bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensorineural deafness, abnormal genitalia, synostosis of metacarpals and metatarsals 4 and 5, and mental retardation: Description of a second patient and exclusion of HOXD13
Authors: Mendioroz Jacobo , Fernández‐Toral Joaquín , Suárez Etelvina , López‐Grondona Fermina , Kjaer Klaus W. , Bermejo Eva , Martínez‐Frías María Luisa
Published: May 2005

In 1988 Pfeiffer and Kapferer reported on a patient with sensorineural deafness, psychomotor delay, hypospadias, cerebral manifestations, and bilateral synostosis of the 4th and 5th metacarpals and metatarsals. Synostosis of the 4th and 5th metacarpals and metatarsals is a very rare defect that has been described as an isolated Mendelian defect, as part of multiple congenital anomaly (MCA) patterns, and in different syndromes. Among a total of 2,023,155 liveborn infants in the Spanish Collaborative Study of Congenital Malformations (ECEMC), we observed only two cases with this type of metacarpal fusion, for a frequency of 1/1,011,577. One had the isolated defect, and the other one that we are describing here, had an MCA pattern similar to that described by Pfeiffer and Kapferer [1988]. We tested HOXD13 but did not find any mutations in exons and intron–exon boundaries. To our knowledge this case is the second one reported with this syndrome. © 2005 Wiley‐Liss, Inc.
Tumor risk in Beckwith–Wiedemann syndrome: A review and meta‐analysis
Authors: Rump P. , Zeegers M.P.A. , van Essen A.J.
Published: May 2005

Beckwith–Wiedemann syndrome (BWS) is an overgrowth syndrome associated with macroglossia, abdominal wall defects, ear anomalies, and an increased risk for embryonic tumors. Reported tumor risk estimates vary between 4% and 21%. It has been hypothesized that tumor predisposition in BWS is related to the imprinting status of the H19 and LIT1 genes on chromosome 11p15. A loss of imprinting (LOI) of H19 implies a higher tumor risk. However, a systematic analysis of available data is lacking. Therefore, we performed a review and meta‐analysis of reported associations between the imprinting status of the LIT1 and H19 genes and the risk for tumor development in BWS. Five publications suitable for meta‐analysis were identified by electronic database searches. Sufficient data were available for 402 out of 520 patients. Patients were divided into four groups based on the imprinting status of H19 and LIT1: group I with LOI of LIT1 (45%); group II with LOI of H19 (9%); group III with LOI of LIT1 and LOI of H19 (21%); and group IV with normal imprinting patterns (26%). Differences in tumor risk between groups were studied with random effects meta‐analysis. Tumors occurred in 55 patients. The odds of tumor development was significantly lower in group I when compared to group II (OR = 0.06; 95% CI: 0.02–0.21) and group III (OR = 0.12; 95% CI: 0.04–0.37). Tumor risk did not differ significantly between groups II and III (OR = 1.40; 95% CI: 0.56–3.50). Compared to group IV, tumor risk was significantly lower in group I (OR = 0.33; 95% CI: 0.12–0.87) and higher in groups II (OR = 4.0; 95% CI: 1.5–10.4) and III (OR = 2.6; 95% CI: 1.2–5.7). Tumor incidence rate for group IV was 10.6% (95% CI: 3.6–17.7). Calculated absolute risks were 3% for group I, 43% for group II, and 28% for group III, respectively. No Wilms tumor was seen in group I. In total, other tumors were seen with comparable frequencies in groups I–III. The results show a strong association between a LOI of H19 and especially Wilms tumor development in BWS. © 2005 Wiley‐Liss, Inc.
Autosomal dominant inheritance of spondyloenchondrodysplasia
Authors: Bhargava R. , Leonard N.J. , Chan A.K.J. , Spranger J.
Published: May 2005

Spondyloenchondrodysplasia comprises generalized enchondromatosis with platyspondyly and is thought to be inherited as an autosomal recessive condition. A mother and son are reported with typical features of spondyloenchondrodysplasia. Their similar radiographic and MRI findings are presented. The radiologic appearance of the spine changed over time, illustrating the evolving phenotype of this condition. Transmission from mother to son suggests that dominant pattern of inheritance is possible. A classification of the enchondromatoses is discussed. © 2005 Wiley‐Liss, Inc.
EMX2‐independent familial schizencephaly: Clinical and genetic analyses
Authors: Tietjen Ian , Erdogan Füsun , Currier Sophie , Apse Kira , Chang Bernard S. , Hill R. Sean , Lee Christine K. , Walsh Christopher A.
Published: May 2005

Schizencephaly is a human brain malformation distinguished by full‐thickness unilateral or bilateral clefts through the neocortex. Heterozygous mutations in the EMX2 locus are reported to give rise to schizencephaly. However, the comprehensive identification of causative genetic loci is precluded by a lack of large pedigrees and genome‐wide linkage analyses. We present here a large Turkish pedigree with three individuals with schizencephaly. The similarity of clinical signs in affected individuals strongly suggests an underlying genetic cause; however, genome‐wide linkage analysis rules out EMX2 linkage and instead suggests additional candidate loci. These results indicate that genetic forms of schizencephaly are likely to be heterogeneous. © 2005 Wiley‐Liss, Inc.
Are the betaine‐homocysteine methyltransferase (BHMT and BHMT2) genes risk factors for spina bifida and orofacial clefts?
Authors: Zhu Huiping , Curry Stacey , Wen Shu , Wicker Ned J. , Shaw Gary M. , Lammer Edward J. , Yang Wei , Jafarov Toghrul , Finnell Richard H.
Published: May 2005

