bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemokine Production by Buccal Epithelium as a Distinctive Feature of Pediatric Crohn Disease
Authors: Damen Gerard M , Hol Jeroen , de Ruiter Lilian , Bouquet Jan , Sinaasappel Maarten , van der Woude Janneke , Laman Jon D , Hop Wim C. J , Büller Hans A , Escher Johanna C , Nieuwenhuis Edward E. S
Published: February 2006

Objectives:

Inflammatory bowel diseases (IBD) represent an aberrant immune response by the mucosal immune system to luminal bacteria. Because the oral mucosa harbors the first epithelial cells that interact with microorganisms, we assessed the immunologic activity of buccal epithelium in children with IBD and adults with Crohn disease.

Methods:

Buccal epithelial cells were obtained from 17 children and 14 adults with Crohn disease, 18 children with ulcerative colitis, and 40 controls. Cells were cultured with and without microbial stimulation. Chemokine levels were determined in culture supernatants by cytometric bead array and enzyme‐linked immunoabsorbent assay. CXCL‐8 production was studied by immunohistochemical analysis of these cells. CXCL‐8 production by lipopolysaccharide stimulated monocyte‐derived dendritic cells from these patients was determined.

Results:

Compared with controls, pediatric ulcerative colitis patients, and adult Crohn disease patients, only in children with Crohn disease did buccal epithelial cells exhibit enhanced production of CXCL‐8, CXCL‐9, and CXCL‐10. In vitro stimulation with lipopolysaccharide or zymosan resulted in a further increase of chemokine levels only in cells from pediatric Crohn disease patients. CXCL‐8 production by stimulated monocyte‐derived dendritic cells from children with Crohn disease was equal to that of children with ulcerative colitis.

Conclusions:

Buccal epithelium of children with Crohn disease is immunologically active, even in the absence of oral lesions. The enhanced chemokine production is associated with pediatric Crohn disease and appears restricted to cells derived from the epithelial barrier. Assessment of chemokine production by buccal epithelial cells may become a new, rapid, noninvasive test for screening and classification of IBD in children.
Meat as a First Complementary Food for Breastfed Infants: Feasibility and Impact on Zinc Intake and Status
Authors: Krebs Nancy F , Westcott Jamie E , Butler Nancy , Robinson Cordelia , Bell Melanie , Hambidge K Michael
Published: February 2006

Objective:

This study was undertaken to assess the feasibility and effects of consuming either meat or iron‐fortified infant cereal as the first complementary food.

Methods:

Eighty‐eight exclusively breastfed infants were enrolled at 4 months of age and randomized to receive either pureed beef or iron‐fortified infant cereal as the first complementary food, starting after 5 months and continuing until 7 months. Dietary, anthropometric, and developmental data were obtained longitudinally until 12 months, and biomarkers of zinc and iron status were measured at 9 months.

Results:

Mean (±SE) daily zinc intake from complementary foods at 7 months for infants in the meat group was 1.9 ± 0.2 mg, whereas that of the cereal group was 0.6 ± 0.1 mg, which is approximately 25% of the estimated average requirement. Tolerance and acceptance were comparable for the two intervention foods. Increase in head circumference from 7 to 12 months was greater for the meat group, and zinc and protein intakes were predictors of head growth. Biochemical status did not differ by feeding group, but approximately 20% of the infants had low (<60 μg/dL) plasma zinc concentrations, and 30% to 40% had low plasma ferritin concentrations (<12 μg/L). Motor and mental subscales did not differ between groups, but there was a trend for a higher behavior index at 12 months in the meat group.

Conclusions:

Introduction of meat as an early complementary food for exclusively breastfed infants is feasible and was associated with improved zinc intake and potential benefits. The high percentage of infants with biochemical evidence of marginal zinc and iron status suggests that additional investigations of optimal complementary feeding practices for breastfed infants in the United States are warranted.
Management of Fulminating Ulcerative Colitis in Childhood with Chimeric Anti‐CD25 Antibody
Authors: Schwarzer A , Ricciardelli I , Kirkham S , Binnie K , Shah N , Elawad M A , Hill S M , Furman M , Smith V V , Sebire N , Milla P J , Londei M , Lindley K J
Published: February 2006

Fulminating acute ulcerative colitis (UC) is a potentially life threatening medical emergency. Up to 30% of individuals respond poorly to corticosteroids alone and second line medical or surgical therapies are indicated. We describe the successful use of chimeric anti‐CD25 therapy in 4 such children poorly responsive to combined therapy with intravenous steroids and calcineurin inhibitors with a pretreatment predictive risk of colectomy of 85‐100%. Clinical disease activity scores normalized within 72 hours of anti‐CD25 administration and colonic histology provided evidence of mucosal healing within 10‐14 days. None required emergency colectomy. Anti‐CD25 is efficacious in fulminating UC and randomized placebo controlled trials appear indicated.
A Prospective Study Comparing Oral Sodium Phosphate Solution to a Bowel Cleansing Preparation with Nutrition Food Package in Children
Authors: El‐Baba Mohammad F , Padilla Mary , Houston Carmela , Madani Shailender , Lin Chuan‐Hao , Thomas Ronald , Tolia Vasundhara
Published: February 2006

Objective:

The inability of children to comply with bowel preparation regimens can result in inadequate visualization of the colon. This study compares the safety, efficacy, and patient acceptance of a prepackaged diet kit plus a magnesium citrate/bisacodyl bowel cleansing regimen with a clear liquid diet and sodium phosphate solution regimen in children undergoing colonoscopy.

