bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of ventilation/perfusion scintigraphy and helical CT for diagnosis of pulmonary embolism; strategy using clinical data and ancillary findings
Authors: Bajc Marika , Albrechtsson Ulf , Olsson Carl‐Gustav , Olsson Berit , Jonson Björn 
Published: March 2003

SummaryStudy objective: To address the question whether ventilation/perfusion scintigraphy (SCINT) or helical computed tomography (CT) should be the first hand method for diagnosis of pulmonary embolism (PE).Setting: Departments of radiology, nuclear medicine and internal medicine of a large university hospital.Patients: During 3 years all 128 patients examined for PE with both methods were analysed. The strategy of interpretation behind original clinical reports, i.e. clinical CT and clinical SCINT, was based upon basic criteria for PE, ancillary findings and information from the referring doctor and from previous examinations. Reviewed SCINT and CT reports were obtained from experts in each field blinded to clinical and laboratory data. The findings with respect to PE were classified as no PE, PE or non‐diagnostic. Other pathology than PE was described. A final diagnosis serving as reference was based upon CT, SCINT and other information including clinical follow for 6–24 months.Methods: Planar SCINT was made with ventilation always preceding perfusion. CT was made with contrast injection using 3 mm collimation and table feed of 3 mm s−1.Results: PE was diagnosed in 32 patients. For clinical and reviewed SCINT sensitivity was 91 and 97%, specificity 96 and 100% and rate of non‐diagnostic findings 10 and 9%, respectively. For clinical and reviewed CT sensitivity was 81 and 78%, specificity 99 and 100% and non‐diagnostic findings was observed in 8 and 1%, respectively. In patients with PE, concordant positive results were obtained with both modalities in 23 of 32 patients (72%).Conclusion: SCINT remains the first hand method because its high sensitivity, general feasibility, low radiation burden and low rate of non‐diagnostic findings in our setting. CT is indispensable when SCINT is not available or its result non‐diagnostic.
On‐ and off‐responses of heart rate to exercise – relations to heart rate variability
Authors: Javorka Michal , Žila Ivan , Balhárek Tomáš , Javorka Kamil 
Published: March 2003

SummaryDuring physical exercise, heart rate (HR) increases by parasympathetic withdrawal and increase of sympathetic activity to the heart. HR variability (HRV) in time and frequency domains provides information about autonomic control of the cardiovascular system. Non‐linear analysis using the Poincaré plot method is able to reveal supplementary information about cardiac autonomic control. The aim of this study was to determine the association between HRV parameters, the initial increase of HR at the onset of exercise (on‐response) and HR decrease in the recovery phase after acute exercise (off‐response). HR was continuously monitored in 17 healthy male subjects (mean age: 20·3 ± 0·2 (SEM) years) at rest (25 min supine; 5 min standing), during exercise (8 min of step test at 70% of maximal power output) and in the recovery phase (30 min supine). HRV analysis in time and frequency domains and evaluation of the Poincaré plot measures (length, widths) were performed on selected segments of HR time series. HR on‐ and off‐responses were quantified using an exponential curve fitting technique. The time constants Ton and Toff, representing the rate of on‐ and off‐responses to exercise, were computed. Postexercise HRV indices and time constant of on‐response – Ton – to exercise were negatively correlated. From preexercise HRV indices, only Poincaré plot parameters were correlated with Ton. No correlation between HRV indices and parameters of off‐response was found. In conclusion, preexercise HRV parameters are not closely correlated with the rate of cardioacceleration at the onset of exercise and cannot predict the rate of HR recovery. On the other hand, postexercise HRV parameters are related to the rate of initial adjustment of HR to exercise referring to the importance of rapid HR on‐response for a faster recovery after exercise.
Preserved bronchial dilatation after salbutamol does not guarantee protection against bronchial hyperresponsiveness
Authors: Sjöswärd Kerstin Naidu , Josefsson Martin , Ahlner Johan , Schmekel Birgitta 
Published: March 2003

