bluuebunny/crossref_metadata_2025 huggingface dataset:
Getting more out of an incommensurately modulated structure: the example of K5Yb(MoO4)4
Authors: Arakcheeva Alla , Chapuis Gervais
Published: January 2006

A method based on the superspace approach is presented with the aim of generating a family of modular structures from a single incommensurately modulated structure. This approach based on the variation of the modulation vector q is applied to the generation of the K5Yb(MoO4)4, potassium ytterbium tetramolybdate, family of modular structures. The β coefficient of the modulation vector q = βb* is a temperature-dependent variable which determines the modification. Our method gives a unified frame to describe and explain the three temperature-dependent phases of K5Yb(MoO4)4. Phase β can be represented as a polytypic modification with 1/2b* ≤ q ≤ 2/3b*; phases γ (q = 1/2b*) and α (q = 1b*) are the lowest and the highest temperature members of the K5Yb(MoO4)4 family, respectively.
Cluster approach to the Ti2Ni structure type
Authors: Ivanović N. , Rodić D. , Koteski V. , Radisavljević I. , Novaković N. , Marjanović D. , Manasijević M. , Koički S.
Published: January 2006

It has been established that the 16(c) first coordination clusters in the Ti2Ni structure type (space group Fd3m) follow icosahedral-face orientational ordering along regular tetrahedron edge directions. The actual crystal structure appears due to the prevalence of the face-centred cubic translational ordering over the cluster assembling. This way, the competition of the `regular' crystal phase and its icosahedral analogue is reconstructed at the atomic level. The model accounts for the markedly different electronic characteristics at the different crystallographic positions obtained by hyperfine interaction measurements, and other curious experimental facts help to create an exact physical definition of the first coordination in the solid state and to distinguish between various structure types on fundamental principles.
Review of polyhedral distortions as a multi-scale minimization of the electric polarization and their correlations with physical properties
Authors: Benabbas Abderrahim
Published: January 2006

The Jahn–Teller (JT) and non-Jahn–Teller polyhedral distortions are reviewed within the same context, based on a multi-scale minimization of the electric polarization by handling formal ionic valences and valence electron density. This model is applied to tetragonal distortions of octahedra, particularly in K2NiF4 structures with different formula types, along with doping. The predictions are always in good agreement with the observed data. In particular, the ferrodistortive order of JT distortions is obtained from formal charge polarizations, while the antiferrodistortive one is adopted when only the valence electron density is involved. The correlations between physical properties and octahedral elongations through the crystal structures on one side and chemical compositions on the other side are discussed according to this model for high-Tc
cuprate superconductors and CMR manganites.
Hydrated metal(II) complexes of N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl) derivatives of glycine, glycylglycine, threonine, serine, valine and methionine: a monomeric complex and coordination polymers in one, two and three dimensions linked by hydrogen bonding. Corrigendum
Authors: Godino Salido M. Luz , Arranz Mascarós Paloma , López Garzón Rafaél , Gutiérrez Valero M. Dolores , Low John N. , Gallagher John F. , Glidewell Christopher
Published: January 2006

Some of the data collection details for compound (VIII) were incorrectly given in Table 1 of Godino Salido et al. (2004). The data for compound VIII in this paper were collected using synchrotron radiation at the Daresbury SRS station 9.8, λ = 0.6935 Å (Cernik et al., 1997; Clegg, 2000). The data were collected using a Bruker SMART 1K CCD diffractometer using ω rotation with narrow frames. The computer program used in the data collection was SMART (Bruker, 2001) and for cell refinement and data reduction SAINT (Bruker, 2001).
The redox couple of the cytochrome c cyanide complex: The contribution of heme iron ligation to the structural stability, chemical reactivity, and physiological behavior of horse cytochrome c
Authors: Schejter Abel , Ryan Michael D. , Blizzard Erica R. , Zhang Chongyao , Margoliash Emanuel , Feinberg Benjamin A.
Published: January 2006

Contrary to most heme proteins, ferrous cytochrome c does not bind ligands such as cyanide and CO. In order to quantify this observation, the redox potential of the ferric/ferrous cytochrome c–cyanide redox couple was determined for the first time by cyclic voltammetry. Its E0′ was −240 mV versus SHE, equivalent to −23.2 kJ/mol. The entropy of reaction for the reduction of the cyanide complex was also determined. From a thermodynamic cycle that included this new value for the cyt c cyanide complex E0′, the binding constant of cyanide to the reduced protein was estimated to be 4.7 × 10−3 LM−1 or 13.4 kJ/mol (3.2 kcal/mol), which is 48.1 kJ/mol (11.5 kcal/mol) less favorable than the binding of cyanide to ferricytochrome c. For coordination of cyanide to ferrocytochrome c, the entropy change was earlier experimentally evaluated as 92.4 Jmol−1K−1 (22.1 e.u.) at 25 K, and the enthalpy change for the same net reaction was calculated to be 41.0 kJ/mol (9.8 kcal/mol). By taking these results into account, it was discovered that the major obstacle to cyanide coordination to ferrocytochrome c is enthalpic, due to the greater compactness of the reduced molecule or, alternatively, to a lower rate of conformational fluctuation caused by solvation, electrostatic, and structural factors. The biophysical consequences of the large difference in the stabilities of the closed crevice structures are discussed.
Activation of MEK/ERK and PI3K/Akt pathways by fibronectin requires integrin αv‐mediated ADAM activity in hepatocellular carcinoma: A novel functional target for gefitinib
Authors: Matsuo Mitsuhiro , Sakurai Hiroaki , Ueno Yoko , Ohtani Osamu , Saiki Ikuo
Published: January 2006