Methods:

Children scheduled for a diagnostic colonoscopy, were randomly assigned to receive a prepackaged diet kit and a magnesium citrate/bisacodyl laxative (group 1), or clear liquids and sodium phosphate solution (group 2). The patients and their parents completed a questionnaire to evaluate acceptance of their assigned regimen before colonoscopy. The endoscopists, blinded to the type of bowel preparation, rated bowel cleansing.

Results:

Sixty two children (28 males, 34 females) with mean age 12.5 years participated. Thirty six and 26 patients were in groups 1 and 2 respectively. Overall cleansing was rated significantly superior in group 1 compared to group 2 as was amount of retained feces (P = .013 for both). The overall frequency of reported side‐effects was lower in group 1 than (83.3%, 30/36) than in group 2 (100.0%, 26/26) (P = 0.03). The preparations were otherwise equivalent in regards to compliance and patient tolerance.

Conclusions:

Although both regimens were comparable in adequacy of colon visualization, preparation tolerance, side effects and compliance profile in this pilot study, the prepackaged diet kit with magnesium citrate/bisacodyl laxative resulted in superior colon cleansing.
Role of Trp140 at subsite −6 on the maltohexaose production of maltohexaose‐producing amylase from alkalophilic Bacillus sp.707
Authors: Kanai Ryuta , Haga Keiko , Akiba Toshihiko , Yamane Kunio , Harata Kazuaki
Published: February 2006

Maltohexaose‐producing amylase (G6‐amylase) from alkalophilic Bacillus sp.707 predominantly produces maltohexaose (G6) in the yield of >30% of the total products from short‐chain amylose (DP = 17). Our previous crystallographic study showed that G6‐amylase has nine subsites, from −6 to +3, and pointed out the importance of the indole moiety of Trp140 in G6 production. G6‐amylase has very low levels of hydrolytic activities for oligosaccharides shorter than maltoheptaose. To elucidate the mechanism underlying G6 production, we determined the crystal structures of the G6‐amylase complexes with G6 and maltopentaose (G5). In the active site of the G6‐amylase/G5 complex, G5 is bound to subsites −6 to −2, while G1 and G6 are found at subsites + 2 and −7 to −2, respectively, in the G6‐amylase/G6 complex. In both structures, the glucosyl residue located at subsite −6 is stacked to the indole moiety of Trp140 within a distance of 4Å. The measurement of the activities of the mutant enzymes when Trp140 was replaced by leucine (W140L) or by tyrosine (W140Y) showed that the G6 production from short‐chain amylose by W140L is lower than that by W140Y or wild‐type enzyme. The face‐to‐face short contact between Trp140 and substrate sugars is suggested to regulate the disposition of the glucosyl residue at subsite −6 and to govern product specificity for G6 production.
The Occipital Cortex in the Blind
Authors: Amedi Amir , Merabet Lotfi B. , Bermpohl Felix , Pascual-Leone Alvaro
Published: February 2006

Studying the brains of blind individuals provides a unique opportunity to investigate how the brain changes and adapts in response to afferent (input) and efferent (output) demands. We discuss evidence suggesting that regions of the brain normally associated with the processing of visual information undergo remarkable dynamic change in response to blindness. These neuroplastic changes implicate not only processing carried out by the remaining senses but also higher cognitive functions such as language and memory. A strong emphasis is placed on evidence obtained from advanced neuroimaging techniques that allow researchers to identify areas of human brain activity, as well as from lesion approaches (both reversible and irreversible) to address the functional relevance and role of these activated areas. A possible mechanism and conceptual framework for these physiological and behavioral changes is proposed.
Music and Cognitive Abilities
Authors: Schellenberg E. Glenn
Published: February 2006

Does music make you smarter? Music listening and music lessons have been claimed to confer intellectual advantages. Any association between music and intellectual functioning would be notable only if the benefits apply reliably to nonmusical abilities and if music is unique in producing the effects. The available evidence indicates that music listening leads to enhanced performance on a variety of cognitive tests, but that such effects are short-term and stem from the impact of music on arousal level and mood, which, in turn, affect cognitive performance; experiences other than music listening have similar effects. Music lessons in childhood tell a different story. They are associated with small but general and long-lasting intellectual benefits that cannot be attributed to obvious confounding variables such as family income and parents' education. The mechanisms underlying this association have yet to be determined.
Hyperalgesia induced by cutaneous freeze injury for testing analgesics in healthy volunteers
Authors: Chassaing Claude , Schmidt Jeannot , Eschalier Alain , Cardot Jean Michel , Dubray Claude
Published: February 2006

Aims

The early phases of the clinical development of new analgesic agents are severely hindered by a lack of reliable sensitive tests based on experimental pain models. The aim of this study was to assess the ability of a localized hyperalgesia model induced by cutaneous freeze injury to evaluate the pharmacodynamic profile of weak analgesic agents in healthy volunteers.

