bluuebunny/crossref_metadata_2025_split huggingface dataset:
Four years of clinical experience with an adverse reaction unit for dental biomaterials
Authors: Vamnes Jan Sverre , Lygre Gunvor Bentung , Grönningsæter Arne Geir , Gjerdet Nils Roar 
Published: April 2004

Abstract  – Objectives:  We describe the function of, and results from, the Norwegian National Dental Biomaterials Adverse Reaction Unit after 4 years of activity from 1993 to 1997.Methods:  During this period of time, 296 patients were examined at the unit, which is located at the Dental School, University of Bergen. The most prevalent age group was 40–49 years, and 70% were women. Dental amalgam was the primary reason for referral to the unit for nearly 85% of the patients, followed by metals in crowns and bridges (11%). Materials in removable dentures, resin‐based filling materials and cements, endodontic materials, and others, including temporary materials, were also involved. Nearly all (96%) patients reported general subjective symptoms, such as muscle and joint pain, fatigue, and memory problems. Complaints involving the orofacial region (lips, face, temporomandibular joint) and intraoral subjective symptoms were also common.Results:  Of the patients who were patch tested with substances in dental materials, 23% were positive to gold, 28% to nickel, 14% to cobalt, 9% to palladium, 6% to mercury, and 8% to one or more components of resin‐based materials. Mercury concentrations in blood and urine were statistically higher in the patients with amalgam fillings compared with those without.Conclusions:  Generally, we could not establish a straightforward cause‐and‐effect relationship between the presence of dental biomaterials and general symptoms. Twenty patients were advised to replace restorative materials because of contact lesions. Another 20 patients were recommended replacement of materials because of allergy verified with positive patch tests. The complex nature of most of the reactions requires a multidisciplinary approach to the care taking of patients who are concerned about reactions from dental materials, particularly amalgam.
Survival, movement, and resource use of the butterfly Parnassius clodius
Authors: Auckland Julia N. , Debinski Diane M. , Clark William R. 
Published: April 2004

Abstract.  1. A mark–recapture study was conducted on the American Apollo butterfly Parnassius clodius Menetries during three field seasons (1998–2000) to examine its movement patterns over the course of a season within a sagebrush meadow in Grand Teton National Park, Wyoming, U.S.A. The study examined how resources affected butterfly distribution patterns and used mark–recapture data to gain insight into movement differences between sexes and over time.2. The average straight‐line movement of P. clodius was 202 m day−1, adjusted for sampling effort at different distances. Movement estimates in all 3 years were highly correlated with the average distance between plots sampled.3. Butterfly abundance was correlated positively with per cent cover of its host plant Dicentra uniflora, but this relationship decreased in importance during the peak of the flight period when individuals may be more interested in finding mates. There was a weak, positive correlation between butterfly abundance and the abundance of its primary nectar source, Eriogonum umbellatum in 1999, but no relationship in 2000.4. Survival, recapture, and transition probabilities were estimated using open population, capture–recapture models. Survival and recapture probability decreased over the course of each season, while the probability of moving between plots increased. Recapture probability was significantly lower for females than for males among all 3 years, but there was no difference between the sexes in survival rate.
Barley exposed to aerial allelopathy from thistles (Cirsium spp.) becomes less acceptable to aphids
Authors: Glinwood Robert , Ninkovic Velemir , Pettersson Jan , Ahmed Elham 
Published: April 2004

Abstract.  1. Recent studies have shown that plant–plant interaction via chemicals (allelopathy) can affect insects. Here the effects on aphid acceptance of barley after exposure to volatiles and root exudates from two common weeds, the thistles Cirsium arvense and Cirsium vulgare, were investigated.2. Settling by bird cherry‐oat aphid, Rhopalosiphum padi, was significantly reduced on barley plants that had been exposed to volatiles from Cirsium species for 5 days. Settling by Sitobion avenae was also reduced on Cirsium‐exposed plants, whereas settling by Metopolophium dirhodum was not.3. In olfactometer tests, Cirsium‐exposed barley was significantly less attractive to R. padi than was unexposed barley, indicating that exposure causes a change in the volatile profile of barley.4. Exposure of barley to root exudates from Cirsium species had no effect on R. padi settling.5. The results lend weight to the theory that the effects of plant–plant allelopathy can extend to higher trophic levels.
Behaviour and growth of dragonfly larvae along a permanent to temporary water habitat gradient
Authors: Johansson Frank , Suhling Frank 
Published: April 2004