Abnormalities in folate and/or homocysteine metabolism may adversely influence embryonic development, leading to the birth of infants with a variety of congenital malformations, including neural tube defects (NTDs) and craniofacial abnormalities. Based upon suggestive evidence that periconceptional folic acid supplementation is effective in preventing a significant proportion of the aforementioned birth defects, genetic variation in the folate biosynthetic pathways may influence the infant's susceptibility to these birth defects. The goal of our study was to investigate sequence variations in the betaine‐homocysteine methyltransferase (BHMT) and betaine‐homocysteine methyltransferase (BHMT2) genes as modifiers of risk of spina bifida, cleft palate, and cleft lip and palate. The results of this study indicated that individuals homozygous for the single nucleotide polymorphism R239Q in BHMT did not have elevated risks for spina bifida. Genotype frequencies for the BHMT2 rs626105 polymorphism also did not reveal any elevated risks for spina bifida, and only a modest, imprecise elevation of risk for orofacial clefts. The results of these experiments suggest that variants of the BHMT/BHMT2 genes in infants do not substantially contribute to the risk of spina bifida or orofacial clefts in our study population. © 2005 Wiley‐Liss, Inc.
Novel mutation in DGUOK in hepatocerebral mitochondrial DNA depletion syndrome associated with cystathioninuria
Authors: Tadiboyina Venu T. , Rupar Anthony , Atkison Paul , Feigenbaum Annette , Kronick Jonathan , Wang Jian , Hegele Robert A.
Published: May 2005

Mitochondrial depletion syndrome (MDS) refers to a heterogeneous group of mitochondrial disorders characterized by a reduction of the mtDNA copy number in affected tissues. Mutations in DGUOK encoding deoxyguanosine kinase (MIM 601465) cause the hepatocerebral form of MDS (MIM 251880). Cystathioninuria (MIM 219500) can result from mutations in CTH encoding cystathionine gamma lyase (MIM 607657) or can be a secondary finding in several diverse clinical conditions. We present three patients from two apparently unrelated old colony Mennonite families, each of whom had the hepatocerebral form of MDS together with cystathioninuria. Each affected child was homozygous for the novel DGUOK p.D255Y mutation, but had no CTH mutation, indicating that the hepatocerebral form of MDS might be associated with secondary cystathioninuria. © 2005 Wiley‐Liss, Inc.
Mesiodistal tooth crown dimensions of the primary dentition: A worldwide survey
Authors: Harris Edward F. , Lease Loren R.
Published: May 2005

This analysis reports on a spatial‐temporal survey of published studies of primary tooth crown dimensions in humans (80 samples). Mesiodistal data are analyzed for the 10 tooth crown dimensions. The purpose was to evaluate the numerous case reports (descriptive analyses of single samples) in the literature in order to assess patterning of variation 1) in tooth size, 2) among tooth types, 3) across sexes, 4) with space (historical affinity), and 5) with time. Sexual dimorphism is low in the primary dentition, averaging 2% across all 10 tooth types. All size distributions of the samples are positively skewed because of megadont native Australians. Europeans, who are most frequently represented in the literature, have the smallest tooth crowns of any continental grouping assessed. The method by Darroch Mosimann ([1985] Biometrika 72:241–252) of reducing size effects was used, basically standardizing the data variable‐wise, and then ordinating groups on their factor scores. Principal components analysis produced just two canonical axes: overall size (68%) and a front‐back (i1‐i2‐c vs. m1‐m2) polarity (11%), based on the intergroup (not ontogenetic) covariance matrix. This second component discriminates between groups with relatively large anterior teeth (Europeans) and those where relatively more tooth substance is apportioned to the molars (Africans and Asians). Size differences predominate over shape between sexes from the same groups. Europeans have small teeth with comparatively large anterior dimensions. Asian and sub‐Saharan African samples share features of average crown size but large cheek teeth. Indian and European samples show considerable overlap on both canonical axes, with average size overall but comparatively large anterior teeth. The few Amerindian samples are too variable to characterize. Based on comparisons of archaeological and living samples, tooth size reductions are documented here for Europe, India, and the Near East compared to tooth sizes of Neolithic and Mesolithic samples. The temporal changes parallel those documented elsewhere for the permanent dentition. The biological and anthropological relevance of these distributions is discussed. Am J Phys Anthropol, 2005. © 2005 Wiley‐Liss, Inc.
Combining process and property models: Development of novel reaction strategies for high‐solids, low‐viscosity latices
Authors: do Amaral Marcelo , van Es Steven , Asua José M.
Published: May 2005

Multiple strategies for the synthesis of high‐solids, low‐viscosity latices have been established in modern polymer industry. The basic principle supporting these strategies is the polydispersity of the particle size distribution. However, polymerization procedures are often based on experience, tacit knowledge acquired with time and repetitive trial‐and‐error procedures. Recently, a novel coupled polymerization–viscosity model has been proposed. The model aids screening of potential polymerization strategies. This work presents use of the model as a powerful tool to design new strategies for obtaining highly concentrated aqueous polymer dispersions. By incorporating some simplifying assumptions into the coupled model, the feasibility for synthesizing high‐solids latex with low viscosity using novel polymerization strategies was assessed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 733–744, 2005
Synthesis of removable and repositionable water‐borne pressure‐sensitive adhesive acrylics
Authors: Czech Zbigniew
Published: May 2005