SummaryRacemic salbutamol, a β2‐adrenoceptor agonist used for dilatation of airways, has recently been shown to induce lessened relaxation of bronchial smooth muscle and partial loss of bronchoprotection, seen as increased hyperresponsiveness, after regular treatment. The racemate undergoes stereo‐selective disposition, giving higher plasma levels of S‐salbutamol than that of bronchodilating R‐salbutamol, thus raising S : R ratios after repeated administration. Our aim was to evaluate whether increased bronchial hyperresponsiveness (BHR) could be found even after 1 day of repeated salbutamol inhalations, with β2‐receptor‐induced bronchial smooth muscle relaxation remaining and whether this would be associated with plasma levels of either enantiomer. Fifteen patients with stable asthma, aged 19–54 years, were included in a randomized, cross‐over study. An indirect bronchial challenge method was used [voluntary isocapnic hyperventilation of cold air (IHCA)], and airway condition tested by means of impulse oscillometry. Racemic salbutamol was inhaled three times during a 6‐h period. IHCA was performed and plasma concentrations of enantiomers were measured 4 h after the last dose. Tests were also performed without preceding drug treatment. β2‐Agonist‐produced bronchial dilatation and protection persisted in the majority of the 15 patients 4 h after repeated inhalations of salbutamol during 1 day. In only two of the 15 patients we could trace increased BHR after salbutamol. Neither dilatation nor protection could be linked to plasma levels of either R‐ or S‐salbutamol. The underlying mechanisms of BHR remain unknown and are dissociated from β2‐receptor‐mediated dilatation.
The Evolution of the U.S. National Wildlife Refuge System and the Doctrine of Compatibility
Authors: Curtin Charles G. 
Published: March 2003

This paper reviews the history and evolution of the United States National Wildlife Refuge System, perhaps the largest and oldest wildlife conservation system in the world. The refuge system is guided by the doctrine of compatibility, which permits only those uses on a refuge which are “compatible with the purposes for which the refuge was established.” Memoranda and documents spanning the last 100 years were examined, and key refuge personnel interviewed, to understand the historical basis for current refuge policies. Topics of particular importance were the origins of the compatibility doctrine, the origin and meaning of the sanctuary concept, and the means by which refuges were established.Through time, the refuge system has shifted from a policy of strict protection of wildlife to a policy of integrating public uses of refuges. The doctrine of compatibility has evolved to facilitate public use of wildlife refuges. Increasingly, the needs for recreation and resource use have interfered with the purposes far which refuges were established. A legislative solution may be needed to ensure that these areas are protected and remain viable reserves for wildlife and natural communities.The sustained conservation of reserve areas often represents a delicate balance between political constraints and biological realities. The examination of the National Wildlife Refuge System not only has ramifications for North American conservation, but illustrates many of the problems and pitfalls facing conservation and land management worldwide.
The Impact of Brown‐Headed Cowbird Parasitism on Populations of the White‐Crowned Sparrow
Authors: Trail Pepper W. , Baptista Luis F. 
Published: March 2003

Brown‐headed Cowbirds, Molothrus ater, are brood parasites on many species of North American Passerines. Cowbird parasitism is frequently cited as a contributing factor in the decline of United States passerine populations, based on three lines of evidence. First, range expansion and population increases by Cowbirds in this century are dramatic and well documented. Second, increasing rates of parasitism have been discovered in a variety of host species populations. Finally, direct negative effects of parasitism on certain vulnerable species notably Kirtland’s Warbler, Dendroica kirtlandii, have been demonstrated. It remains unproven, however, that Cowbirds have significant negative effects on more abundant and widely‐distributed hosts.We report here on the impact of Cowbird parasitism on populations of Nuttall’s White‐crowned Sparrow, Zonotrichia leucophrys nuttalli, in the San Francisco Bay Area. This widespread songbird is now subject to a 40–50% rate of parasitism in San Francisco, an increase from 5% only 15 years ago. Using known mortality and fecundity values, we calculate that this population of White‐crowns cannot maintain its numbers when the parasitism rate exceeds approximately 20%. Present levels of parasitism thus appear to threaten the longevity survival of this adaptable Songbird in the San Francisco Bay Area.
Willingness To Pay: A Method For Measuring Preferences For Maternity Care?
Authors: Donaldson Cam , Hundley Vanora , Mapp Tracy 
Published: March 2003