Method and results

Two groups of 24 healthy volunteers were enrolled in controlled, randomized, double‐blind, cross‐over studies. After freeze injury, punctate mechanical pain thresholds (MPT) were measured over three consecutive daily sessions to characterize the induced hyperalgesia and compare the effects of (i) oral ibuprofen and acetaminophen and (ii) oral and topical ibuprofen vs. placebo. The freeze injury model provides two types of hyperalgesia, primary and secondary, stable over 72 h. The MPT values (means; 95% confidence interval) in the primary (38.9 g; 34.3, 43.5) and secondary (82.2 g; 81.4, 88.0) areas of hyperalgesia were different from normal skin (107.5 g; 101.5, 115.2). This model clearly showed the antihyperalgesic effect of both systemic and topical ibuprofen (42.1%; 26.6, 61.2 and 33.8%; 16.4, 51.2 of MPT increase, respectively) but not that of acetaminophen.

Conclusion

Cutaneous freeze injury coupled with a von Frey electronic device to assess the mechanical pain threshold is a convenient model that causes no discomfort. The improved sensitivity and stability of this experimental model of hyperalgesia over three consecutive days make it a useful tool for evaluating the efficacy and detecting the potential sites of action of analgesic agents such as nonsteroidal anti‐inflammatory drugs in healthy human subjects.
Effect of grapefruit juice on the disposition of manidipine enantiomers in healthy subjects
Authors: Uno Tsukasa , Ohkubo Tadashi , Motomura Shigeru , Sugawara Kazunobu
Published: February 2006

Aim

To examine the effect of grapefruit juice, an inhibitor of CYP3A4 in the small intestine, on the disposition of manidipine enantiomers in healthy subjects.

Methods

A randomized cross‐over study with at least a 2‐week wash‐out period was performed. Seven healthy male volunteers received an oral 40‐mg dose of racemic manidipine after an overnight fast with either grapefruit juice (GFJ) or water, as a control study. Plasma concentrations of (S)‐ and (R)‐manidipine were monitored up to 10 h after the dosing.

Results

The plasma concentrations of (S)‐manidipine were significantly higher (P < 0.001) than those of (R)‐manidipine in the control phase with an S/R ratio for the AUC0–∞ of 1.62 (95% confidence interval 1.52, 1.73). GFJ significantly increased Cmax and AUC0–∞ of (S)‐manidipine by 2.4‐fold (P < 0.01) and 2.3‐fold (P < 0.01), respectively, and Cmax and AUC0–∞ of (R)‐manidipine were increased by 3.4‐fold (P < 0.01) and 3.0‐fold (P < 0.01), respectively. There were significant differences (P < 0.01) in GFJ‐mediated percentage increases in Cmax and AUC0–∞ of (S)‐manidipine compared with those of (R)‐manidipine. The S/R ratio for AUC0–∞ was significantly decreased from 1.6 to 1.2 during the GFJ phase (P < 0.01).

Conclusion

These results indicate that the stereoselective disposition of manidipine was altered by GFJ, as an inhibitor of CYP3A4. GFJ appears to affect this metabolic disposal of (R)‐manidipine to a greater extent than that of (S)‐manidipine.
Circulating levels and clinical significance of soluble CD86 in myeloma patients
Authors: Hock B. D. , Drayson M. , Patton W. N. , Taylor K. , Kerr L. , McKenzie J. L. ,   the Working Party on Leukaemia in adults (part of the NCRI Haematological Oncology Clinical Studies Group)
Published: February 2006

Circulating soluble CD86 (sCD86) levels are elevated in a number of leukaemias and are an independent prognostic factor in acute myeloid leukaemia. We investigated the clinical significance of circulating sCD86 in 299 patients from the UK Medical Research Council myeloma VIth trial, where patients received ABCM [adriamycin, carmustine (BCNU), cyclophosphamide, melphalan] either alone or with prednisolone (ABCM + P). Serum levels of sCD86 were significantly elevated (P = 0·0001) in myeloma patients and using the median normal donor level (0·621 ng/ml) as a cut‐off point, 70% of patients had elevated levels (range = 0·015–15·87 ng/ml, median = 1·1 ng/ml). In univariate analysis elevated sCD86 levels were associated with significantly shorter (P < 0·001) survival (median = 22 vs. 51 months) and event‐free survival (median = 14 vs. 31 months) in ABCM + P but not ABCM patients. Multivariate analysis demonstrated that sCD86 was a significant, independent prognostic marker of both overall [risk ratio (RR) = 2·04, P = 0·0006] and event‐free (RR = 1·95, P = 0·0004) survival in ABCM + P patients. In conclusion, this study demonstrated that sCD86 levels are a significant independent prognostic marker in at least some myeloma treatment groups and its biological role and prognostic value should be further investigated.
Carrying capacity and survival strategy for the Pacific bluefin tuna, Thunnus orientalis, in the Western Pacific
Authors: MATSUKAWA YASUO
Published: February 2006

The carrying capacity for the Pacific bluefin tuna at each life stage is estimated and its survival strategy is examined numerically, using a new method to define the hypothetical capacity, the standard population, and the search volumes that are necessary and are feasible for the tuna. The carrying capacity for the adult is estimated at 1–2 × 106 individuals, which corresponds with 5–10% of the hypothetical capacity and is comparable with the maximum levels of the southern and the Atlantic bluefin tuna populations. It is hypothesized semiquantitatively that the migration at each life stage and the remarkable decrement of growth at 120 days and about 40 cm occur as an evolutionary response to population excess over the carrying capacity. It is also hypothesized semiquantitatively that the early larvae have minimal food available in the Subtropical Water and develop the predatory morphology, high growth rate, and high mobility, however, at the expense of a high mortality as an evolutionary response to the tuna spawning in the Subtropical Water. This method may be an available tool to not only investigate the carrying capacity and survival strategy of a specific fish species, but also predict when and in how much abundance the fish species occurs in a specific area of its habitat.
Spatial distribution of the Japanese common squid, Todarodes pacificus, during its northward migration in the western North Pacific Ocean
Authors: KAWABATA ATSUSHI , YATSU AKIHIKO , UENO YASUHIRO , SUYAMA SATOSHI , KURITA YUTAKA
Published: February 2006