We have shown that the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib (‘Iressa’, ZD1839) inhibits the development of intrahepatic metastases of hepatocellular carcinoma CBO140C12, and EGFR transactivation by tumor necrosis factor‐α is a possible target of gefitinib. In the present study, we focused on the fibronectin (FN)‐dependent signaling pathway to further elucidate the antimetastatic activity of gefitinib in CBO140C12 cells. We initially observed that FN induced activation of extracellular signal‐regulated kinase (ERK), p38 and Akt, as well as cell proliferation and CBO140C12 cell invasion. These responses were mediated by EGFR tyrosine kinase, because gefitinib inhibited these effects of FN. FN‐induced ERK, p38 and Akt activation was partly blocked by the Arg‐Gly‐Asp (RGD)‐pseudo‐peptide FC‐336, anti‐αv integrin antibody RMV‐7, the broad‐spectrum matrix metalloprotease inhibitor GM6001 and the broad spectrum a disintegrin and metalloprotease (ADAM) inhibitor TAPI‐1. But these inhibitors had no effect on EGF‐induced signaling pathways, suggesting that integrins and ADAM may be upstream components of EGFR in these responses. These results suggest that FN‐induced activation of ERK, p38, Akt, cell proliferation and invasion was mediated, at least in part, via integrins, ADAM and EGFR, and that this FN‐induced signaling pathway might be involved in the antimetastatic activity of gefitinib. (Cancer Sci2006; 97: 155 –162)
Use of hydroxy‐methyl‐glutaryl coenzyme A reductase inhibitors is associated with risk of lymphoid malignancies
Authors: Iwata Hiroshi , Matsuo Keitaro , Hara Shigeo , Takeuchi Kengo , Aoyama Tomonori , Murashige Naoko , Kanda Yoshinobu , Mori Shin‐ichiro , Suzuki Risturo , Tachibana Shintaro , Yamane Masaaki , Odawara Masato , Mutou Yoshitomo , Kami Masahiro
Published: January 2006

It has been speculated that the use of hydroxy‐methyl‐glutaryl coenzyme A reductase inhibitors (statins) is associated with the risk of malignant diseases. Considering their immunosuppressive activities, malignant diseases that are associated with an immunosuppressive status seem feasible to examine the association. We therefore examined the association between statin use and development of lymphoid malignancies in a case‐control study. Cases were 221 consecutive incident cases with histopathologically proven lymphoid malignancies (lymphoma and myeloma), hospitalized in the Department of Hematology of Toranomon Hospital (Tokyo, Japan) between 1995 and 2001. Two independent control groups, comprising 442 and 437 inpatients without malignancies from the Departments of Orthopedics and Otorhinolaryngology of the same hospital, were selected to test for consistency of association. Controls were matched individually with cases for age, sex and year of admission. Subject information, including statin use, was abstracted from medical records at the time of hospitalization. Strength of association was evaluated as an adjusted odds ratios (aOR) using a conditional logistic regression model. A higher frequency of statin use was found among patients with lymphoid malignancies in comparison with both orthopedic (aOR 2.11, 95% CI 1.20–3.69, P = 0.009) and otorhinolaryngology patients (aOR 2.59, 95% CI 1.45–4.65, P = 0.001), the significance being maintained when the two control groups were combined (aOR 2.24, 95% CI 1.37–3.66, P = 0.001). In conclusion, we observed an elevated risk of lymphoid malignancy with statin use among Japanese patients. Further evaluations in different populations are required to draw conclusions as to the carcinogenicity of lymphoid malignancies with statin use. (Cancer Sci 2006; 97: 133 –138)
Attention deficit hyperactivity disorder: a review of the essential facts
Authors: Daley D.
Published: January 2006

Attention deficit hyperactivity disorder (ADHD) is a complex disorder, where both genetic and environmental influences make a substantial contribution to the risk for the disorder. One of the challenges facing clinicians is to simplify for parents the multifaceted reasons why their child may have developed ADHD, explain the associated symptoms, and encourage parents to participate in intervention. Increasing parents understanding about ADHD should make them better informed about the disorder, more likely to consent to intervention, and increase adherence to both psychosocial and pharmacological treatment. The aim of this review is to provide clinicians with a brief synopsis of our current understanding about the aetiology of ADHD, co‐morbidity and associated problems, developmental course and intervention options.
Prescribing practices of psychiatrists and primary care physicians caring for children with mental illness
Authors: Harpaz‐Rotem I. , Rosenheck R. A.
Published: January 2006

Objective  Although several studies have found that the most effective treatment for both youths and adults diagnosed with mood disorders is the combination of psychotherapy and medications, psychiatrists have been increasingly providing psychotropic medications without psychotherapy to these populations. At the same time, primary care physicians (PCPs) have become increasingly involved in prescribing psychotropic medications. This study compared the prescribing patterns of PCPs and psychiatrists caring for children with mental illness.

Methods  Data were extracted from the MarketScan® database, which compiles claims from private health insurance plans nationwide. Of 40 639 children who received mental health services during calendar year 2000 (6.33% of all covered children), we identified 5485 who initiated a new episode of treatment. Multiple regression was use to adjust for differences in patient characteristics.

Results  While PCPs were more likely to see young children and psychiatrists saw children with more numerous mental illnesses, there were no significant differences between PCPs and psychiatrists in either the proportion of patients who received psychotropic medication, the frequency of clinical contacts, or the dosages or types of medications prescribed. Patients seen in more actively managed Point of Service plans were more likely to receive medication than those seen in preferred provider or indemnity plans.

