasts is bone matrix solubilization by the cysteine proteinase cathepsin K. Here, however, we draw the attention on osteoclastic activities depending on matrix metalloproteinases (MMPs). We discuss the observations supporting that MMPs contribute significantly to bone matrix solubilization in specific areas of the skeleton and in some developmental and pathological situations. Our discussion takes into account (1) the characteristics of the bone remodeling persisting in the absence of cathepsin K, (2) the ultrastructure of the resorption zone in response to inactivation of MMPs and of cathepsin K in different bone types, (3) bone resorption levels in MMP knockout mice compared to wild‐type mice, (4) the identification of MMPs in osteoclasts and surrounding cells, and (5) the effect of different bone pathologies on the serum concentrations of specific collagen fragments believed to discriminate between cathepsin K and MMP cleavage. Next, we provide evidence that MMPs are very critical for osteoclast migration, thereby controlling also the cell‐matrix interactions required for cell attachment/detachment. The evidence supporting this role is based on a model of osteoclast recruitment in primitive long bones, an assay of osteoclast invasion through collagen gel, and the effect of proteinase inhibitors/knockouts in these models. Furthermore, we mention observations indicating a role of MMPs in initiation of bone resorption. Finally, we emphasize the many distinct ways MMPs may alter focally the extracellular environment thereby regulating the osteoclast behavior. Although the understanding of MMPs in osteoclast biology is rapidly expanding, it is suspected that important roles remain to be discovered. Microsc. Res. Tech. 61:504–513, 2003. © 2003 Wiley‐Liss, Inc.
Osteoclast diseases
Authors: Helfrich Miep H.
Published: July 2003

Osteoclasts are the only cells capable of resorbing mineralised bone, dentine and cartilage. Osteoclasts act in close concert with bone forming osteoblasts to model the skeleton during embryogenesis and to remodel it during later life. A number of inherited human conditions are known that are primarily caused by a defect in osteoclasts. Most of these are rare monogenic disorders, but others, such as the more common Paget's disease, are complex diseases, where genetic and environmental factors combine to result in the abnormal osteoclast phenotype. Where the genetic defect gives rise to ineffective osteoclasts, such as in osteopetrosis and pycnodysostosis, the result is the presence of too much bone. However, the phenotype in many osteoclast diseases is a combination of osteosclerosis with osteolytic lesions. In such conditions, the primary defect is hyperactivity of osteoclasts, compensated by a secondary increase in osteoblast activity. Rapid progress has been made in recent years in the identification of the causative genes and in the understanding of the biological role of the proteins encoded. This review discusses the known osteoclast diseases with particular emphasis on the genetic causes and the resulting osteoclast phenotype. These human diseases highlight the critical importance of specific proteins or signalling pathways in osteoclasts. Microsc. Res. Tech. 61:514–532, 2003. © 2003 Wiley‐Liss, Inc.
Osteoclastic bone resorption around intraosseous screws in rat and pig mandibles
Authors: Schulten Alcuin J.M. , Zimmermann Corinna E. , Glowacki Julie
Published: July 2003

This report describes osteoclastic bone resorption around intraosseous fixation screws in rat and pig mandibles. These screws supported distraction devices and provided for neutral fixation following the distraction period. Progressive clinical instability of bicortical screws and radiographic and histologic evidence of osseous resorption were frequent findings. In rats, clinical evaluation revealed screw loss and/or loosening in 50% of the rats between 11 and 30 days of neutral fixation. Radiographic signs of resorption were apparent around 60% of the screws that were in place at the end of the observation period. The total rate of resorption or loss was 64 of 80 screws (80%). Histologic examination showed partial or extensive osteolysis around the screw holes in 87% of screws that were clinically fixed in the bone at sacrifice. In histologic sections of porcine specimens, osseous resorption around identifiable screw holes was present in 75% of the cases, and showed progressive increase in resorption with time. Osteoclastic resorption was common around bicortical screws that were evaluated after they had served for osseous stability. Microsc. Res. Tech. 61:533–539, 2003. © 2003 Wiley‐Liss, Inc.