Abstract. 1. Freshwaters form a gradient from small temporary waters to large permanent waters. Identifying and examining traits that restrict the distribution of species along this gradient are crucial to the understanding of community structure in these habitats.2. Using dragonfly larvae species, differences in traits important for growth and survival were studied.3. The traits were studied in a series of laboratory experiments using two pairs of dragonfly species that coexist in the Namibian semi‐desert. One species pair was from the most temporary part of the water permanence gradient and the other species pair from an intermediate part of the gradient.4. As predicted, activity, capture rate, and growth rate were significantly greater in the two temporary water species. Contrary to the prediction made in the work reported here, species differences in microhabitat selection were not related to the species' habitat origin. Cannibalism did not differ between species.5. The results lend support to the hypothesis that selection has favoured certain combinations of trait values and that these traits are important for a successful life in temporary and permanent waters.
Discrimination of Normal Gastric Mucosa from Helicobacter pylori Gastritis using Standard Endoscopes and a Single Observation Site: Studies in Children and Young Adults
Authors: Nakayama Yoshiko , Horiuchi Akira , Kumagai Toshiko , Kubota Seiko , Kobayashi Motohiro , Sano Kenji , Ota Hiroyoshi 
Published: April 2004

ABSTRACTBackground.  In the Helicobacter pylori‐negative normal stomach, collecting venules are visible in the gastric corpus as numerous minute points. This finding has been termed ‘regular arrangement of collecting venules’ (RAC). The aim of the present study was to investigate the reliability of the presence of the RAC pattern for discrimination of normal gastric mucosa from H. pylori gastritis in pediatric patients.Methods.  Fifty‐two consecutive children, adolescents and young adults (male:female 24 : 28; median age 15 years, range 8–29 years) referred for endoscopy and assessed for H. pylori infection were prospectively studied. The lower lesser curvature of the corpus near the incisura was evaluated for the RAC pattern using a standard endoscope with the tip close to, but not in contact with, the gastric surface. Gastric biopsies were taken after the endoscopic observation.Results.  In all the 29 RAC‐positive patients, active H. pylori gastritis was absent, whereas H. pylori gastritis was found in 20 of 23 RAC‐negative patients (86.9%).Conclusions.  Identification of the RAC pattern at the lower lesser curvature of the corpus using close observation with a standard endoscope proved to be an effective and practical marker to discriminate normal histology from H. pylori gastritis among both children and young adults. Absence of the RAC pattern should prompt gastric mucosal biopsies despite otherwise normal‐appearing gastric mucosa.
Effect of Helicobacter pylori Infection on Gastric Acid Secretion and Meal‐Stimulated Serum Gastrin in Children
Authors: Kato Seiichi , Ozawa Kyoko , Koike Tomoyuki , Sekine Hitoshi , Ohara Shuichi , Minoura Takanori , Iinuma Kazuie 
Published: April 2004

ABSTRACTBackground.  Comparative studies of gastric acid secretion in children related to Helicobacter pylori infection are lacking. The purpose of this study was to compare acid secretion and meal‐stimulated gastrin in relation to H. pylori infection among pediatric patients.Materials and Methods.  Thirty‐six children aged 10–17 years (17 with H. pylori infection) undergoing diagnostic endoscopy participated in the study. Diagnoses included gastritis only (n = 23), duodenal ulcer (n = 5) and normal histology (n = 8). Gastric acid output was studied using the endoscopic gastric secretion test before and 2–3 months after H. pylori eradication. Meal‐stimulated serum gastrin response was assessed before and 12 months after eradication.Results.  H. pylori gastritis was typically antrum‐predominant. Acid secretion was greater in H. pylori‐positive patients with duodenal ulcer than in gastritis‐only patients or controls [mean ± standard error (SE): 6.56 ± 1.4, 3.11 ± 0.4 and 2.65 ± 0.2 mEq/10 minutes, respectively; p < .001]. Stimulated acid secretion was higher in H. pylori‐positive boys than girls (5.0 ± 0.8 vs. 2.51 ± 0.4 mEq/10 minutes, respectively; p < .05). Stimulated acid secretion pre‐ and post‐H. pylori eradication was similar (5.47 ± 0.8 vs. 4.67 ± 0.9 mEq/10 minutes, respectively; p = .21). Increased basal and meal‐stimulated gastrin release reversed following H. pylori eradication (e.g. basal from 134 to 46 pg/ml, p < .001 and peak from 544 to 133 pg/ml, p < .05).Conclusions.  H. pylori infection in children is associated with a marked but reversible increase in meal‐stimulated serum gastrin release. Gastric acid hypersecretion in duodenal ulcer remains after H. pylori eradication, suggesting that the host factor plays a critical role in outcome of the infection.
Determinants of Helicobacter pylori Seroprevalence in Mexican Adolescents
Authors: Constanza Camargo M. , Eduardo Lazcano‐Ponce , Javier Torres , Eduardo Velasco‐Mondragón , Manuel Quiterio , Pelayo Correa 
Published: April 2004