Conclusions  This study found no significant differences between psychiatrists and PCPs in psychotropic prescribing practices. In view of the limited availability of child psychiatrists and the decreased availability of psychotherapy in combination with medications, collaborative care models in which non‐physician mental health specialists and PCPs work together may increase the availability of effective mental health services for youths.
Aggregation among resource patches can promote coexistence in stream‐living shredders
Authors: PRESA ABÓS C. , LEPORI F. , MCKIE B. G. , MALMQVIST B.
Published: January 2006

1. We conducted a new single‐site study and a meta‐analysis of pre‐existing studies from multiple streams to assess whether intraspecific aggregation among leaf packs promotes coexistence among leaf‐eating invertebrates (shredders) in Swedish streams.

2. In the single‐site study, 48 standardised leaf bags were exposed for 1 month for shredder colonisation in a homogeneous glide of a forested stream. Current velocity, water depth and substratum composition were additionally assessed to investigate how these factors affected shredder distributions.

3. The meta‐analysis included information on shredder colonisation of leaf packs from seven other studies of detritus decomposition to assess patterns of aggregation. Intra‐ and interspecific aggregation and their relative strength were assessed using indices (J,CandArespectively) originally developed for terrestrial insects also dependent on patchy and ephemeral resources.

4. In both parts of the study, intraspecific aggregation was much stronger than interspecific aggregation, which was weak overall, indicating that the conditions under which aggregation is expected to facilitate coexistence were fulfilled in our shredder assemblages.

5. In the single‐site study, shredder abundances were weakly associated with environmental variables suggesting that habitat heterogeneity only partly explains aggregation patterns.

6. Our results strongly suggest that shredder diversity in streams, particularly during periods of leaf limitation (such as might occur in spring), is promoted by the aggregation of individual species among patches of resource.
Habitat partitioning of native and exotic Daphnia in gradients of temperature and food: mesocosm experiments
Authors: HAVEL JOHN E. , LAMPERT WINFRIED
Published: January 2006

1. Invasion of tropical zooplankton into temperate lakes provides an interesting opportunity to explore habitat segregation in a thermal gradient.

2. We explored differing vertical positioning of native and exotic Daphnia (Daphnia mendotae and Daphnia lumholtzi) in a large indoor mesocosm system (Plön plankton towers) during 2 month‐long experiments. The two towers were manipulated to provide gradients of both temperature (15–29 °C) and algal food (0.05–0.58 mg C L−1) and a day–night cycle.

3. Both juvenile and adult D. lumholtzi showed a ‘typical’ vertical migration pattern, with higher densities in the epilimnion at night than during the day. They avoided the food‐poor middle layer. In contrast, D. mendotae adults showed little tendency to migrate into the epilimnion at night, remaining in the cooler hypolimnion while juveniles migrated. The vertical distribution of D. mendotae appeared unaffected by the presence of D. lumholtzi.

4. The strong migration behaviour of D. lumholtzi in the absence of fish cues suggests that this behaviour may be a constitutive trait. Habitat partitioning of the two species is probably the result of different thermal tolerances, with D. mendotae constrained to remaining in deeper water by high temperatures in the epilimnion and the tropical D. lumholtzi able to use the warm epilimnion at night.
Dynamic patch mosaics and channel movement in an unconfined river valley of the Olympic Mountains
Authors: LATTERELL JOSHUA J. , SCOTT BECHTOLD J. , O'KEEFE THOMAS C. , VAN PELT ROBERT , NAIMAN ROBERT J.
Published: January 2006

1. River valleys resemble dynamic mosaics, composed of patches which are natural, transient features of the land surface produced by the joint action of a river and successional processes over years to centuries. They simultaneously regulate and reflect the distribution of stream energy and exchanges of sediment, wood and particulate organic matter between riparian and aquatic environments.

2. We determined the structure, composition, dynamics and origin of seven patch types at the reach scale in the Queets River valley in the temperate coastal forests of the Olympic Mountains, Washington (U.S.A.). Patch types included: (1) primary and (2) secondary channels; (3) pioneer bars; (4) developing and (5) established floodplains; and (6) transitional and (7) mature fluvial terraces.

3. Lateral channel movements strongly shape patch distribution, structure and dynamics. The primary channel moved laterally 13 m year−1, on average from 1939 to 2002, but was highly variable among locations and over time. Mean lateral movement rates ranged from 1 to 59 m year−1and moving averages (2 km) ranged from 3 to 28 m year−1throughout the valley.

4. Each patch type exhibited characteristic vegetation, soil and accumulations of large wood. Pioneer bars contained peak stem density (69 778 stems ha−1) and volume of large wood (289 m3 ha−1). Mature fluvial terraces contained the highest mean stem (1739 m3 ha−1) and canopy volume (158 587 m3 ha−1). These patches also contained the most soil nitrogen (537 kg ha−1) and carbon (5972 kg ha−1).

5. Patch half‐life (the time required for half of the existing patches to be eroded) ranged from 21 to 401 years among forested patch types. Erosion rates were highest in pioneer bars (2.3% year−1) and developing floodplains (3.3% year−1), compared with only 0.17% year−1in mature fluvial terraces. New forests formed continually, as pioneering vegetation colonised 50% of the channel system within 18 years, often unsuccessfully.