The spatial distribution of Todarodes pacificus in and near the Kuroshio/Oyashio Transition Zone during its northward migration was examined by comparative surveys using two types of mid‐water trawl net and supplementary squid jigging from June to July 2000. The vertical and horizontal distribution patterns varied for different body sizes in relation to the oceanographic structure. Todarodes pacificus of 1–20 cm dorsal mantle length (ML) were widely distributed from the coastal waters of Japan to near 162°E longitude, probably due to transport by the Kuroshio Extension (KE). Todarodes pacificus smaller than 10 cm ML were mainly distributed in temperate surface layers at sea surface temperatures (SSTs) >15°C near the KE meander probably because of their poor tolerance to lower temperatures and limited swimming ability. Squid of 10–15 cm ML were distributed in the offshore waters of 10–15°C SST and in the coastal waters of northern Honshu, and underwent diel vertical migrations between the sea surface at night and deeper layers during the daytime. Squid larger than 15 cm ML were distributed in the coastal feeding grounds of northern Honshu and Hokkaido until they began their southward spawning migration. They also underwent diel vertical migrations, but remained deeper at night than the squid of 10–15 cm ML; this migration pattern closely matched that of their main prey such as euphausiids. We concluded that as T. pacificus grow, they shift their distribution range from the temperate surface layer around the KE toward the colder deeper layers, above 5°C, in the Oyashio and coastal areas.
Change in habitat associations and geographic distribution of thorny skate (Amblyraja radiata) in the southern Gulf of St Lawrence: density‐dependent habitat selection or response to environmental change?
Authors: SWAIN D. P. , BENOÎT H. P.
Published: February 2006

We describe changes in the habitat associations and geographic distribution of thorny skate during their feeding season in the southern Gulf of St Lawrence, based on 32 yr of monitoring by a bottom‐trawl survey. In the 1990s, geographic range contracted sharply and distribution shifted into a narrow band of warm deep waters. These changes appeared to reflect altered habitat selection by individual skates, rather than local depletion of the skates that had habitually occupied the vacated areas or a change in the timing of seasonal migrations. Changes in skate distribution coincided with a decline in skate biomass and a cooling of bottom waters. The contraction in the geographic range of skates appeared to be a density‐dependent response, more closely linked to the decline in skate abundance than to the change in environmental conditions. The cause of the shift in habitat associations is less certain. An index of the distribution shift was more strongly correlated with skate biomass than with an index of temperature conditions, and the change in temperature associations is in the direction predicted by density‐dependent bioenergetic considerations. However, the shift into deeper waters is into a depth zone where skate condition is relatively low, contrary to the expectation that fish should be concentrated in optimal habitat at low population size. On the other hand, while the shift into warm deep waters coincided with a cooling of waters at intermediate depths, distribution failed to shift back to the earlier pattern as these waters warmed in the late 1990s.
Assessment of different gutta‐percha brands during the filling of simulated lateral canals
Authors: Gurgel‐Filho E. D. , Feitosa J. P. A. , Gomes B. P. F. A. , Ferraz C. C. R. , Souza‐Filho F. J. , Teixeira F. B.
Published: February 2006

Aim  To compare the ability of five different commercially available gutta‐percha points to fill simulated lateral canals when subjected to warm vertical compaction.

Methodology  Fifty clear plastic teeth with a lateral canal in each third of the root were used. All teeth were filled using warm vertical compaction. Backfilling was completed with a sealer and the same gutta‐percha point used during the apical condensation. After this, they were horizontally sectioned using a diamond disc adapted to a low‐speed saw. The resulting sections were embedded in epoxy resin. The extent of gutta‐percha and sealer filling were measured in each lateral canal using an IMAGE‐PRO 4.0 software system. The voids in each canal were measured using the same system. Data were ranked and analysed using the Kruskal–Wallis statistical test.

Results  The mean percentage of the three lateral canals filled with gutta‐percha and sealer were respectively: Konne (68.23% and 24.50%), Analytic (67.90% and 25.28%), Obtura (63.80% and 29.60%), Tanari (49.42% and 45.86%) and Dentsply (44.60% and 47.05%). There was significantly (P < 0.05) more gutta‐percha in the lateral canal filled with AnalyticTM, ObturaTM and KonneTM points than with TanariTM and DentsplyTM points.

Conclusions  The brand of gutta‐percha cone had an influence on the length of filling within lateral canals. This may be a reflection of the chemical formulation of the gutta‐percha points.
Influence of phase transformation on the torsional and bending properties of nickel–titanium rotary endodontic instruments
Authors: Miyai K. , Ebihara A. , Hayashi Y. , Doi H. , Suda H. , Yoneyama T.
Published: February 2006

Aim  To investigate the relationship between the functional properties and the phase transformation of nickel–titanium endodontic instruments.