This publication shows the synthesis of the water‐borne removable pressure‐sensitive adhesive (PSA) based on acrylates and the influence of parameters such as internal emulsifiers on peel adhesion on steel and also the influence of N‐methylol acrylamide and plasticizers on peel adhesion on glass, poly(vinyl chloride), and polypropylene during aging time. Removable and repositionable pressure‐sensitive adhesives based on acrylic polymers are used for the production of removable memo notes, paper and foil labels, double‐sided tapes, carrier‐free tapes to protective films, and manufacturing aids. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 886–892, 2005
Thermal degradation kinetics of polyesters containing mesogenic aromatic diols
Authors: Mule S. A. , Ghadage R. S. , Jacob N. E. , Rajan C. R. , Ponrathnam S.
Published: May 2005

A series of polyesters were synthesized by reacting structurally differing aromatic diols with either saturated (flexible) or unsaturated (rigid) dicarboxylic acid halide by a stirred interfacial polycondensation technique. Thermal degradation kinetics of these polyesters were investigated by applying Coats–Redfern and Horowitz–Metzger nonisothermal procedures. The dynamic thermogravimetry experiments were conducted in nitrogen to obtain differential thermogravimetric plots. Thermal stability of these polyesters was discussed on the basis of semiquantitative methods such as differential procedural decomposition temperature, integral procedural decomposition temperature, and fraction decomposition temperature (e.g., 10% DT). Degradation proceeded in multiple stages. The thermal degradation patterns and activation energies in these stages were discussed in relation to central bridging moieties of aromatic diol. The activation energies of these polyesters were found to be in the range of 100 to 200 kJ/mol. The effect of spacer type on activation energy was also reported. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 784–792, 2005
Dioxazoline coupling of maleic anhydride modified polyethylene
Authors: Colbeaux Aimeline , Fenouillot Françoise , Gerard Jean‐François , Taha Mohamed , Wautier Henri
Published: May 2005

Maleic anhydride modified polyethylene (PEgMA) coupling reactions were realized using a dioxazoline coupling agent, (1,3‐phenylene)‐bis(2‐oxazoline), in an internal mixer. In preliminary studies and in model reactions, it was shown that anhydride/oxazoline reactions were very slow or nonexistent compared to acid/oxazoline reactions. The main observed coupling is due to acids resulting from anhydride hydration. In a second part, the coupling reactions were preceded by an anhydride hydration realized by direct injection of different water quantities. In these cases, the couplings were more efficient than when PEgMA were directly used. At high temperature some of the formed succinic acids were dehydrated, leading to the initial succinic anhydrides. The study of the effect of the molar ratio of oxazoline/anhydride on the PEgMA coupling showed that the maximum apparent coupling was obtained when the ratio was 4. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 837–843, 2005
Electron beam irradiation of ethylene‐propylene terpolymer: Evaluation of trimethylol propane trimethacrylate as a crosslink promoter
Authors: Chowdhury Rajesh , Banerji M. S.
Published: May 2005

The effect of electron beam irradiation on ethylene‐propylene terpolymer (EPDM) was investigated. A 50‐part oil‐extended EPDM with high termonomer (ENB) content (iodine number of base polymer) 19, was selected for this study. An increase in irradiation dose from 0 to 200 kGy resulted in increased crosslinking, measured by an increase in gel contents and better swelling resistance. The effect of the multifunctional monomer trimethylol propane trimethacrylate (TMPTMA) as a crosslink promoter was studied using IR spectroscopy. The IR studies revealed enhanced peak absorbances at 1725, 1257, and 1023 cm−1 as a result of the increased concentration of C = O and C‐O‐C groups and reduced absorbance at 1630 cm−1 due decreased concentration of C = C groups with TMPTMA level in the irradiated samples. The presence of TMPTMA increased the level of crosslinking at a given irradiation dose, which was manifested by improvement in tensile properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 968–975, 2005
Evolution in the natural rubber native structure and plasticity retention index from the first tapping of clonal trees
Authors: Bonfils F. , Doumbia A. , Char C. , Beuve J. Sainte
Published: May 2005

This study was carried out with five rubber clones planted in Côte d'Ivoire from the first tapping up to the 18th month of tree tapping (1 tapping/4 days). Changes in the natural rubber native mesostructure (macromolecular structure, macrogel, and microgel) of films prepared from fresh field latex were monitored. At the same time, the evolution of the thermooxidation sensitivity of raw rubber samples [grade 10 technically specified rubber (TSR10)] was also monitored with the plasticity retention index (PRI). The substantial initial macrogel rate (70–86%, depending on the clone) fell during the first 18 months of tree tapping to reach a few percent. However, during the same period, the initially low microgel rate (5–15%) increased and then remain stabilized around 55% rubber. The macromolecular structure [weight‐average molecular weight (Mw) and molar mass distribution (MMD)] also changed after tree opening. Mw increased and stabilized after 7.5 months of tapping. The bimodal MMD primarily involved short chains (molar mass < 400 kg/mol) at the opening of the trees. The TSR10 samples, prepared with latex from virgin trees, showed high PRIs and, therefore, low sensitivity to thermooxidation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 903–909, 2005
Acrylic weak‐base anion exchangers and their behaviors in the retention process of some heavy‐metal cations
Authors: Luca Cornelia , Măruţă Cristina , Bunia Ion , Urmenyi Ana Maria , Sandu Mihaela , Raţă Daniela
Published: May 2005