ABSTRACTBackground.  Helicobacter pylori infection is one of the most common human infections and is considered to play an etiologic role in several gastroduodenal diseases. In this study we determined the H. pylori seroprevalence among adolescents in Morelos, Mexico, and explored the association between seroprevalence and socioeconomic, dietary and lifestyle variables.Materials and Methods.  A cross‐sectional study was conducted in 5861 Mexican subjects aged 11–21 years. H. pylori infection was determined by an enzyme‐linked immunosorbent assay previously validated in Mexico. A self‐administered questionnaire was used to collect information on sociodemographic factors, housing, living conditions and food consumption. Multivariate logistic regression methods were used to obtain odds ratios and 95% confidence intervals.Results.  The overall H. pylori seroprevalence was 47.6%; 40.6% in preadolescents (11–14 years), 48.6% in adolescents (15–17 years), and 59.8% in young adults (18–24 years). A positive association was found between age and H. pylori seroprevalence. Inverse associations were found for availability of drinking water, sewerage, and home appliances at the time of the subject's birth, a proxy variable of socioeconomic status. Intake of milk products and total fats was positively associated with infection.Conclusions.  This large seroprevalence study showed that H. pylori infection is frequent among adolescents in Mexico. An early acquisition of infection is indirectly suggested. Some variables denoting low socioeconomic status were inversely associated with H. pylori seroprevalence. Associations with intake of milk products and total fats suggest new hypotheses in this field of research.
Detection of Helicobacter pylori DNA in Feces and Saliva by Polymerase Chain Reaction: a Review
Authors: Kabir Shahjahan 
Published: April 2004

ABSTRACTThe polymerase chain reaction (PCR), known for its high sensitivity and specificity, has been used for the detection of Helicobacter pylori DNA in bodily materials such as feces and saliva. Since fecal specimens contain PCR inhibitors, DNA before PCR amplification has been purified using various biochemical, immunological and physical pre‐PCR steps. Several PCR protocols, differing from each other in the selection of genomic targets and primers, have produced varying degrees of specificity and sensitivity in detecting H. pylori DNA. PCR identified antimicrobial resistance of H. pylori in feces. It also detected virulence factor genes such as the cytotoxin‐associated gene (cagA) and vacuolating cytotoxin gene (vacA) in feces and saliva. While the cagA gene was detected in 50–60% of fecal specimens, it was found in 25% of salivary specimens from patients. There was considerable variation in the detection rate of H. pylori DNA in salivary samples. The detection rate in saliva with the most effective primer pair was lower than that observed in feces, making saliva a less suitable specimen for the diagnosis of H. pylori infection. There is controversy regarding the permanent presence of H. pylori in saliva. Whether the salivary and gastric specimens of an individual harbor identical or different strains has not been resolved. PCR cannot distinguish between living and dead organisms. However, it can offer quick results on fecal and salivary specimens, which may contain fastidious and slow‐growing H. pylori in low numbers.
Rapid Combined Characterization of Microorganism and Host Genotypes using a Single Technology
Authors: Hjalmarsson Sandra , Alderborn Anders , Fock Caroline , Muldin Ingrid , Kling Helene , Uhlén Mathias , Engstrand Lars 
Published: April 2004