Methodology  Five types of rotary nickel–titanium endodontic instruments with a 0.30 mm diameter tip (EndoWave, HERO 642, K3, ProFile.06, and ProTaper) were selected to investigate torsional and bending properties, and phase transformation behaviour. A torsional test was performed according to ISO publication 3630‐1, and maximum torque and angular deflection at fracture were measured. Bending load of the instruments was measured in a cantilever‐bending test at 37 °C with the maximum deflection of 4.0 mm. A stainless steel K‐file was used for reference. Phase transformation behaviour was measured by differential scanning calorimetry (DSC). From the DSC curve, transformation temperatures were calculated. Data were analysed by anova and the Tukey–Kramer's test.

Results  The maximum torsional torque values of HERO, K3 and ProTaper were significantly higher (P < 0.05) than those of EndoWave, ProFile and K‐file. The K‐files had the lowest torque value. Angular deflection at fracture was significantly higher (P < 0.05) for K‐files than that for any nickel–titanium instrument. The bending load values of HERO and K3 were significantly higher (P < 0.05) than those of EndoWave, ProFile, ProTaper and K‐file. The K‐files had the lowest load value, although residual deflection remained. The transformation temperatures of HERO and K3 were significantly lower (P < 0.05) than those of EndoWave, ProFile and ProTaper.

Conclusions  The functional properties of nickel–titanium endodontic instruments, especially their flexible bending load level, were closely related to the transformation behaviour of the alloys.
Evaluation of the accuracy of three electronic apex locators using glass tubules
Authors: Fan W. , Fan B. , Gutmann J. L. , Bian Z. , Fan M. W.
Published: February 2006

Aim  To evaluate the accuracy of three different electronic apex locators (EALs) using glass tubules.

Methodology  Forty‐eight glass tubules with different diameters and an agar model were used to mimic root canals. A size 15 stainless steel K‐file was used as the measuring electrode. The Root ZX, Propex and Neosono Ultima EZ were used to measure the tubule length with tubules dry, or filled with 0.9% NaCl, 3% H2O2, 2.5% NaOCl or 17% EDTA. The distance between the real length (RL) and measured length (ML) of the tubules was recorded. The range of RL ± 0.5 mm and RL ± 1 mm was used to evaluate the accuracy of the EALs. Results were subject to correlation analysis and Friedman's test.

Results  In dry tubules, the accuracy of Root ZX was 75–91.7% for RL ± 0.5 mm and 100% for RL ± 1 mm, whilst the measurements of the other two EALs were all within the RL ± 0.5 mm. No influence from the increase in tubule diameter on the accuracy of all three EALs was observed in dry tubules. In tubules filled with electrolyte, the accuracy of the Root ZX decreased as tubule diameter increased (Rd > 0, P < 0.05). The RL–ML distance recorded by Propex was inversely related to the tubule diameter (Rd < 0, P < 0.05). The accuracy of Propex was 75–100% for RL ± 0.5 mm and 100% for RL ± 0.5 mm when the tubule diameter was not more than 0.80 mm, but decreased in tubules with diameter over 0.80 mm and filled with 2.5% NaOCl or 17% EDTA. Nearly, all the measurements (except for six tubules) using Neosono Ultima EZ were within 1 mm shorter than RL despite the contents in tubules and the increase of tubule diameter.

Conclusions  The accuracy of the Root ZX decreased as the tubule diameter increased when tubules were filled with electrolytes. The electrolytes in the tubules decreased the accuracy of Propex when the tubule diameter was large. The electrolytes in tubules and tubule diameter had no influence on the accuracy of Neosono Ultima EZ. The Propex and Neosono Ultima EZ were more accurate than the Root ZX under various conditions in this laboratory study.
The effect of pre‐soaking and time in the ultrasonic cleaner on the cleanliness of sterilized endodontic files
Authors: Aasim S. A. , Mellor A. C. , Qualtrough A. J. E.
Published: February 2006

Aims  To assess whether pre‐soaking files in an enzymatic cleaner prior to ultrasonic cleaning had any effect on cleanliness and also to assess the effect of the time that endodontic files spend in an ultrasonic bath prior to sterilization on their overall cleanliness.

Methodology  Twenty root canals in a total of ten patients were cleaned and shaped using conventional techniques. Following use, some of the files were pre‐soaked and then ultrasonically cleaned for either 5, 10, 30 or 60 min. Other files had no pre‐soaking and were then ultrasonically cleaned. There were two control groups, one where the files were pre‐soaked and not ultrasonically cleaned and the other where the files were neither pre‐soaked nor ultrasonically cleaned. All files were then subjected to a standard packing and autoclaving process. Following autoclaving, the files were examined using a light microscope at a magnification of 40×. The cutting section of each file was divided into two parts, the tip and the shaft, for visualization under the microscope. Any debris or cement on the files was scored using a modification of the scale used by Smith et al. (Journal of Hospital Infection, 51, 2002, 233). The data were analysed using one‐way analysis of variance.

Results  Pre‐soaking had no significant effect on the cleanliness of the files (P = 0.18 at the tip, P = 0.93 at the shaft). Ultrasonic cleaning had a significant effect on the cleanliness of the files (P < 0.00) but there was not a linear relationship between cleanliness and the ultrasonic cleaning time. There was little benefit in extending the ultrasonic cleaning time beyond 5 min. Calcium hydroxide deposits on two files were resistant to ultrasonic cleaning.