Two macroporous acrylonitrile/10% vinyl acetate/10% divinylbenzene copolymers as beads were obtained by the aqueous suspension copolymerization of the three comonomers in the presence of toluene as a diluent, which was used in two different amounts. These copolymers were chemically modified by their reactions with ethylenediamine, diethylenetriamine, and triethylenetetramine in the presence of water when the aminolysis–hydrolysis reaction of the nitrile groups and the hydrolysis reaction of the acetate groups occurred. From these reactions, weak‐base anion exchangers with high ion‐exchange capacities, between 1.6 and 2.2 mequiv/mL and 6.5 and 10.5 mequiv/g, were obtained. For these anion exchangers, the behaviors in the retention processes of the Ni(II), Cd(II), and Pb(II) cations were evaluated with the bath method. All the resins exhibited retention properties, but the retained amounts of the metal cations differed as a function of the resin and cation nature. Thus, the resin from the reaction with triethylenetetramine of the copolymer obtained in the presence of a larger amount of toluene could be considered the most suitable sorbent for the three metal cations, especially for Ni(II). Its maximum retention capacity for this cation was 2.67 mequiv/g of dried resin. From the noncompetitive and competitive retentions was observed the following selectivity order: Ni(II) > Cd(II) > Pb(II). The retention took place by the chelating processes between the functional groups with the ligand role, especially free amine groups, and metal cations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 930–938, 2005
Optimization of pulsed electromagnetic field therapy for management of arthritis in rats
Authors: Kumar Venkatachalam Senthil , Kumar Dilly Ashok , Kalaivani Kalyanasundaram , Gangadharan Akkalayi Chandrapuram , Raju K.V.S. Narayana , Thejomoorthy Pammi , Manohar Bhakthavatchalam Murali , Puvanakrishnan Rengarajulu
Published: May 2005

Studies were undertaken to find out the effects of low frequency pulsed electromagnetic field (PEMF) in adjuvant induced arthritis (AIA) in rats, a widely used model for screening potential therapies for rheumatoid arthritis (RA). AIA was induced by an intradermal injection of a suspension of heat killed Mycobacterium tuberculosis (500 μg/0.1 ml) into the right hind paw of male Wistar rats. This resulted in swelling, loss of body weight, increase in paw volume as well as the activity of lysosomal enzymes viz., acid phosphatase, cathepsin D, and β‐glucuronidase and significant radiological and histological changes. PEMF therapy for arthritis involved optimization of three significant factors, viz., frequency, intensity, and duration; and the waveform used is sinusoidal. The use of factorial design in lieu of conventional method resulted in the development of an ideal combination of these factors. PEMF was applied using a Fransleau–Braunbeck coil system. A magnetic field of 5 Hz × 4 μT × 90 min was found to be optimal in lowering the paw edema volume and decreasing the activity of lysosomal enzymes. Soft tissue swelling was shown to be reduced as evidenced by radiology. Histological studies confirmed reduction in inflammatory cells infiltration, hyperplasia, and hypertrophy of cells lining synovial membrane. PEMF was also shown to have a membrane stabilizing action by significantly inhibiting the rate of release of β‐glucuronidase from lysosomal rich and sub‐cellular fractions. The results indicated that PEMF could be developed as a potential therapy in the treatment of arthritis in humans. Bioelectromagnetics 26:431–439, 2005. © 2005 Wiley‐Liss, Inc.
Effects of GSM signals on auditory evoked responses
Authors: Maby E. , Jeannès R. Le Bouquin , Faucon G. , Liégeois‐Chauvel C. , De Sèze R.
Published: May 2005

The article presents a study of the influence of radio frequency (RF) fields emitted by mobile phones on human cerebral activity. Our work was based on the study of Auditory Evoked Potentials (AEPs) recorded on the scalp of healthy humans and epileptic patients. The protocol allowed us to compare AEPs recorded with or without exposure to RFs. To get a reference, a control session was also introduced. In this study, the correlation coefficients computed between AEPs, as well as the correlation coefficients between spectra of AEPs were investigated to detect a possible difference due to RFs. A difference in the correlation coefficients computed in control and experimental sessions was observed, but it was difficult to deduce the effect of RFs on human health. Bioelectromagnetics 26:341–350, 2005. © 2005 Wiley‐Liss, Inc.
Effect of weak, interrupted sinusoidal low frequency magnetic field on neural regeneration in rats: Functional evaluation
Authors: Bervar Marijan
Published: May 2005