ABSTRACTBackground.  Genetic information is becoming increasingly important in diagnosis and prognosis of infectious diseases. In this study we investigated the possibility of using a single technology, the Pyrosequencing™ technology (Biotage AB, Uppsala, Sweden), to gather several kinds of important genetic information from the human pathogen Helicobacter pylori, as well as from the carrier of the H. pylori infection.Materials and Methods.  DNA from 87 clinical isolates of H. pylori, 50 isolates from H. pylori‐infected transgenic mice and nine gastric biopsies from H. pylori‐infected patients was analyzed for targets in the 16S rRNA, 23S rRNA and cytotoxin associated gene A (cagA) genes to determine species identity, clarithromycin susceptibility and virulence level, respectively. In addition, three single nucleotide polymorphisms in the human interleukin‐1B (IL‐1B) gene, reported to affect the risk of developing gastric cancer, were analyzed in the gastric biopsy samples.Results.  All DNA targets were processed and analyzed in parallel, enabling convenient genetic characterization of both pathogen and host. All genotypes were easily and accurately assigned. In the 16S rRNA analysis, 99.83% of the bases were correctly called.Conclusions.  We conclude that genetic analysis using Pyrosequencing™ technology was nonlaborious, and gave highly accurate data for different kinds of target. We therefore believe that this technology has the potential to complement or in the future substitute the time‐consuming traditional microbial identification and typing methods, as well as enabling rapid typing of relevant host genetic markers.
Helicobacter pylori Infection Negatively Influences Pregnancy Outcome in a Mouse Model
Authors: Rossi Giacomo , Romagnoli Stefano , Lauretti Laura , Pancotto Laura , Taccini Ennio , Rappuoli Rino , Del Giudice Giuseppe , Ruggiero Paolo 
Published: April 2004

ABSTRACTBackground.  Helicobacter pylori infects the human stomach, causing gastritis, peptic ulcer, and gastric cancer. H. pylori infection has also been related to extra‐gastric disorders. We investigated whether H. pylori infection can influence pregnancy in a murine model.Methods.  Female CD1 mice were infected with the H. pylori SPM326 strain before mating, and then assessed throughout pregnancy for embryo/fetus characteristics and histopathological changes of the endometrium.Results.  Infected mice showed higher numbers of resorption and lower fetal weights than noninfected controls. These pathological phenomena were accompanied by macrophage activation, and increases both of CD4+ and CD8+ lymphocytes and of interferon‐γ and major histocompatibility complex class II expression at the endometrial level, as evaluated by immunohistochemistry.Discussion.  During pregnancy, preferential induction of Th2‐type cytokines downregulates Th1‐type responses, allowing fetal survival. Our results suggest that H. pylori infection can induce activation of resident uterine immune cells and/or recruitment of cells at the endometrial level. It can be hypothesized that the local Th1‐type response induced by H. pylori infection could alter the systemic Th1/Th2‐type cytokine balance at sites under particular physiopathological conditions of active tissue and/or vascular formation, such as pregnancy.Conclusions.  This is the first evidence in an animal model of the possible influence of H. pylori infection on pregnancy. Further work is required on its mechanism and its relevance for humans.
The Influence of Lactobacillus brevis on Ornithine Decarboxylase Activity and Polyamine Profiles in Helicobacter pylori‐Infected Gastric Mucosa
Authors: Linsalata Michele , Russo Francesco , Berloco Pasquale , Caruso Maria Lucia , Matteo Giovanni D.I. , Cifone Maria Grazia , Simone Claudio D.E. , Ierardi Enzo , Leo Alfredo Di 
Published: April 2004

ABSTRACTBackground.  Functional probiotics may prevent Helicobacter pylori infection, and some evidence suggests that they also possess antitumor properties. Lactobacillus brevis (CD2) is a functional Lactobacillus strain with peculiar biochemical features, essentially related to the activity of arginine deiminase. This enzyme catalyzes the catabolism of arginine and affects the biosynthesis of polyamines (putrescine, spermidine, and spermine). Polyamines are polycations found in high concentrations in both normal and neoplastic cells. Our aims were: 1, to assess whether oral administration of L. brevis (CD2) affects H. pylori survival in the human gastric mucosa; 2, to evaluate the effects of L. brevis (CD2) on polyamine biosynthesis in gastric biopsies from H. pylori‐positive patients.Materials and Methods.  For 3 weeks before endoscopy, 22 H. pylori‐positive dyspeptic patients randomly received (ratio 1 : 1) high oral doses of L. brevis (CD2) or placebo. Before and after treatment, H. pylori infection was determined by urea breath test (UBT). In gastric biopsies, ornithine decarboxylase activity and polyamine levels were, respectively, evaluated by a radiometric technique and high‐pressure liquid chromatography (HPLC).Results.  L. brevis (CD2) treatment did not eradicate H. pylori. However, a reduction in the UBT delta values occurred, suggesting a decrease in intragastric bacterial load. Significantly, L. brevis (CD2) induced a decrease in gastric ornithine decarboxylase activity and polyamine levels.Conclusions.  Our data support the hypothesis that L. brevis (CD2) treatment decreases H. pylori colonization, thus reducing polyamine biosynthesis. Alternatively, the arginine deiminase activity following L. brevis (CD2) administration might cause arginine deficiency, preventing polyamine generation from gastric cells.
Mechanism of Action of Low Recurrence of Gastritis Caused by Helicobacter pylori with the Type II Urease B Gene
Authors: Badruzzaman Md. , Matsui Hidetaka , Fazle Akbar Sk. Md. , Matsuura Bunzo , Onji Morikazu 
Published: April 2004

ABSTRACTBackground.  Low recurrence of gastritis is seen in patients infected with Helicobacter pylori carrying the type II urease B gene, compared with H. pylori carrying types I and III. The underlying mechanism has been studied in terms of the urease activity and interleukin (IL)‐8 production capacity of different strains of H. pylori.Materials and Methods.  Forty‐five patients infected with different strains of H. pylori (type I; 15, type II; 15 and type III; 15) were enrolled in the study. H. pylori was isolated from gastric mucosa and cultured in the presence of urea at pH 5.5 to evaluate urease activity. The capacity of different strains of H. pylori to induce IL‐8 mRNA and IL‐8 from a human gastric cancer cell line and human peripheral blood mononuclear cells was evaluated.Results.  The urease activity of type II H. pylori[523 ± 228 µg of ammonia/dl/108 colony‐forming units (CFU)/ml] was significantly lower than that of type I (1355 ± 1369 µg of ammonia/dl/108 CFU/ml) and type III (1442 ± 2229 µg of ammonia/dl/108 CFU/ml) (p < .05). Gastric cancer cells cocultured with type II H. pylori produced lower levels of IL‐8 mRNA compared with type I and type III H. pylori. The levels of IL‐8 were also significantly lower in cultures induced by type II H. pylori compared with those induced by type I and type III H. pylori. Peripheral blood mononuclear cells also produced lower levels of IL‐8 when cocultured with type II compared with type I H. pylori.Conclusions.  These results indicate that both the lower level of urease activity and the low IL‐8‐inducing capacity of type II H. pylori might underlie the lower recurrence rate of gastritis caused by type II H. pylori.
Physiological tolerance, climate change, and a northward range shift in the spittlebug, Philaenus spumarius
Authors: Karban Richard , Strauss Sharon Y. 
Published: April 2004

Abstract.  1. Considerable evidence indicates that the Earth's climate has warmed over the past 20 years and most models predict that this process will continue or accelerate. Previous studies involving butterflies and other species have shown that ranges have shifted towards the poles although the mechanisms responsible for these range shifts have not been demonstrated conclusively.2. Here it is reported that the range of the meadow spittlebug has moved northward along the California coast since 1988.3. Survival and reproduction of this species in previous laboratory experiments were very sensitive to humidity and temperature. Small deviations from optimal conditions resulted in high mortality.4. These laboratory results were corroborated by annual field censuses from one location since 1983 in which population densities of spittlebug nymphs were positively correlated with summer humidity and negatively correlated with temperature deviations from the published optimum. Thus it is shown that there are strong links between physiological tolerance and a geographic range shift associated with climatic change.
Queen lifespan and colony longevity in the antHarpegnathos saltator
Authors: Liebig Jürgen , Poethke Hans‐Joachim 
Published: April 2004

Abstract. 1. The longevity of field colonies was investigated in the ponerine antHarpegnathos saltator(Jerdon) in which either reproductive workers (gamergates) or a single queen reproduce.2. Data from 3 years were used to calculate the ratio between queen‐right (n = 50) and gamergate (n = 12) colonies that can be used to derive the colony mortality of gamergate colonies. Using the survival rates of queens in the laboratory, extrinsic and intrinsic mortality rates of queen‐right colonies were calculated.3. No significant differences in the sizes of queen‐right and gamergate colonies above 14 workers was found, suggesting that mortality of established colonies is not size related.4. The mortality of gamergate colonies is 4.17 times higher than the intrinsic mortality of queen‐right colonies.5. In the laboratory, mean survival time of queens in colonies of more than 14 workers was 1.79 years.6. Estimated mean survival time of queen‐right and gamergate colonies in the field varies between 0.78 and 0.43 years respectively, when no costs of conflict during the replacement of queens occur; however, when the latter costs increase colony mortality to a level similar to extrinsic mortality, the calculated longevity of queen‐right colonies would increase to 1.02 years.