Conclusions  There is no benefit in pre‐soaking endodontic files prior to ultrasonic cleaning. The optimum time for ultrasonic cleaning was between 5 and 10 min. Further ultrasonic exposure, up to 60 min, did not improve cleanliness. Although a majority of files were free from debris following ultrasonic cleaning, a substantial minority still retained debris. This supports the case for endodontic files being single‐use only.
Spatial heterogeneity, land use and conservation in the cerrado region of Brazil
Authors: Silva J. F. , Fariñas M. R. , Felfili J. M. , Klink C. A.
Published: February 2006

Aim  This paper presents a spatial classification of the environmental and ecological diversity of the cerrado region of Brazil, as well as an appraisal of the levels of conversion to agriculture and of the extent of land protection.

Location  The cerrado region of Brazil, located in the centre of Brazil, occupies c. 2.5 million square kilometres. Our study area represents roughly 85% of the total. This ecologically heterogeneous region is dominated by savannas, but also contains several types of forests and xerophytic communities that often form mosaics with the savannas. Its high biodiversity is seriously threatened by the accelerated process of conversion to agriculture and a deficiency in the extent and the representativeness of protected areas.

Methods  We selected 124 land systems from a previous study of the lowlands of South America. The maps were digitized and 41 parameters, where environmental information was available, were used to build a matrix. A cluster analysis was then performed and the results used to classify the land systems into units at two scales. The larger units, characterized by the dominant landform and vegetation, were considered as landscape units. Within each of these, smaller units called ecological units were defined by the physiognomy and phenology of the dominant vegetation, topography and drainage. Using GIS, we mapped the resulting ecological units and incorporated the information on land use from the municipal agricultural census of 1996. In addition, data on the extent of protected land units was used to assess the status of land protection in each ecological unit.

Results  Five landscape units and 15 ecological units were identified, mapped and explained. These units were not continuous but were represented by disjunct patches located in different parts of the study region. Brief descriptions are given including the geographical locations and dominant ecological features. They also include the extent of land conversion to agriculture (1996 census figures) in each of the various patches as well as the number and area of units of conservation.

Main conclusions  The high level of land conversion to agriculture is a major threat to the conservation of the remarkable biodiversity of the cerrado region. This, together with the poor status of land protection, represents the major environmental problem facing this region. However, the fact that areas with similar general ecological conditions have a disjunct distribution is important for conservation purposes, even though the details of floristic similarities and biogeographic influences have still to be worked out. Our detailed spatial classification has made this disjunction clearly apparent and has allowed us to map ecologically similar areas accurately. This allows the evaluation of the status of these areas in terms of land use and land protection and may be used in the design of conservation strategies.
Nitrous oxide fluxes from savanna (miombo) woodlands in Zimbabwe
Authors: Rees Robert M. , Wuta Menas , Furley Peter A. , Li Changsheng
Published: February 2006

Aim  We test the hypothesis that land use and climate are important controls of nitrous oxide (N2O) emissions from savanna ecosystems, and that these emissions can be represented by a mechanistic model of carbon (C) and nitrogen (N) transformations.

Location  Miombo woodlands in Zimbabwe are part of widespread woody savanna formations in southern and central Africa that cover more than 2.7 million km2. The rainfall in this region is around 800 mm and is concentrated in the period between November and March.

Methods  Losses of N2O were measured along transects in two field areas using static chambers over a period of 1 year. The vegetation in both areas was dominated by Julbernardia globiflora and Brachystegia spiciformis, but had differing management systems (burned and unburned), soil properties and site characteristics (slope and drainage). The effects of simulated rainfall and fertilizer additions were studied in laboratory incubations.

Results  Patterns of N2O emissions were strongly linked to rainfall. The highest fluxes at both sites were measured within 18 days of the onset of the first rains in November, with fluxes of up to 42 μg N m−2 h−1. During the dry season, fluxes were lower, but a large proportion (R2 values between 0.8 and 0.95, P < 0.001) of the N2O flux could be predicted by variations in soil moisture. Soil columns were set up in the laboratory to which simulated rainwater was added, and the amounts and timing of rainwater addition were varied. Losses of N2O were highest within the first week of the laboratory study. Altering the amount of rainwater addition did not significantly affect N2O loss; however, a continuous addition of water resulted in higher losses of N2O (up to 79 μg N m−2 h−1) than periodic addition of the same amount. A model (denitrification–decomposition) was used to simulate N2O release over a 12 month period, using meteorological data recorded in the vicinity of the field site. The simulations and field data suggest that nitrification was the main process responsible for N2O release during the dry season but that denitrification was more important during the wet season.

Main conclusions  The release of N2O from dryland savannas was shown to constitute an important nutrient flux, and emissions were strongly linked to patterns of rainfall; however, there was evidence to suggest that the magnitude of fluxes is also influenced locally by differences in soil organic matter concentration and drainage.
Productivity and carbon fluxes of tropical savannas
Authors: Grace John , José José San , Meir Patrick , Miranda Heloisa S. , Montes Ruben A.
Published: February 2006

Aim (1) To estimate the local and global magnitude of carbon fluxes between savanna and the atmosphere, and to suggest the significance of savannas in the global carbon cycle. (2) To suggest the extent to which protection of savannas could contribute to a global carbon sequestration initiative.

Location Tropical savanna ecosystems in Africa, Australia, India and South America.