A study of the effect of weak, interrupted sinusoidal low frequency magnetic field (ISMF) stimulation on regeneration of the rat sciatic nerve was carried out. In the experiment, 60 Wistar rats were used: 24 rats underwent unilateral sciatic nerve transection injury and immediate surgical nerve repair, 24 rats underwent unilateral sciatic nerve crush injury, and the remaining 12 rats underwent a sham surgery. Half of the animals (n = 12) with either sciatic nerve lesion were randomly chosen and exposed between a pair of Helmholtz coils for 3 weeks post‐injury, 4 h/day, to an interrupted (active period to pause ratio = 1.4 s/0.8 s) sinusoidal 50 Hz magnetic field of 0.5 mT. The other half of the animals (n = 12) and six rats with sham surgery were used for two separate controls. Functional recovery was followed for 6 weeks for the crush injuries and 7½ months for the transection injuries by video assisted footprint analysis in static conditions and quantified using a recently revised static sciatic index (SSI) formula. We ascertained that the magnetic field influence was weak, but certainly detectable in both injury models. The accuracy of ISMF influence detection, determined by the one‐way repeated measures ANOVA test, was better for the crush injury model: F(1, 198) = 9.0144, P = .003, than for the transection injury model: F(1, 198) = 6.4826, P = .012. The Student–Newman–Keuls range test for each response day yielded significant differences (P < .05) between the exposed and control groups early in the beginning of functional recovery and later on from the points adjacent to the beginning of the plateau, or 95% of functional recovery, and the end of observation. These differences probably reflect the ISMF systemic effect on the neuron cell bodies and increased and more efficient reinnervation of the periphery. Bioelectromagnetics 26:351–356, 2005. © 2005 Wiley‐Liss, Inc.
Perception of local DC and AC electric fields in humans
Authors: Chapman C. Elaine , Blondin Jean‐Pierre , Lapierre Anne Marie , Nguyen Duc H. , Forget Robert , Plante Michel , Goulet Daniel
Published: May 2005

The goal of this study was to address some of the factors that contribute to the human ability to detect the presence of weak electric fields generated by direct current (DC) and alternating current (AC) sources. An exposure chamber allowed us to expose a limited surface of the body (forearm and hand) to DC fields of up to 65 kV/m and AC fields up to a maximum of 35 kV/m (frequency 60 Hz). Perception was examined using a staircase procedure and a rating procedure derived from signal detection theory. Sixteen subjects participated in the experiments, and none detected the local DC fields. In contrast, 9/16 subjects were sensitive to local AC electric fields, although detection thresholds (index of sensitivity, d′ = 1.0) were widely variable between subjects. When regional exposure was limited to the dorsal forearm, performance was similar to that seen when the forearm and hand were exposed. In contrast, subjects did not reliably detect the AC electric fields when exposure was limited to the hand (either hairy or glabrous skin), although a minority of subjects (3/9) showed some evidence of detecting fields presented to the glabrous palm. Subjects were unable to detect AC electric fields when the hair was removed from the forearm and hand, suggesting that the evoked sensation is mainly dependent on movement of hair located in the exposed region. Bioelectromagnetics 26:357–366, 2005. © 2005 Wiley‐Liss, Inc.
Controversial cytogenetic observations in mammalian somatic cells exposed to extremely low frequency electromagnetic radiation: A review and future research recommendations
Authors: Vijayalaxmi  , Obe Guenter
Published: May 2005

During the years 1990–2003, a large number of investigations were conducted using animals, cultured rodent and human cells as well as freshly collected human blood lymphocytes to determine the genotoxic potential of exposure to nonionizing radiation emitted from extremely low frequency electromagnetic fields (EMF). Among the 63 peer reviewed scientific reports, the conclusions from 29 studies (46%) did not indicate increased damage to the genetic material, as assessed from DNA strand breaks, incidence of chromosomal aberrations (CA), micronuclei (MN), and sister chromatid exchanges (SCE), in EMF exposed cells as compared with sham exposed and/or unexposed cells, while those from 14 investigations (22%) have suggested an increase in such damage in EMF exposed cells. The observations from 20 other studies (32%) were inconclusive. This study reviews the investigations published in peer reviewed scientific journals during 1990–2003 and attempts to identify probable reason(s) for the conflicting results. Recommendations are made for future research to address some of the controversial observations. Bioelectromagnetics 26:412–430, 2005. © 2005 Wiley‐Liss, Inc.
Influence of pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 rat pheochromocytoma cells
Authors: Zhang Y. , Ding J. , Duan W. , Fan W.
Published: May 2005

The influence of low frequency (50 Hz repetition rate) pulsed electromagnetic field (EMF) on PC12 cell neurite outgrowth in vitro was investigated in this study. We studied the percentage of neurite bearing cells, average length of neurites, and directivity of neurite outgrowth in PC12 cells cultured for 96 h in the presence of nerve growth factor (NGF). PC12 cells were exposed in one incubator to pulsed EMF at 1.36 mT (peak value) generated by a pair of Helmholtz coils, and the control samples were placed in another identical incubator. We found that the pulse duty cycle had significant effect on neurite outgrowth. Low (10%) pulse on‐time significantly inhibited the percentage of neurite bearing cells, but at the same time increased the average length of neurites, while 100% on‐time (DC) had exactly the opposite effects. Furthermore, we found that neurites were prone to extend along the direction of pulsed EMF with 10% pulse on‐time. Our studies show that neurite outgrowth in PC12 cells is sensitive to the pulse duty and this sensitivity was associated with NGF concentration. Bioelectromagnetics 26:406–411, 2005. © 2005 Wiley‐Liss, Inc.
Conformation of gramicidin a in water: Inference from analysis of hydrogen/deuterium exchange behavior by matrix assisted laser desorption ionization mass spectrometry
Authors: Jagannadham M. V. , Nagaraj Ramakrishnan
Published: May 2005

