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Notes: When standard triple therapy fails to eradicate Helicobacter pylori, quadruple ‘rescue’ therapy is often used which, in Europe, generally comprises colloidal bismuth subcitrate (CBS) based triple therapy and a proton pump inhibitor. Since hypochlorhydria could greatly increase absorption of the toxic bismuth ion from CBS, we investigated the bismuth status of patients receiving anti-H. pylori quadruple therapy.〈section xml:id="abs1-3"〉〈title type="main"〉Materials and Methods.In a prospective open label study 34 patients with nonulcer dyspepsia or peptic ulcer disease, who had failed to eradicate H. pylori with standard triple therapy, were subsequently treated with CBS, omeprazole, amoxycillin and metronidazole (BOAM). A further 35 patients received triple therapy for the eradication of H. pylori: CBS, amoxycillin and metronidazole (BAM) (n = 18); placebo bismuth, amoxycillin and metronidazole (AM) (n = 9); or omeprazole, amoxycillin and metronidazole (OAM) (n = 8). Whole blood bismuth levels were determined before and within 24 hours of completing treatment. Analysis of bismuth was by inductively coupled plasma mass spectrometry, and concentrations were compared between groups and with the Hillemand ‘alarm level’ for blood bismuth (50–100 µg/l).〈section xml:id="abs1-4"〉〈title type="main"〉Results.BOAM gave higher blood bismuth levels than BAM (difference in means 13.1, CI 6.0–20.2, p 〈 .001); three (8.8%) patients taking BOAM had concentrations within the Hillemand alarm level at 54.2, 64.7 and 91.8 µg/l. OAM and AM did not alter baseline blood bismuth levels.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions.Caution should be observed in prescribing CBS with gastric acid suppression, and alternative bismuth preparations should be considered.

Notes: Phase diagrams of some globular proteins have a fluid–fluid transition as well as a fluid–crystal transition. Homogeneous nucleation of the crystal from the fluid phase near the critical point of the fluid–fluid transition is examined. As the fluid–fluid critical point is approached, the number of molecules in the critical nucleus, the nucleus at the top of the free energy barrier to nucleation, is found to diverge as the isothermal compressibility. This divergence is due to a layer of the fluid phase of width equal to the fluid's correlation length which surrounds the core of the nucleus; the number of molecules in a crystalline environment in the nucleus does not diverge. The free energy barrier to nucleation remains finite but its derivative with respect to the chemical potential is equal to minus the number of molecules in the critical nucleus, and so diverges. © 2001 American Institute of Physics.

Notes: Starting from a protein solution which is metastable with respect to the crystalline phase, the effect of adding semidilute nonadsorbing polymer is considered. It is found to increase the chemical potential of the protein by a few tenths of kT, which may be enough to lower the barrier to nucleation of the crystalline phase by enough to allow crystallization. It is also shown that assuming that the polymer induces a pairwise additive attraction leads to qualitatively incorrect results. © 2001 American Institute of Physics.

Notes: The spatial variations in the stable carbon isotope composition (δ13C) of air and leaves (total matter and soluble sugars) were quantified within the crown of a well-watered, 20-year-old walnut tree growing in a low-density orchard. The observed leaf carbon isotope discrimination (Δ) was compared with that computed by a three-dimensional model simulating the intracanopy distribution of irradiance, transpiration and photosynthesis (previously parameterized and tested for the same tree canopy) coupled to a biophysically based model of carbon isotope discrimination. The importance of discrimination associated with CO2 gradients encountered from the substomatal sites to the carboxylation sites was evaluated. We also assessed by simulation the effect of current irradiance on leaf gas exchange and the effect of long-term acclimation of photosynthetic capacity and stomatal and internal conductances to light regime on intracanopy gradients in Δ. The main conclusions of this study are: (i) leaf Δ can exhibit important variations (5 and 8‰ in total leaf material and soluble sugars, respectively) along light gradients within the foliage of an isolated tree; (ii) internal conductance must be taken into account to adequately predict leaf Δ, and (iii) the spatial variations in Δ and water-use efficiency resulted from the short-term response of leaf gas exchange to variations in local irradiance and, to a much lesser extent, from the long-term acclimation of leaf characteristics to the local light regime.

Notes: Aims. Two methods of dissemination (simple and intensive) were used to disseminate a smoking cessation programme to doctors and midwives working in antenatal clinics. This paper describes the differential uptake of the smoking cessation programme by doctors and midwives. It investigates whether the number of smoking cessation interventions used differ due to the type of dissemination. It also examines the frequency with which doctors and midwives provide smoking cessation interventions after dissemination. Design. Clinics were randomized to the method of dissemination (simple or intensive). Pre-post test design was used to examine the relationship between dissemination method and professional status at baseline and follow-up. A baseline survey collected data on the use of smoking cessation intervention in the clinics prior to dissemination. A follow-up survey was conducted 18 months after the dissemination. Setting. Twenty-three public hospital antenatal clinics in NSW. Participants. All clinical staff (midwives and doctors) working in the clinic during the 1-2-week survey period prior to dissemination and 18 months after the dissemination were asked to participate. The response rate was 63% (223) at baseline and 64% (182) at follow-up. Only 48% of midwives and doctors at follow-up were working in the original clinic. Measures. The proportion of clinicians who initially adopted the programme; the proportion of clinicians who had used one or more programme components in the last week); the number of types of smoking cessation intervention provided (maximum = 13), and the estimated proportion of clients offered smoking cessation intervention. Findings. More midwives than doctors 'ever used' the programme (76% vs. 25%) and continued to implement (58% vs. 22%) the programme 18 months after dissemination. Both midwives and doctors increased the number of types of smoking cessation intervention offered at follow-up compared to baseline (mean difference 2.8). Midwives provided more smoking cessation interventions than doctors at baseline (mean difference 0.9) and at follow-up (1.6), regardless of method used to disseminate the programme. Midwives' mean estimates of the proportion of clients offered interventions were greater than doctors' (midwives' 59% vs. doctors' 35%) at follow-up. Conclusion. The dissemination of a smoking cessation programme increased the level of smoking cessation interventions used by doctors and midwives. Doctors and midwives differ in their uptake of smoking cessation programmes. This information can be used to plan programme dissemination strategies in the future.