Background:The aim of this study was to assess the feasibility of the use of “willingness to pay” as a measure of the benefits of intrapartum care.Methods:A questionnaire was mailed to 150 pregnant women booking at Aberdeen Maternity Hospital in the northeast of Scotland, giving information on options for intrapartum care compiled from a recent randomized trial of care in a midwife‐managed delivery unit versus care in a consultant‐led labor word. Women were asked which type of care they preferred and what would be their maximum willingness to pay for their preferred option. Data were also collected on demographic and clinical characteristics.Results:Most women (55%) expressed a preference for care in a midwives unit. However, strength of preference, as reflected in willingness to pay, was greater among those in the smaller group, who expressed a preference for care in a consultant‐led labor ward. The willingness‐to‐pay results were not associated with ability to pay.Conclusions:These data should be used together with cost data to decide on provision of care. Given the strength of preference of the minority group, and if the cost implications are not too great, a flexible service that takes account of women's wishes should be provided, even if this goes against the trend for care of those at low risk. By analyzing choice of care by income groups and social class groupings, it is possible to examine whether willingness‐to‐pay results are associated with indicators of ability to pay. In this case, they were not. Willingness to pay has an advantage in allowing respondents to account for more than just health gain when valuing different types of care. (BIRTH 25:1, March 1998)
Concepts and Controversies in the Management of Group B Streptococcus During Pregnancy
Authors: Glantz J. Christopher , Kedley Karen E. 
Published: March 2003

Background:Group B beta‐hemolytic streptococcus colonizes 20 percent of pregnant women. Intrapartum fetal colonization leads to invasive disease in 1 to 2 infants of every 1000 births in the United States, and has a mortality of approximately 6 percent. Several protocols using intrapartum chemoprophylaxis have been devised to improve management of the disease, but confusion continues about details and implementation. This review examined the clinical issues, current management protocols, and advantages and disadvantages of these protocols for group B streptococcus.Methods:We reviewed the literature and described the epidemiology, detection methods, risk factors, neonatal disease potential of group B streptococcus, and the historical development of management protocols. Two current alternatives, the American College of Obstetricians and Gynecologists' risk‐based protocol and the Centers for Disease Control and Prevention's screening‐based protocol, are described and compared.Results:The risk‐based protocol does not entail antepartum screening, but treats women with certain risk factors during labor. The screening‐based protocol includes cultures at 35 to 37 weeks' gestation, and offers intrapartum prophylaxis to all women with positive cultures. Uncultured women with risk factors are treated. Both protocols involve high rates of intrapartum antibiotic use and both may significantly lower rates of neonatal group B streptococcus sepsis (screening‐based more than risk‐based for both). The risk‐based approach is simpler than the screening‐based approach.Conclusions:Practitioners should select one of the two protocols and use it consistently. The differences in efficacy are small; a practitioner may not see a difference in outcomes over the course of his or her career, although more antibiotics will be administered using the screening‐based approach. (BIRTH 25:1, March, 1998)
An Alternative Non‐Macrolide, Non‐Imidazole Treatment Regimen for Curing Helicobacter pylori and Duodenal Ulcers: Ranitidine Bismuth Citrate Plus Amoxicillin
Authors: Graham David Y. , Breiter Jeffrey R. , Ciociola Arthur A. , Sykes Deborah L. , McSorley David J. , The Rbc Pylori H. , Group Study 
Published: March 2003

Background. Because patients who fail to be cured of H. pylori infection following macrolide or imidazole therapy are difficult to treat, there is a clear need for a reasonably effective and simple second‐line treatment regimen. The purpose of these two studies was to evaluate the efficacy of ranitidine bismuth citrate (RBC) plus amoxicillin for the cure of H. pylori infection and for healing duodenal ulcers and preventing ulcer relapse. Materials and Methods. Two identically designed randomized, double‐blind, double‐dummy studies were conducted in patients with an H. pylori‐associated duodenal ulcer. Patients were treated with either RBC 400 mg bid for 4 weeks plus amoxicillin 500 mg qid for 2 weeks, RBC 400 mg bid for 4 weeks and placebo qid for 2 weeks, placebo bid for 4 weeks and amoxicillin 500 mg qid for 2 weeks, or placebo bid for 4 weeks and placebo qid for 2 weeks. Patients with healed ulcers after 4 weeks of treatment were eligible for entry into a 24‐week observation phase for the assessment of H. pylori status (culture, histology, and CLOtestTM) and ulcer relapse. Results. A total of 229 patients with confirmed H. pylori infection at baseline were evaluated. Of these, 132 whose ulcers had healed entered the 24‐week posttreatment observation phase. The combination of RBC plus amoxicillin resulted in higher H. pylori cure rates (55%) and higher duodenal ulcer healing (74%) than did either treatment alone. All treatments were well tolerated. Conclusions. The combination of ranitidine bismuth citrate plus amoxicillin cures H. pylori infection in more than half of the patients treated. This treatment regimen shows promise as the basis for future non‐macrolide, non‐imidazole triple therapy regimens for curing H. pylori infection. Such regimens may be appropriate second‐line treatment for patients who are resistant to or who are unable to tolerate macrolide‐ or imidazole‐containing therapies.
How Do Practicing Clinicians Manage Helicobacter pylori‐Related Gastrointestinal Diseases in Germany? A Survey of Gastroenterologists and Family Practitioners
Authors: Breuer Thomas , Sudhop Thomas , Goodman Karen J. , Graham David Y. , Malfertheiner Peter 
Published: March 2003

Background.Since the bacterium H. pylori was identified in 1982, overwhelming evidence has implicated it as the causal factor in the occurrence and relapse of peptic ulcer disease. The major objective of this study was to examine the extent to which physicians recognize H. pylori as a causal agent in peptic ulcer disease or as potential cofactor in other gastrointestinal diseases, and the extent to which this knowledge has influenced diagnostic and therapeutic practices.Materials and Methods.Using a national mail survey in Germany in September 1995, 1197 family practitioners and 1197 gastroenterologists were selected for the study.Results.Of the surveyed physicians, 756 (32%) responded. Family practitioners treated almost 50% of their patients with initial presentation of suspected ulcer disease without ordering further diagnostic tests. More than 25% of the family practitioners and 14% of the gastroenterologists reported that they do not treat diagnosed H. pylori infection in the first presentation of duodenal ulcer. At the time we conducted the study, 22% of responding family practitioners and 5% of responding gastroenterologists treated the first presentation of H. pylori‐positive ulcer disease with regimens determined to be ineffective according to the available literature.Conclusions.Gastroenterologists preferred to treat H. pylori infection when the associated disease was one for which a causal relationship had been more clearly established, while family practitioners showed less discrimination. In order to provide optimal therapy aimed at minimizing the course and consequences of H. pylori‐related diseases, researchers in the field must ensure continuous dissemination of current knowledge.
An Investigation of the Molecular Basis of the Spontaneous Occurrence of a Catalase‐Negative Phenotype in Helicobacter pylori
Authors: Manos Jim , Kolesnikow Tassia , Hazell Stuart L. 
Published: March 2003

Background.The discovery of a highly active catalase in Helicobacter pylori that in some strains may lose its activity has generated strong scientific interest. We have characterized a spontaneous catalase‐negative isolate of H. pylori (UNSW‐RU1) and sequenced katA in the parent strain and the promoters of both phenotypes as a prelude to understanding the genetic processes leading to the failure to express catalase.Materials and Methods.Protein extracts from both phenotypes were examined for catalase on 2D‐PAGE and analyzed by Western blot‐based immuno‐analysis. Presence of catalase mRNA was detected by Northern blot. Hi‐Fidelity PCR was used to sequence the katA promoter while katA was sequenced using cycle‐sequencing. The transcription start site was located by primer extension.Results.Catalase protein was absent in UNSW‐RU1 (KatA−) by 2D‐PAGE and Western blot, as was catalase mRNA by Northern blot, indicating that the cause of the KatA− phenotype was at the level of transcription. No mutations were found in the promoter region of the KatA− isolate. The transcription start site was identified 55 bp upstream of the ATG site and putative RNA polymerase binding sites were mapped at “−10” and “−35”. A Fur box was identified 181 bp upstream of the transcription start site. The sequences of an 876 bp ORF and a 366 bp Escherichia coli phnA homologue were identified.Conclusions.The UNSW‐RU1 (KatA−) phenotype does not express KatA or transcribe katA. The absence of defects in its promoter and a large part of its ORF indicates that loss of activity may be due to a mutation in an accessory gene essential for catalase expression, or to the binding of a repressor preventing katA transcription.
Highly Sensitive Urine‐Based Enzyme‐Linked Immunosorbent Assay for Detection of Antibody to Helicobacter pylori
Authors: Katsuragi Kiyonori , Noda Atsunari , Tachikawa Tetsuya , Azuma Atsushi , Mukai Fumie , Murakami Kazunari , Fujioka Toshio , Kato Mototsugu , Asaka Masahiro 
Published: March 2003

Background.Enzyme‐linked immunosorbent assay (ELISA) has been widely used for detection of Helicobacter pylori (H. pylori), but sample collection is often invasive, complicated, and expensive. Urine samples can be obtained noninvasively and are easier and safer to handle than serum samples. A urine‐based ELISA, if found to be accurate, would therefore be a useful alternative to serum‐based tests for H. pylori.Methods.An ELISA method was developed for detection of antibodies to H. pylori in urine. Its sensitivity and specificity were compared with those of three commercially available serum‐based ELISA kits and the 13C urea breath test (13C‐UBT) using samples from 99 healthy volunteers and 20 patients with gastric disorders.Results.With the assumption that 13C‐UBT results are 100% accurate, the sensitivity and specificity of the urinary ELISA were 99% and 100%, respectively, and the accuracy (99%) was superior to those of the three serum ELISAs tested. Immunostaining profiles on Western blot analysis using serum samples were almost identical to those obtained using paired urine samples.Conclusions.These findings suggest that the differences observed among ELISA test results may be due principally to differences between the profiles of antigen coated on plates for the assays, rather than to differences between antibodies in serum and urine. The urine‐based ELISA (URINELISA H. pylori) developed in this study is very accurate and would be useful for screening H. pylori infection as an alternative to serum ELISAs.
Practice Patterns for Peptic Ulcer Disease: Are Family Physicians Testing for H. pylori?
Authors: Zoorob Roger J. , Jones Glenn N. , Mainous Arch G. , Hagen Michael D. 
Published: March 2003

Background. Peptic ulcer disease (PUD) is a problem common in family medicine. Recent evidence of Helicobacter pylori as an etiological agent of PUD has led to National Institutes of Health recommendations for treatment to eradicate H. pylori through antibiotic therapy. The purpose of this study is to examine practice patterns of family physicians in treating PUD, their use of H. pylori testing, and knowledge of current recommendations for PUD.Materials and Methods. A mail survey was sent to a random sample of 1,500 members of the American Academy of Family Physicians. Six hundred thirty useable surveys (49.1%) were available for analysis. Descriptive statistics were obtained, as were inferential statistics focusing on the relationship of physician background characteristics to practices.Results. Thirty‐eight percent of the respondents order diagnostic procedures for the majority (50% or more) of their suspected PUD cases. Of the physicians who reported ordering any diagnostic tests, 52% ordered the combination of upper gastrointestinal series and endoscopic gastroduodenoscopy. For patients with clinical diagnoses of PUD, 77% of doctors reported ordering a diagnostic test for H. pylori. Approximately 68% were aware that some kind of guidelines existed; only 11% reported that they were familiar with the National Institutes of Health recommendations for PUD.Conclusions. Although some of the practices of family physicians for treatment of PUD deviate from current recommendations, the majority of practices are consistent with current evidence.
In Search of the Holy Grail of Heliocobacter pylori Remedies
Authors: Hopkins Robert J. 
Published: March 2003

AbstractIn this issue, Gisbert et al. (pp. 157–62) present the results of a noncomparative study evaluating a twice daily, 5‐day regimen of ranitidine bismuth citrate, amoxicillin, clarithromycin and metronidazole twice daily for Helicobacter pylori cure. This study is one of a few stuides that evaluate a 5‐day triple antimicrobial regimen in combination with a antisecretory agent. Although the study design precludes making any definite conclusion, it does encourage additional investigation of these types of regimens. Randomized controlled trials (RCTs) using regimens containing multiple agents should consider both standard‐of‐care comparator regimens and comparator regimens that will provide a better understanding of why regimens are more effective or better tolerated. The goal of treatment should be to maintain a lower bound 95% confidence interval (CI) of the point estimate of greater than 80% and a ‘delta’ (lower bound 95% CI of the difference in rates) of less than 10%. All RCTs should conduct susceptibility testing to evaluate the impact of resistance on efficacy and explain eradication failures. Finally, consideration should be given to the inclusion of patients with functional dyspepsia in H. pylori studies evaluating H. pylori cure since patients with peptic ulcer disease are becoming harder to find.