Gramicidin A (the major component of gramicidin D) is a highly hydrophobic peptide with very little solubility in water. Hence, the conformation of this peptide has been extensively investigated in organic solvents and model membranes, but not in water. The peptide adopts a β6.3‐helical conformation in the monomeric and dimeric forms. We have investigated the conformation of gramicidin A in water by monitoring hydrogen–deuterium exchange by matrix‐assisted laser desorption ionization–time‐of‐flight mass spectrometry. Our results indicate that gramicidin A is monomeric and exists in a highly folded conformation. The metal ion bound forms are clearly discernible in the monomers. The presence of the dimeric form is not observed. It is unlikely this is due to the operating conditions or the method used, as both hetero‐ and homodimers in gramicidin D are detected when methanol is used as a solvent. The present study also establishes that the linear gramicidins retain a history of solvent environment when ions are generated by matrix‐assisted laser desorption ionization and analyzed by time‐of‐flight. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 708–713, 2005

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Comparison of acetate and propionate uptake by polyphosphate accumulating organisms and glycogen accumulating organisms
Authors: Oehmen Adrian , Yuan Zhiguo , Blackall Linda L. , Keller Jürg
Published: May 2005

Enhanced biological phosphorus removal (EBPR) performance is directly affected by the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs). This study investigates the effects of carbon source on PAO and GAO metabolism. Enriched PAO and GAO cultures were tested with the two most commonly found volatile fatty acids (VFAs) in wastewater systems, acetate and propionate. Four sequencing batch reactors (SBRs) were operated under similar conditions and influent compositions with either acetate or propionate as the sole carbon source. The stimulus for selection of the PAO and GAO phenotypes was provided only through variation of the phosphorus concentration in the feed. The abundance of PAOs and GAOs was quantified using fluorescence in situ hybridisation (FISH). In the acetate fed PAO and GAO reactors, “Candidatus Accumulibacter phosphatis” (a known PAO) and “Candidatus Competibacter phosphatis” (a known GAO) were present in abundance. A novel GAO, likely belonging to the group of Alphaproteobacteria, was found to dominate the propionate fed GAO reactor. The results clearly show that there are some very distinctive differences between PAOs and GAOs in their ability to take up acetate and propionate. PAOs enriched with acetate as the sole carbon source were immediately able to take up propionate, likely at a similar rate as acetate. However, an enrichment of GAOs with acetate as the sole carbon source took up propionate at a much slower rate (only about 5% of the rate of acetate uptake on a COD basis) during a short‐term switch in carbon source. A GAO enrichment with propionate as the sole carbon source took up acetate at a rate that was less than half of the propionate uptake rate on a COD basis. These results, along with literature reports showing that PAOs fed with propionate (also dominated by Accumulibacter) can immediately switch to acetate, suggesting that PAOs are more adaptable to changes in carbon source as compared to GAOs. This study suggests that the PAO and GAO competition could be influenced in favour of PAOs through the provision of propionate in the feed or even by regularly switching the dominant VFA species in the wastewater. Further study is necessary in order to provide greater support for these hypotheses. © 2005 Wiley Periodicals, Inc.
A simple method to estimate the contribution of biological floc and reactor‐solution to mass transfer of oxygen in activated sludge processes
Authors: Mahendraker Venkatram , Mavinic Donald S. , Rabinowitz Barry
Published: May 2005

In this study, the mass transfer coefficient of biological floc (KLabf) was estimated from the mass transfer coefficient of the mixed‐liquor (KLaf) and the reactor‐solution (KLae). The biological floc resistance (BFR) and reactor‐solution resistance (SR) were defined as the reciprocal of KLabf and KLae, respectively, by applying the concept of serial‐resistance originally presented in two‐film theory (Lewis and Whitman (1924) Ind Eng Chem 16:1215–1220). The specific biological floc resistance (SBFR) was defined as biological floc resistance per unit biomass concentration. The data indicated that an activated sludge process yielding low BFR/MLR and BFR/SR tended to produce higher oxygen transfer efficiency. Surprisingly, the reactor‐solution posed the same level of resistance as clean water in all experiments, except in a 5‐day SRT, non‐nitrifying, completely mixed activated sludge (CMAS) process run. Furthermore, SBFR successfully represented biological floc and showed a positive correlation to sludge volume index (SVI). In addition, SBFR/SR and oxygen transfer efficiency (OTEf) followed an exponential relationship for the complete data set. The method of separating the mixed‐liquor into biological floc and reactor‐solution improved the understanding of oxygen transfer under process conditions, without resorting to intrusive techniques or direct handling of fragile biological floc. © 2005 Wiley Periodicals, Inc.
From ‘community’ to ‘neighbourhood’ policing: police community support officers and the ‘police extended family’ in London
Authors: Johnston Les
Published: May 2005