Notes: 
 Aims. To test the feasibility of conducting a definitive randomized controlled trial of dexamphetamine substitution for amphetamine dependent people and provide preliminary data. 
Design. An open, two-group pre-post randomized controlled trial. 
Participants. Forty-one long-term, dependent amphetamine users seeking treatment. 
Intervention. Twenty subjects were offered weekly counselling. Twenty-one subjects were, in addition, prescribed up to 60 mg dexamphetamine daily. 
Measurements. Immunoassay and mass spectrometric urinalysis techniques were used to identify the presence of amphetamine and methylamphetamine in urine. The Opiate Treatment Index and Severity of Dependence Scale were used to collect pre- and post-self-report data. Subjects were screened using the Composite International Diagnostic Interview. 
Findings. Reduced street amphetamine use and amphetamine dependence was observed both in subjects prescribed dexamphetamine and subjects receiving counselling only. Treatment subjects appeared more likely to attend counselling. 
Conclusions. A definitive randomized controlled trial of dexamphetamine substitution using the techniques and instruments piloted in this study is feasible. Users appeared to be attracted and retained in substitution treatment. The intervention also appeared to be acceptable to clinicians.

Notes: Open reading frames (ORFs) are frequently inserted into group I self-splicing introns. These ORFs encode either maturases that are required for splicing of the intron or DNA endonucleases that promote intron mobility. A self-splicing intron in the tRNAfMet gene of Synechocystis PCC 6803, which has been proposed to have moved laterally within the cyanobacteria, contains an ORF that is unrelated to known intron-encoded endonucleases or maturases. Here, using an in vitro transcription–translation system, we show that this intronic ORF encodes a double-strand DNA endonuclease, I-Ssp6803I. I-Ssp6803I cleaves each strand of the intronless tRNAfMet gene adjacent to the anticodon triplet leaving 3 bp 3′ extensions and has no activity at intron–exon boundaries. Using an in vitro cleavage assay and scanning deletion mutants of the intronless target site, the minimal recognition site was determined to be a partially palindromic 20 bp region encompassing the entire anticodon stem and loop of the tRNAfMet gene. I-Ssp6803I represents a novel intron-encoded DNA endonuclease and is the first example of a chromosomally encoded group I intron endonuclease in bacteria.

Notes: Campylobacter jejuni strain 81-176 (HS36, 23) synthesizes two distinct glycan structures, as visualized by immunoblotting of proteinase K-digested whole-cell preparations. A site-specific insertional mutant in the kpsM gene results in loss of expression of a high-molecular-weight (HMW) glycan (apparent Mr 26 kDa to 〉 85 kDa) and increased resolution of a second ladder-like glycan (apparent Mr 26–50 kDa). The kpsM mutant of 81-176 is no longer typeable in either HS23 or HS36 antisera, indicating that the HMW glycan structure is the serodeterminant of HS23 and HS36. Both the kpsM-dependent HMW glycan and the kpsM-independent ladder-like structure appear to be capsular in nature, as both are attached to phospholipid rather than lipid A. Additionally, the 81-176 kpsM gene can complement a deletion in Escherichia coli kpsM, allowing the expression of an α2,8 polysialic acid capsule in E. coli. Loss of the HMW glycan in 81-176 kpsM also increases the surface hydrophobicity and serum sensitivity of the bacterium. The kpsM mutant is also significantly reduced in invasion of INT407 cells and reduced in virulence in a ferret diarrhoeal disease model. The expression of the kpsM-dependent capsule undergoes phase variation at a high frequency.

Notes: The Staphylococcus aureus gene for toxic shock toxin (tst) is carried by a 15 kb mobile pathogenicity island, SaPI1, that has an intimate relationship with temperate staphylococcal phage 80α. During phage growth, SaPI1 is excised from its unique chromosomal site, attC, replicates autonomously, interferes with phage growth, and is efficiently encapsidated into special small phage heads commensurate with its size. Upon transfer to a recipient organism, SaPI1 integrates at attC by means of a self-coded integrase. One or more phage functions are required for excision, autonomous replication and encapsidation of the element and, thus, the overall relationship between SaPI1 and 80α is similar to that between coliphages P4 and P2. Among other staphylococcal phages tested, only φ13 interacts with SaPI1, inducing excision but not replication or transfer of the element.

Notes: A study of all faculty in the Louisiana State University College of Agriculture was undertaken in Fall 1999 to better understand their perceptions and use of technology in the classroom environment resulting in a 55 percent response rate. The study was a follow-up to a 1998 study of students enrolled in all classes in the College. Like students, faculty were surveyed to discern awareness, expectations, and capabilities in using technology in the classroom. Faculty results and faculty/student comparisons were analyzed using frequency tabulations and paired t-tests. The study was designed to collect baseline information that could be used for planning and funding allocations for equipment and development activities for faculty in the context of increasing technology capabilities and teaching effectiveness. Results indicated that faculty, like students, are generally computer literate with almost all owning a personal computer; strongly prefer a combination of traditional and computer-supported teaching methods; and believe that computer-based technology in the classroom is very important to students' future competitiveness in the job market. However, faculty's perceptions of their proficiency in using technologies were significantly higher than the students' perceptions of these skills.