6. In the Queets River, the structure, composition, and dynamics of the patchy riparian forest depends on the interplay between channel movements and biophysical feedbacks between large wood, living vegetation and geomorphic processes. The cycle of patch development perpetuates a shifting‐mosaic of habitats within the river valley capable of supporting diverse biotic assemblages.
Origin and dispersal of bluegill sunfish, Lepomis macrochirus, in Japan and Korea
Authors: KAWAMURA KOUICHI , YONEKURA RYUJI , KATANO OSAMU , TANIGUCHI YOSHINORI , SAITOH KENJI
Published: January 2006

The bluegill sunfish, Lepomis macrochirus, is a notorious exotic species in many freshwater ecosystems, currently expanding its distribution worldwide. In 1960, a small group of bluegills captured in the Mississippi River at Guttenberg in Iowa were imported to Japan as a gift from the mayor of Chicago to the Japanese government. The offspring of these fish were released into the wild in Japan and also in Korea. Over 40 years after this first introduction, L. macrochirus now occupies all the freshwater ecosystems of both countries. We compared invading populations of L. macrochirus in Japan and Korea with native populations in the USA, using PCR–RFLP (polymerase chain reaction–restricted fragment length polymorphism) analyses of mitochondrial DNA, to estimate the origin and dispersal of L. macrochirus in Japan and Korea. Five haplotypes of mitochondrial DNA detected in Japanese and Korean populations completely coincided with the haplotypes of the Guttenberg population. Haplotype diversity of invading populations was shown to be highest in populations established in the 1960s, while genetic variability was lower in more recently established populations. Our results suggest that all L. macrochirus in Japan and Korea have originated from the 15 fish first introduced in 1960. Low haplotype diversity in newly established populations is probably due to genetic drift arising from repeated population bottlenecks, while the high similarity of haplotypes among neighbouring populations is considered to reflect the history of transplantation by humans.
Assessment of arbuscular mycorrhizal fungal diversity in roots of Solidago gigantea growing in a polluted soil in Northern Italy
Authors: Vallino Marta , Massa Nadia , Lumini Erica , Bianciotto Valeria , Berta Graziella , Bonfante Paola
Published: January 2006

The arbuscular mycorrhizal (AM) status of Solidago gigantea was investigated in a contaminated site of Northern Italy, where the chemical industry ACNA (Associated National Chemical Companies) was active till 1999. To counteract the devastating effects of chemicals and to allow re‐vegetation, soil from an uncontaminated area was used to cover the highly polluted hills of the industrial site about 25 years ago. On the basis of the current floristic features, the hill was divided into four areas. Heavy metal content in soil and in plant shoots and roots was determined by chemical analysis. The AM fungal community colonizing S. gigantea was investigated from a morphological and a molecular point of view. All plants were modestly colonized, but the fungal structures within the roots were normal. By PCR‐RFLP and sequencing of 18S rDNA, 14 AM fungal types were identified: three of them were present in all the considered areas and nine appeared to be specific to certain areas. Glomus was the predominant AM genus. Our analysis demonstrates the presence and the relatively high level of AM species variety and shows how a remediation programme based on cover‐soil has been efficient to restore a community of AM fungi, tolerant enough to proliferate in a still contaminated soil.
Nucleic acid binding agents exert local toxic effects on neurites via a non‐nuclear mechanism
Authors: Pin Sokhon , Chen Huiling , Lein Pamela J. , Wang Michael M.
Published: January 2006

The mechanism by which drugs that target nucleic acids cause neurotoxicity is not well described. We characterized the neurotoxicity of Hoechst 33342 (bis‐benzimide), a common cell permeable nuclear dye, in primary neuronal cultures. The mechanism of cell death was not apoptotic, as death is rapid, not accompanied by typical nuclear morphological changes, and is insensitive to inhibitors of transcription, translation and caspase activity. In addition, free‐radical scavenging agents failed to attenuate cell death, and damage was not accompanied by mitochondrial dysfunction. Neuronal processes of cells exposed to Hoechst 33342 display dramatic fragmentation prior to cell death. When this compound was applied selectively to the distal axons of sympathetic neurons grown in compartmented cultures, the distal axons were destroyed. However, the proximal processes present in the cell body compartment were spared, demonstrating direct axonal toxicity rather than a remote effect of nuclear dysfunction. Other cell‐permeable nucleic acid binding dyes similarly caused rapid dendritic and axonal toxicity. The hypothesis that these nucleic acid binding dyes target RNA localized to dendrites and axons is supported by observations that RNaseV1 induced similar, rapid neurite fragmentation. We conclude that the neurotoxic effects of nucleic acid binding compounds are mediated, at least in part, by direct neurite injury, which does not require involvement of the cell body and nucleus.
Community‐Level Uninsurance and the Unmet Medical Needs of Insured and Uninsured Adults
Authors: Pagán José A. , Pauly Mark V.
Published: January 2006

Objective.To examine the relationship between community‐level uninsurance rates and the self‐reported unmet medical needs of insured and uninsured adults in the U.S.

Data Sources.2000–2001 Community Tracking Study, which includes data from 60 randomly selected U.S. communities. The sample is representative of the contiguous U.S. states.

Study Design.Multilevel logistic regressions were employed to investigate whether the local uninsurance rate was related to having reported unmet medical needs within the last year. The models also included individual and community variables that could be potentially related to both community uninsurance rates and having reported unmet medical needs.

Principal Findings.The community uninsurance rate was positively associated with having reported unmet medical needs, but only for insured adults. On average, a five percentage point increment in the local uninsured population is associated with a 10.5 percent increase in the likelihood that an insured adult will report having unmet medical needs during the 12‐month period studied.

Conclusion.Local health care delivery systems seem to be negatively affected by high uninsurance rates. These effects could have negative consequences for health care access, even for individuals who are themselves insured.
Müllerian dysgenesis: A review of recent outcomes at Royal Hospital for Women
Authors: MIZIA Karen , BENNETT Michael J. , DUDLEY Jan , MORRISEY Jennifer
Published: January 2006

Background:  Müllerian dysgenesis occurs in approximately 1 in 5000 live‐born females. There have been many methods described for creation of a functionally useful vagina in cases of Müllerian dysgenesis. Given the number of available methods and the infrequency of the condition, outcome data can be difficult to obtain.