Methods A literature search was carried out using the ISI Web of Knowledge, and a compilation of extra data was obtained from other literature, including national reports accessed through the personal collections of the authors. Savanna is here defined as any tropical ecosystem containing grasses, including woodland and grassland types. From these data it was possible to estimate the fluxes of carbon dioxide between the entire savanna biome on a global scale.

Results Tropical savannas can be remarkably productive, with a net primary productivity that ranges from 1 to 12 t C ha−1 year−1. The lower values are found in the arid and semi‐arid savannas occurring in extensive regions of Africa, Australia and South America. The global average of the cases reviewed here was 7.2 t C ha−1 year−1. The carbon sequestration rate (net ecosystem productivity) may average 0.14 t C ha−1 year−1or 0.39 Gt C year−1. If savannas were to be protected from fire and grazing, most of them would accumulate substantial carbon and the sink would be larger. Savannas are under anthropogenic pressure, but this has been much less publicized than deforestation in the rain forest biome. The rate of loss is not well established, but may exceed 1% per year, approximately twice as fast as that of rain forests. Globally, this is likely to constitute a flux to the atmosphere that is at least as large as that arising from deforestation of the rain forest.

Main conclusions The current rate of loss impacts appreciably on the global carbon balance. There is considerable scope for using many of the savannas as sites for carbon sequestration, by simply protecting them from burning and grazing, and permitting them to increase in stature and carbon content over periods of several decades.
Structural response of Caribbean dry forests to hurricane winds: a case study from Guánica Forest, Puerto Rico
Authors: Van Bloem Skip J. , Lugo Ariel E. , Murphy Peter G.
Published: February 2006

Aim  Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple‐stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes, so wind may also influence forest stature. Furthermore, these forests also tend to grow on soils with low amounts of available phosphorus, which may also influence structure. The objective of this study was to assess the role of high winds in structuring dry forest, and to determine whether soil nutrient pools influence forest response following hurricane disturbance.

Location  Guánica Forest, Puerto Rico.

Methods  Over 2000 stems in five plots were sampled for hurricane effects within 1 week after Hurricane Georges impacted field sites in 1998. Sprout initiation, growth, and mortality were analysed for 1407 stems for 2 years after the hurricane. Soil nutrient pools were measured at the base of 456 stems to assess association between nutrients and sprout dynamics.

Results  Direct effects of the hurricane were minimal, with stem mortality at < 2% and structural damage to stems at 13%, although damage was biased toward stems of larger diameter. Sprouting response was high – over 10 times as many trees had sprouts after the hurricane as before. The number of sprouts on a stem also increased significantly. Sprouting was common on stems that only suffered defoliation or had no visible effects from the hurricane. Sprout survival after 2 years was also high (> 86%). Soil nutrient pools had little effect on forest response as a whole, but phosphorus supply did influence sprout dynamics on four of the more common tree species.

Main conclusions  Hurricanes are able to influence Caribbean tropical dry forest structure by reducing average stem diameter and basal area and generating significant sprouting responses. New sprouts, with ongoing survival, will maintain the high frequency of multi‐stemmed trees found in this region. Sprouting is not limited to damaged stems, indicating that trees are responding to other aspects of high winds, such as short‐term gravitational displacement or sway. Soil nutrients play a secondary role in sprouting dynamics of a subset of species. The short, shrubby forest structure common to the Caribbean can arise naturally as a response to hurricane winds.
Effect of selective logging on forest structure and nutrient cycling in a seasonally dry Brazilian Atlantic forest
Authors: Villela Dora Maria , Nascimento Marcelo T. , de Aragão Luiz Eduardo O. C. , Da Gama Deborah M.
Published: February 2006

Aim  The Brazilian Atlantic forest covers c. 10% of its original extent, and some areas are still being logged. Although several ecological studies in Atlantic forest have been published over the past two to three decades, there has been little research on forest dynamics and there is a particular lack of information on the effects of disturbance. The aim of the present study was to assess the impact of selective logging on forest structure, floristic composition soil nutrients, litterfall and litter layer in a seasonally dry Atlantic forest.

Location  The Mata do Carvão is located in the Guaxindiba Ecological Reserve in São Francisco do ltabapoana district (21°24′ S, 41°04′ W), Rio de Janeiro, Brazil.

Methods  Four plots (50 × 50 m) were set up in 1995 in each of two stands: unlogged and logged. In each plot, all trees ≥ 10 cm d.b.h. were enumerated, identified and measured. Vouchers were lodged at UENF Herbarium. Five surface soil samples were collected in each plot in the dry season (in October 1995). Litterfall was collected in eight traps (0.50 m2) in each plot over a year from 14 November 1995 to 11 November 1996. The litter layer was sampled in eight quadrats (0.25 m2) in each plot in the dry and wet seasons. Soils were air‐dried, sieved, and chemically analysed. The litter was dried (80 °C), sorted into six fractions, weighed and bulked samples analysed for nutrients.

Results  Forest stands did not differ in stem density and total basal area, with a total of 1137 individuals sampled in 1996 (564 unlogged and 573 logged), and a total basal area of 15 m2 (unlogged) and 13.0 m2 (logged). However, unlogged stands had more large trees (≥ 30 cm in d.b.h.) and greater mean canopy height. Among the families, Rutaceae and Leguminosae were the most abundant families in both sites, although the Rutaceae had a higher density in unlogged and Leguminosae in the logged stand. The species diversity index was similar between stands. Late‐successional species, such as Metrodorea nigra var. brevifolia and Paratecoma peroba, were less abundant in the logged stand. Selective logging did not affect nutrient concentrations in the soil or in the litter. However, quantities of the nutrients in the total litterfall and in the leaf litterfall and litter layer were higher in unlogged than in logged stands, mainly as a result of fallen M. nigra leaves. Metrodorea nigra was considered a key species in the nutrients dynamics in Carvão forest.

Main conclusions  Despite the fact that effects on tree diversity and soil nutrients were not clear, selective logging in this Atlantic forest altered canopy structure, increased the relative abundance of some early‐secondary species and decreased the litter input and stock of nutrients. Detailed information on the influence of logging on the distribution and structure of plant populations and in nutrient processes is fundamental for a sustainable logging system to be developed.
Anabolic Steroids: A Fatal Attraction?
Authors: Wood Ruth I
Published: February 2006

Anabolic‐androgenic steroids (AAS) are widely abused, but the potential for dependence and addiction remains unclear. Recent studies from our laboratory have shown that male and female hamsters will voluntarily self‐administer testosterone and other AAS. Furthermore, we have observed fatal androgen overdose during self‐administration. This suggests that AAS are potentially addictive, independent of their effects on muscle mass or athletic performance.
Comparison of curved canals preparations using profile, GT and Hero 642 rotary files
Authors: GARIP Y. , GENÇOĞLU N.
Published: February 2006

summary  This study compared preparations of curved canals, using Profile, GT file and Hero 642 rotary files. A total of 30 mesiobuccal canals of extracted first and second mandibular molars were used in this study. The teeth were embedded in resin and a pre‐operative radiograph was taken. The specimens were then randomly divided into three instrument groups. Pre‐ and post‐instrumentation radiographic images were scanned and superimposed using the visi cad/cam program. At nine horizontal sections at 1 mm increments from the apex, it calculated pre‐ and post‐instrumentation cross sectional areas (mm2) and enlargements to the inner aspect and outer aspects (mm). A Kruskal–Wallis test found no statistical difference among the groups in terms of total areas removed by each instrument (P > 0·05). It also found no significant difference in any group between the total of the inner and outer enlargements (P > 0·05). However the GT file removed significantly more material from the outer side of the canal than the inside at sections 3–5, and the Hero removed significantly more material from the outer side at sections 7–9 (P < 0·05). All instruments produced preparations that maintained original canal curvatures.
Effect of adhesive systems associated with resin‐modified glass ionomer cements
Authors: WANG L. , SAKAI V. T. , KAWAI E. S. , BUZALAF M. A. R. , ATTA M. T.
Published: February 2006

summary  The bonding of resin‐modified glass ionomer cements to dentin remains a challenge in clinical routine. In an attempt to improve this property, different materials and techniques have been proposed. This study investigated the shear bond strength of resin‐modified glass ionomer cements (Vitremer, 3M/ESPE and Fuji II LC Improved, GC) to human dentin using two one‐bottle adhesive systems (Prime & Bond 2·1, Dentsply and Single Bond, 3M/ESPE). The restored specimens were stored in deionized water for 24 h at 37 ± 1 °C, and then the bonded surfaces were tested in shear strength using a Universal testing machine at a crosshead speed of 0·5 mm min−1. Bond strength means were recorded and failure modes were assessed with a stereomicroscope at 40× magnification. Data were submitted to two‐way anova and multiple comparisons were performed using a Tukey statistical test (P < 0·05). Fuji II LC Improved yielded higher bond strength (P < 0·05) than Vitremer in all experimental conditions. No statistically significant differences (P > 0·05) were observed among the proposed dentin surface treatments, although a slight decrease in bond strength was observed when phosphoric acid was used alone. Bond strengths of the resin‐modified glass ionomer cements to dentin seemed to be more material‐dependent than surface treatment‐dependent. It may be concluded that the one‐bottle adhesive systems tested in this study did not improve the bond strength of the resin‐modified glass ionomer cements to dentin.
Individual difference in the number of chewing strokes and its determinant factors
Authors: UEDA T. , SAKURAI K. , SUGIYAMA T.
Published: February 2006

summary  This study was carried out to clarify the distribution and individual variation of the number of chewing strokes before last swallowing (NCS), as well as to assess the factors that affect NCS, when dentulous adults masticate the same type of food. NCS was measured in 75 dentulous adults using gummy candies. Measurements were repeated five times to obtain the average and variation. Moreover, the correlation of NCS with various physiological factors (lateral width and vertical distance of chewing loop, angle of opening and closing path, opening and closing time, occlusal time, masticatory performance, number of occlusal contact points, occlusal contact area, occlusal force, flow rate of whole saliva and viscosity of whole saliva) and 28 personality factors were analysed by both of the single variate analysis and the multivariate analysis. The results showed that the average NCS was 41·0 ± 16·0, and the coefficient of variation was 0·090 ± 0·040. Additionally, the correlation between NCS and each factor was investigated, and found that any of these factors did not function as a single determinant for NCS. Following, determinant factors were further examined by the stepwise method of linear multiple regression analysis. From these analysis we found that when opening and closing time and four personality factors were combined, they were significantly involved in determining NCS (P < 0·01). Therefore, we conclude that individual NCS until last swallowing is not determined by a sole, specific physiological factor but is affected by multiple factors including personality.