Community policing lacks a coherent definition. Despite this, the term has been used as a rhetorical device to support nostalgic and state‐centric models of policing. These models are increasingly challenged by diversity. Government has responded to this challenge by advocating an ‘extended family’ model of policing. This paper explores the role of Police Community Support Officers (PCSOs) in the ‘extended family’ model. It draws upon research carried out on PCSOs in London between October 2002 and December 2003. The paper consists of four sections. The first considers the extent of PCSO integration within the Metropolitan Police Service (MPS). The second looks at the impact of PCSO recruitment on the goal of diversifying the MPS workforce. Section three considers public attitudes towards PCSOs in London. The final section considers PCSOs in a national context, focusing on two issues: the relationship between PCSO policy implementation and the ‘evidence‐base’ used to justify it; and the future role of PCSOs in ‘neighbourhood policing’, the latest incarnation of community policing. Copyright © 2005 John Wiley & Sons, Ltd.
Kanamycin A‐Derived Cationic Lipids as Vectors for Gene Transfection
Authors: Sainlos Matthieu , Hauchecorne Michelle , Oudrhiri Noufissa , Zertal‐Zidani Samia , Aissaoui Abderrahim , Vigneron Jean‐Pierre , Lehn Jean‐Marie , Lehn Pierre
Published: May 2005

Cationic lipids nowadays constitute a promising alternative to recombinant viruses for gene transfer. We have recently explored the transfection potential of a new class of lipids based upon the use of aminoglycosides as cationic polar headgroups. The encouraging results obtained with a first cholesterol derivative of kanamycin A prompted us to investigate this family of vectors further, by modulating the constituent structural units of the cationic lipid. For this study, we have investigated the transfection properties of a series of new derivatives based on a kanamycin A scaffold. The results primarily confirm that aminoglycoside‐based lipids are efficient vectors for gene transfection both in vitro and in vivo (mouse airways). Furthermore, a combination of transfection and physicochemical data revealed that some modifications of the constitutive subunits of kanamycin A‐based vectors were associated with substantial changes in their transfection properties.
Molecular Basis of the Interaction Specificity between the Human Glucocorticoid Receptor and Its Endogenous Steroid Ligand Cortisol
Authors: von Langen Johannes , Fritzemeier Karl‐Heinrich , Diekmann Stephan , Hillisch Alexander
Published: May 2005

We analyzed the binding of five steroids to the human glucocorticoid receptor (hGR) experimentally as well as theoretically. In vitro, we measured the binding affinity of aldosterone, cortisol, estradiol, progesterone, and testosterone to hGR in competition with the ligand dexamethasone. The binding affinity relative to the endogenous ligand cortisol (100 %) is reduced for progesterone (22 %) and aldosterone (20 %) and is very weak for testosterone (1.5 %) and estradiol (0.2 %). In parallel, we constructed a homology model of the hGR ligand‐binding domain (LBD) based on the crystal structure of the human progesterone receptor (hPR). After docking the five steroids into the hGR model ligand‐binding pocket, we performed five separate 4‐ns molecular dynamics (MD) simulations with these complexes in order to study the complex structures. We calculated the binding affinities with two different approaches (MM/PBSA, FlexX) and compared them with the values of the experimentally determined relative binding affinities. Both theoretical methods allowed discrimination between strongly and weakly binding ligands and recognition of cortisol as the endogenous ligand of the hGR in silico. Cortisol binds most strongly due to a nearly perfect steric and electrostatic complementarity with the hGR binding pocket. Chemically similar ligands such as estradiol, testosterone, and progesterone also fit into the hGR binding pocket, but they are unable to form all those contacts with the amino acids of the protein that are necessary to yield a stable, transcriptionally active receptor conformation. Our analysis thus explains the selectivity of the human glucocorticoid receptor for its endogenous ligand cortisol at a molecular level.
Domain‐Selective Ligand‐Binding Modes and Atomic Level Pharmacophore Refinement in Angiotensin I Converting Enzyme (ACE) Inhibitors
Authors: Tzakos Andreas G. , Gerothanassis Ioannis P.
Published: May 2005

Somatic ACE (EC 3.4.15.1), a ZnII metalloproteinase, is composed of functionally active N and C domains resulting from tandem gene duplication. Despite the high degree of sequence similarity between the two domains, they differ in substrate and inhibitor specificity and in their activation by chloride ions. Because of the critical role of ACE in cardiovascular and renal diseases, both domains are attractive targets for drug design. Putative structural models have been generated for the interactions of ACE inhibitors (lisinopril, captoril, enalaprilat, keto‐ACE, ramiprilat, quinaprilat, peridoprilat, fosinoprilat, and RXP 407) with both the ACE_C and the ACE_N domains. Inhibitor‐domain selectivity was interpreted in terms of residue alterations observed in the four subsites of the binding grooves of the ACE_C/ACE_N domains (S1: V516/N494, V518/T496, S2: F391/Y369, E403/R381, S1′: D377/Q355, E162/D140, V379/S357, V380/T358, and S2′: D463/E431, T282/S260). The interactions governing the ligand–receptor recognition process in the ACE_C domain are: a salt bridge between D377, E162, and the NH2 group (P1′ position), a hydrogen bond of the inhibitor with Q281, the presence of bulky hydrophobic groups in the P1 and P2′ sites, and a stacking interaction of F391 with a benzyl group in the P2 position. In ACE_N these interactions are: hydrogen bonds of the inhibitor with E431, Y369, and R381, and a salt bridge between the carboxy group in the P2 position of the inhibitor and R500. The calculated complexes were evaluated for their consistency with structure–activity relationships and site‐directed mutagenesis data. A comparison between the calculated interaction free energies and the experimentally observed biological activities was also made. Pharmacophore refinement was achieved at an atomic level, and might provide an improved basis for structure‐based rational design of secondgeneration, domain‐selective inhibitors.
Creating Space for Large Secondary Alcohols by Rational Redesign of Candida antarctica Lipase B
Authors: Magnusson Anders O. , Rotticci‐Mulder Johanna C. , Santagostino Alberto , Hult Karl
Published: May 2005