Aim:  To perform a retrospective review of presentation, treatment and outcomes in cases of Müllerian dysgenesis seen at the adolescent gynaecology unit at the Royal Hospital for Women, Sydney.

Methods:  Thirty women with Müllerian dysgenesis were identified between January 2000 and December 2004. Of these, 23 had Müllerian agenesis and seven had partial vaginal agenesis. As this audit and review conform with the standards established by the National Health and Medical Research Council for ethical quality review, ethics approval was not sought.

Results:  Dilator therapy under the guidance of a trained clinical nurse educator was successful in creating a functionally useful vagina and was well tolerated in all cases of Müllerian agenesis. Patients suffering from segmental vaginal agenesis all had surgical creation of a neovagina with the aid of an amnion vaginoplasty. All patients who were referred following surgical drainage of their haematocolpos outside the unit became infected and needed to undergo further surgery prior to creation of a neovagina. Fibrotic vaginal bands developed only in these patients.

Conclusion:  The outcomes reinforce the TASPAG guidelines of management for Müllerian dysgenesis, which suggest that dilators are generally effective in creating a functionally useful vagina, and if surgery is required, the primary operation should be definitive and performed by well‐trained experts.
Socioeconomic Status and Patterns of Parent–Adolescent Interactions
Authors: Chen Edith , Berdan Louise E.
Published: January 2006

This study investigated reciprocity in parent–adolescent interactions among 102 families from lower or higher socioeconomic status (SES) backgrounds. Negative behaviors between parents and adolescents were more reciprocal (strongly correlated) in higher SES than lower SES families, and this reciprocity correlated with higher family relationship quality. Lower SES families exhibited reciprocity related to withdrawn behaviors. Reciprocity of these behaviors also correlated with higher relationship quality. Results suggest that SES differences provide insights into a more complex understanding of family relationships within contexts, and importantly, suggest that different types of reciprocity may each have its own adaptive value in families from different SES backgrounds.
Patterns of Competence and Adjustment Among Adolescents from Authoritative, Authoritarian, Indulgent, and Neglectful Homes: A Replication in a Sample of Serious Juvenile Offenders
Authors: Steinberg Laurence , Blatt‐Eisengart Ilana , Cauffman Elizabeth
Published: January 2006

The correlates of authoritative, authoritarian, indulgent, and neglectful parenting were examined within a sample of 1,355 14‐ to 18‐year‐olds adjudicated of serious criminal offenses. The sample is composed primarily of poor, ethnic‐minority youth living in impoverished urban neighborhoods. As has been found in community samples, juvenile offenders who describe their parents as authoritative are more psychosocially mature, more academically competent, less prone to internalized distress, and less prone to externalizing problems than their peers, whereas those who describe their parents as neglectful are less mature, less competent, and more troubled. Juvenile offenders who characterize their parents as either authoritarian or indulgent typically score somewhere between the two extremes, although those from authoritarian homes are consistently better functioning than those from indulgent homes. These patterns did not vary as a function of adolescents' ethnicity or gender.
Definitive Diagnosis of Descending Thoracic Aortic Dissection by Real Time/Live Three‐Dimensional Transthoracic Echocardiography
Authors: Yelamanchili Pridhvi , Nanda Navin C. , Patel Vinod , Bogabathina Hari , Baysan Oben
Published: January 2006

We describe a patient with descending thoracic aortic dissection in whom three‐ dimensional transthoracic echocardiography was able to clearly visualize the dissection flap en face as a sheet of tissue, as well as demonstrate a large communication between the true and false lumen in three dimensions, enabling a definitive diagnosis of dissection.
Overview of clinical studies in hemodiafiltration: What do we need now ?
Authors: CANAUD Bernard , MORENA Marion , LERAY‐MORAGUES Hélène , CHALABI Lofti , CRISTOL Jean‐Paul
Published: January 2006

Despite several technical advances in dialysis treatment modalities and a better patient care management including correction of anemia, suppression of secondary hyperparathyroidism, lipid and oxidative stress profiles improvement, the morbidity and the mortality of dialysis patients still remain still elevated. Recent prospective interventional trials in hemodialysis (HEMO study and 4D study) were not very conclusive in showing any significant improvement in dialysis patient outcomes. High‐efficiency convective therapies, such as online hemodiafiltration (HDF), are claimed to be superior to conventional diffusive hemodialysis (HD) in improving the dialysis efficacy and in reducing intradialytic morbidity and all‐cause and cardiovascular mortality in dialysis patients. The aim of this report was, first, to review the evidence‐based facts tending to prove the superiority of HDF vs. HD in terms of efficacy and tolerance, and, second, to analyze the needs to prove the clinical superiority of HDF in terms of reducing morbidity and all‐cause mortality of dialysis patients. A systematic review of studies comparing HDF and HD has been performed in the microbiological safety of online production, the solute removal capacity of small and medium‐size uremic toxins, and its implication in the reduction of the bioactive dialysis system vs. patient interaction. Major planned randomized international studies comparing HDF and HD in terms of morbidity and mortality have been reviewed. To conclude, it is thought that these long‐term prospective randomized trials will clarify on a scientific evidence‐based level the putative beneficial role of high‐efficiency HDF modalities on dialysis patient outcomes.
Water treatment and monitor disinfection
Authors: CAPPELLI Gianni , RICCARDI Marco , PERRONE Salvatore , BONDI Moreno , LIGABUE Giulia , ALBERTAZZI Alberto
Published: January 2006

Water treatment system and dialysis monitors are susceptible to microbial contaminations and periodical disinfection procedures are mandatory to obtain results requested from international standards and guidelines. Several chemical germicides or some physical treatments are on the market validated by device manufacturer according to medical device directives. With time, interfering substances from dialysis device or water are able to modify disinfection efficiency. Simulating‐use testing is not a common procedure to validate disinfectants and recent data document as biofilm represents the most important cause of disinfection inefficacy. Some international standards include tests in the presence of various interfering substances but their use is not widespread. When using a disinfectant, residue toxicity, material compatibility and potential risks for the staff also have to be considered. A quality assurance program has to be implemented to obtain adequate performances and to improve results on patients.
Cardiovascular dialysis instability and convective therapies
Authors: SANTORO Antonio
Published: January 2006

Acute hypotension is a frequent hemodialysis complication. Intratreatment vascular instability is a multifactorial process in which procedure‐related and patient‐related factors may influence the decrease in plasma volume and induce an impairment of cardiovascular regulatory mechanisms. Identification of the most susceptible patients and of the various risk factors may contribute to significantly improve cardiovascular stability during dialysis. In some high‐risk patients, monitoring and biofeedback of the various hemodynamic variables, together with an extensive use of convection, can prevent the appearance of symptomatic hypotension and help in averting its onset.
Clinical effects of online dialysate and infusion fluids
Authors: TETTA Ciro , DAVID Salvatore , MARCELLI Daniele , COGLIATI Paolo , FORMICA Marco , INGUAGGIATO Paola , PANICHI Vincenzo
Published: January 2006

Online hemodiafiltration appears to be the most effective technique of renal replacement therapy in many respects. Removal of small and high‐molecular weight substances is enhanced. Modern technology ensures a safe, online production of reinfusion fluids. Nonetheless, stringent maintenance rules are required for the production of sterile and nonpyrogenic‐dialysate solutions. In this review, we will critically review the state of the art of the clinical effects derived from the use of ultrapure dialysate and the online production of dialysate fluids in high‐flux hemodiafiltration.
Convection with conviction–online hemodiafiltration for all: Single center clinical observations
Authors: VELASCO Nestor
Published: January 2006

Online hemodiafiltration (HDF) has recently become an alternative to conventional hemodialysis for treatment of end‐stage renal disease with superior results. Clinical experience with HDF in unselected populations has not been widely published and a longitudinal study on such a group of patients is presented here.
Methylene analogues of adenosine 5′‐tetraphosphate
Authors: Guranowski Andrzej , Starzyńska Elżbieta , Pietrowska‐Borek Małgorzata , Jemielity Jacek , Kowalska Joanna , Darzynkiewicz Edward , Thompson Mark J. , Blackburn G. Michael
Published: January 2006

Adenosine 5′‐polyphosphates have been identified in vitro, as products of certain enzymatic reactions, and in vivo. Although the biological role of these compounds is not known, there exist highly specific hydrolases that degrade nucleoside 5′‐polyphosphates into the corresponding nucleoside 5′‐triphosphates. One approach to understanding the mechanism and function of these enzymes is through the use of specifically designed phosphonate analogues. We synthesized novel nucleotides: α,β‐methylene‐adenosine 5′‐tetraphosphate (pppCH2pA), β,γ‐methylene‐adenosine 5′‐tetraphosphate (ppCH2ppA), γ,δ‐methylene‐adenosine 5′‐tetraphosphate (pCH2pppA), αβ,γδ‐bismethylene‐adenosine 5′‐tetraphosphate (pCH2ppCH2pA), αβ, βγ‐bismethylene‐adenosine 5′‐tetraphosphate (ppCH2pCH2pA) and βγ, γδ‐bis(dichloro)methylene‐adenosine 5′‐tetraphosphate (pCCl2pCCl2ppA), and tested them as potential substrates and/or inhibitors of three specific nucleoside tetraphosphatases. In addition, we employed these p4A analogues with two asymmetrically and one symmetrically acting dinucleoside tetraphosphatases. Of the six analogues, only pppCH2pA is a substrate of the two nucleoside tetraphosphatases (EC 3.6.1.14), from yellow lupin seeds and human placenta, and also of the yeast exopolyphosphatase (EC 3.6.1.11). Surprisingly, none of the six analogues inhibited these p4A‐hydrolysing enzymes. By contrast, the analogues strongly inhibit the (asymmetrical) dinucleoside tetraphosphatases (EC 3.6.1.17) from human and the narrow‐leafed lupin. ppCH2ppA and pCH2pppA, inhibited the human enzyme with Ki values of 1.6 and 2.3 nm, respectively, and the lupin enzyme with Ki values of 30 and 34 nm, respectively. They are thereby identified as being the strongest inhibitors ever reported for the (asymmetrical) dinucleoside tetraphosphatases. The three analogues having two halo/methylene bridges are much less potent inhibitors for these enzymes. These novel nucleotides should prove valuable tools for further studies on the cellular functions of mono‐ and dinucleoside polyphosphates and on the enzymes involved in their metabolism.
Yeast oxidative stress response
Authors: Demasi Ana P. D. , Pereira Gonçalo A. G. , Netto Luis E. S.
Published: January 2006

We investigated the changes in the oxidative stress response of yeast cells suffering mitochondrial dysfunction that could impair their viability. First, we demonstrated that cells with this dysfunction rely exclusively on cytosolic thioredoxin peroxidase I (cTPxI) and its reductant sulfiredoxin, among other antioxidant enzymes tested, to protect them against H2O2‐induced death. This cTPxI‐dependent protection could be related to its dual functions, as peroxidase and as molecular chaperone, suggested by mixtures of low and high molecular weight oligomeric structures of cTPxI observed in cells challenged with H2O2. We found that cTPxI deficiency leads to increased basal sulfhydryl levels and transcriptional activation of most of the H2O2‐responsive genes, interpreted as an attempt by the cells to improve their antioxidant defense. On the other hand, mitochondrial dysfunction, specifically the electron transport blockage, provoked a huge depletion of sulfhydryl groups after H2O2 treatment and reduced the H2O2‐mediated activation of some genes otherwise observed, impairing cell defense and viability. The transcription factors Yap1 and Skn7 are crucial for the antioxidant response of cells under inhibited electron flow condition and probably act in the same pathway of cTPxI to protect cells affected by this disorder. Yap1 cellular distribution was not affected by cTpxI deficiency and by mitochondrial dysfunction, in spite of the observed expression alterations of several Yap1‐target genes, indicating alternative mechanisms of Yap1 activation/deactivation. Therefore, we propose that cTPxI is specifically important in the protection of yeast with mitochondrial dysfunction due to its functional versatility as an antioxidant, chaperone and modulator of gene expression.
Aspergillus fumigatus
C-5 Sterol Desaturases Erg3A and Erg3B: Role in Sterol Biosynthesis and Antifungal Drug Susceptibility
Authors: Alcazar-Fuoli Laura , Mellado Emilia , Garcia-Effron Guillermo , Buitrago Maria J. , Lopez Jordi F. , Grimalt Joan O. , Cuenca-Estrella J. Manuel , Rodriguez-Tudela Juan L.
Published: January 2006

Two
erg3
genes encoding C-5 sterol desaturase enzymes (Erg3A and Erg3B) in
Aspergillus fumigatus
were characterized with respect to their nucleotide sequences and null mutant phenotypes. Targeted disruption of the
erg3A
and
erg3B
genes and a double gene knockout,
erg3A
−
erg3B
−
, showed that they are not essential for
A. fumigatus
viability. Mutant phenotypes clearly showed that Erg3B is a C-5 sterol desaturase, but no apparent role for Erg3A in
A. fumigatus
ergosterol biosynthesis was found. Susceptibility to amphotericin B, itraconazole, fluconazole, voriconazole, and ketoconazole was not altered in isolates in which
erg3A
and
erg3B
were knocked out alone and in combination.
Bloodstream Infections Caused by Extended-Spectrum-β-Lactamase-Producing
Klebsiella pneumoniae
: Risk Factors, Molecular Epidemiology, and Clinical Outcome
Authors: Tumbarello Mario , Spanu Teresa , Sanguinetti Maurizio , Citton Rita , Montuori Eva , Leone Fiammetta , Fadda Giovanni , Cauda Roberto
Published: January 2006

Bloodstream infections caused by extended-spectrum-β-lactamase (ESBL)-producing
Klebsiella pneumoniae
isolates are a major concern for clinicians, since they markedly increase the rates of treatment failure and death. One hundred forty-seven patients with
K. pneumoniae
bloodstream infections were identified over a 5-year period (January 1999 to December 2003). The production of ESBLs in bloodstream isolates was evaluated by molecular methods. A retrospective case-case-control study was conducted to identify risk factors for the isolation of ESBL
-
producing
K. pneumoniae
or non-ESBL
-
producing
K. pneumoniae
isolates in blood cultures. Forty-eight cases infected with ESBL
-
producing
K. pneumoniae
isolates and 99 cases infected with non-ESBL
-
producing
K. pneumoniae
isolates were compared to controls. Risk factors for isolation of ESBL
-
producing
K. pneumoniae
isolates were exposure to antibiotic therapy (odds ratio [OR], 11.81; 95% confidence interval [CI], 2.72 to 51.08), age (OR, 1.14; 95% CI, 1.08 to 1.21), and length of hospitalization (OR, 1.10; 95% CI, 1.04 to 1.16). Independent determinants for isolation of non-ESBL
-
producing
K. pneumoniae
were previous urinary tract infection (OR, 8.50; 95% CI, 3.69 to 19.54) and length of hospitalization (OR, 1.07; 95% CI, 1.04 to 1.10). When the initial response was assessed at 72 h after antimicrobial therapy, the treatment failure rate for the ESBL
-
producing
K. pneumoniae
-infected group was almost twice as high as that of the non-ESBL
-
producing
K. pneumoniae
-infected group (31% versus 17%; OR, 2.19; 95% CI, 0.98 to 4.89). The 21-day mortality rate for all patients was 37% (54 of 147); it was 52% (25 of 48) for patients with ESBL
-
producing
K. pneumoniae
bloodstream infections and 29% (29 of 99) for patients with non-ESBL
-
producing
K. pneumoniae
bloodstream infections (OR, 2.62; 95% CI, 1.28 to 5.35). In summary, this investigation identifies epidemiological characteristics that distinguish ESBL
-
producing
K. pneumoniae
infections from non-ESBL
-
producing
K. pneumoniae
ESBL bloodstream infections.
CMY-16, a Novel Acquired AmpC-Type β-Lactamase of the CMY/LAT Lineage in Multifocal Monophyletic Isolates of
Proteus mirabilis
from Northern Italy
Authors: D'Andrea Marco M. , Nucleo Elisabetta , Luzzaro Francesco , Giani Tommaso , Migliavacca Roberta , Vailati Francesca , Kroumova Vesselina , Pagani Laura , Rossolini Gian Maria
Published: January 2006

We report multifocal detection (four different cities in northern Italy) of
Proteus mirabilis
isolates resistant to both oxyimino- and 7-α-methoxy-cephalosporins and producing a novel acquired AmpC-like β-lactamase. The enzyme, named CMY-16, is a variant of the CMY/LAT lineage, which differs from the closest homologues, CMY-4 and CMY-12, by a single amino acid substitution (A171S or N363S, respectively) and from CMY-2 by two substitutions (A171S and W221R). Expression of the cloned
bla
CMY-16
gene in
Escherichia coli
decreased susceptibility to penicillins, cephalosporins, and aztreonam. Tazobactam was more effective than clavulanate at antagonizing the enzyme activity. Genotyping, by random amplification of polymorphic DNA and pulsed-field gel electrophoresis of genomic DNA digested with SfiI, showed that isolates were clonally related to each other, although not identical. The
bla
CMY-16
gene was not transferable to
E. coli
by conjugation or transformation. In all isolates, it was chromosomally located and inserted in a conserved genetic environment. PCR mapping experiments revealed that the
bla
CMY-16
was flanked by IS
Ecp1
and the
blc
gene, similar to other genes of this lineage from plasmids of
Salmonella enterica
,
Klebsiella
spp., and
E. coli
. Overall, these results revealed multifocal spreading of a CMY-16-producing
P. mirabilis
clone in northern Italy. This finding represents the first report of an acquired AmpC-like β-lactamase in
Proteus mirabilis
from Italy and underscores the emergence of similar resistance determinants in the European setting.
In Vitro Preclinical Testing of Nonoxynol-9 as Potential Anti-Human Immunodeficiency Virus Microbicide: a Retrospective Analysis of Results from Five Laboratories
Authors: Beer Brigitte E. , Doncel Gustavo F. , Krebs Fred C. , Shattock Robin J. , Fletcher Patricia S. , Buckheit Robert W. , Watson Karen , Dezzutti Charlene S. , Cummins James E. , Bromley Ena , Richardson-Harman Nicola , Pallansch Luke A. , Lackman-Smith Carol , Osterling Clay , Mankowski Marie , Miller Shendra R. , Catalone Bradley J. , Welsh Patricia A. , Howett Mary K. , Wigdahl Brian , Turpin Jim A. , Reichelderfer Patricia
Published: January 2006

The first product to be clinically evaluated as a microbicide contained the nonionic surfactant nonoxynol-9 (nonylphenoxypolyethoxyethanol; N-9). Many laboratories have used N-9 as a control compound for microbicide assays. However, no published comparisons of the results among laboratories or attempts to establish standardized protocols for preclinical testing of microbicides have been performed. In this study, we compared results from 127 N-9 toxicity and 72 efficacy assays that were generated in five different laboratories over the last six years and were performed with 14 different cell lines or tissues. Intra-assay reproducibility was measured at two-, three-, and fivefold differences using standard deviations. Interassay reproducibility was assessed using general linear models, and interaction between variables was studied using step-wise regression. The intra-assay reproducibility within the same N-9 concentration, cell type, assay duration, and laboratory was consistent at the twofold level of standard deviations. For interassay reproducibility, cell line, duration of assay, and N-9 concentration were all significant sources of variability (
P
< 0.01). Half-maximal toxicity concentrations for N-9 were similar between laboratories for assays of similar exposure durations, but these similarities decreased with lower test concentrations of N-9. Results for both long (>24 h) and short (<2 h) exposures of cells to N-9 showed variability, while assays with 4 to 8 h of N-9 exposure gave results that were not significantly different. This is the first analysis to compare preclinical N-9 toxicity levels that were obtained by different laboratories using various protocols. This comparative work can be used to develop standardized microbicide testing protocols that will help advance potential microbicides to clinical trials.
Effect of Ribavirin and Glucocorticoid Treatment in a Mouse Model of Human Metapneumovirus Infection
Authors: Hamelin Marie-Ève , Prince Gregory A. , Boivin Guy
Published: January 2006

Human metapneumovirus (hMPV)-infected BALB/c mice were treated with ribavirin (40 mg/kg of body weight twice a day intraperitoneally), corticosterone (0.2 mg/ml in water), or both modalities. Ribavirin significantly decreased both hMPV replication in lungs (by 5 log
10
) and global pulmonary inflammation on day 5 postinfection, whereas glucocorticoids reduced only alveolar and interstitial inflammation, compared to controls.
Antimicrobial Susceptibilities of
Campylobacter jejuni
Isolates from Poultry from Alberta, Canada
Authors: Kos Veronica N. , Keelan Monika , Taylor Diane E.
Published: January 2006

One hundred four isolates of
Campylobacter jejuni
from poultry in Alberta, Canada, collected during 2001 were tested for resistance to 10 antimicrobial agents using agar dilution. This study provides a baseline of resistance profiles and the mechanisms of resistance observed in
C. jejuni
in poultry from Alberta, Canada.
Piperine, a Phytochemical Potentiator of Ciprofloxacin against
Staphylococcus aureus
Authors: Khan Inshad Ali , Mirza Zahid Mehmood , Kumar Ashwani , Verma Vijeshwar , Qazi Ghulam Nabi
Published: January 2006

Piperine, a trans-trans isomer of 1-piperoyl-piperidine, in combination with ciprofloxacin markedly reduced the MICs and mutation prevention concentration of ciprofloxacin for
Staphylococcus aureus
, including methicillin-resistant
S. aureus
. The enhanced accumulation and decreased efflux of ethidium bromide in the wild-type and mutant (CIP
r
-1) strains in the presence of piperine suggest its involvement in the inhibition of bacterial efflux pumps.