The active site of Candida antarctica lipase B (CALB) hosts the catalytic triad (Ser‐His‐Asp), an oxyanion hole and a stereospecificity pocket. During catalysis, the fast‐reacting enantiomer of secondary alcohols places its medium‐sized substituent in the stereospecificity pocket and its large substituent towards the active‐site entrance. The largest group to fit comfortably in the stereospecificity pocket is ethyl, and this restricts the number of secondary alcohols that are good substrates for CALB. In order to overcome this limitation, the size of the stereospecificity pocket was redesigned by changing Trp104. The substrate specificity of the Trp104Ala mutant compared to that of the wild‐type lipase increased 270 times towards heptan‐4‐ol and 5500 times towards nonan‐5‐ol; this resulted in the high specificity constants 1100 and 830 s−1 M−1, respectively. The substrate selectivity changed over 400 000 times for nonan‐5‐ol over propan‐2‐ol with both Trp104Ala and the Trp104Gln mutations.
Chemoenzymatic Synthesis of HIV‐1 gp41 Glycopeptides: Effects of Glycosylation on the Anti‐HIV Activity and α‐Helix Bundle‐Forming Ability of Peptide C34
Authors: Wang Lai‐Xi , Song Haijing , Liu Shuwen , Lu Hong , Jiang Shibo , Ni Jiahong , Li Hengguang
Published: May 2005

C34 is a 34‐mer peptide derived from the C‐terminal ectodomain of HIV‐1 envelope glycoprotein, gp41. The C34 region in native gp41 carries a conserved N‐glycan at Asn637 and the sequence is directly involved in the virus–host membrane fusion, an essential step for HIV‐1 infection. This paper describes the synthesis of glycoforms of C34 which carry a monosaccharide, a disaccharide, and a native oligosaccharide moiety. The synthesis of the glycopeptide which carries a native high‐mannose type N‐glycan was achieved by a chemoenzymatic approach by using an endoglycosidase‐catalyzed oligosaccharide transfer as the key step. The effects of glycosylation on the inhibitory activity and the helix‐bundle forming ability of C34 were investigated. It was found that glycosylation moderately decreases the anti‐HIV activity of C34 and, in comparison with C34, glyco‐C34 forms less compact six‐helix bundles with the corresponding N‐terminal peptide, N36. This study suggests that conserved glycosylation modulates the anti‐HIV activity and conformations of the gp41 C‐peptide, C34.
Microheterogeneous Solvation for Aminolysis Reactions in AOT‐Based Water‐in‐Oil Microemulsions
Authors: García‐Río Luis , Mejuto Juan Carlos , Pérez‐Lorenzo Moisés
Published: May 2005

A kinetic study was carried out on the aminolysis of p‐nitrophenyl acetate (NPA) by n‐decylamine (DEC), piperazine (PIP) and sarcosine (SAR) in AOT/isooctane/water (w/o) microemulsions. By using the pseudophase model both the rate constants at the interface, ${k{{\,{\rm i}\hfill \atop 2\hfill}}}$, and the water microdroplet, ${k{{\,{\rm w}\hfill \atop 2\hfill}}}$, can be obtained. The obtained results show that ${k{{\,{\rm i}\hfill \atop 2\hfill}}}$ increases together with the water content of the microemulsion, whereas ${k{{\,{\rm w}\hfill \atop 2\hfill}}}$ increases as the water content of the system decreases. In the aqueous microdroplet the predominant interaction Na+⋅⋅⋅OH2 causes a decrease in the strength of the hydrogen bonds and therefore facilitates the desolvation of the reagents as W decreases. This desolvation of the reagents causes the increase of ${k{{\,{\rm w}\hfill \atop 2\hfill}}}$ as W decreases. In the interface of the microemulsion the predominant interaction SO3−⋅⋅⋅HOH causes an increase in the electronic density on the water molecules and the consequent decrease in their efficiency in the solvation of the partial negative charge, which develops on the carbonyl oxygen atom in the transition state of the reaction. This decrease in the solvation causes ${k{{\,{\rm i}\hfill \atop 2\hfill}}}$ to decrease together with the water content of the system.
Synthesis and Properties of Chiral Ammonium‐Based Ionic Liquids
Authors: Pernak Juliusz , Feder‐Kubis Joanna
Published: May 2005

New chiral ammonium‐based ionic liquids containing the (1R,2S,5R)‐(−)‐menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)‐(−)‐menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air‐ and moisture‐stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single‐crystal X‐ray structure of butyldimethyl[(1R,2S,5R)‐(−)‐menthoxymethyl]ammonium chloride has been determined. The chiral, room‐temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)‐(−)‐menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities.