Construction and immunological assessment of Salmonella typhimurium expressing fox sperm LDH-C4

This study examined immune responses of foxes to oral doses of recombinant Salmonella typhimurium expressing fox sperm-specific lactate dehydrogenase (fLDH). The cDNA for fLDH was cloned into the expression plasmid pKK233.2 (pKKfLDH). Salmonella typhimurium aroA- (SL3261) was transformed with either the pKK233.2 plasmid alone (SpKK) or the pKKfLDH construct (SpKfLDH). The fLDH expressed by SpKfLDH retained enzymatic activity and was recognized by human LDH-C4-specific antibody. Male European red foxes (Vulpes vulpes) were given an initial oral dose of 1 x 10(11) cfu of either SpKK (control, n = 3) or SpKfLDH (test, n = 6), followed four weeks later with a further dose of 1 x 10(11) cfu. Antibodies to Salmonella lipopolysaccharide (LPS-04) and fLDH were measured in plasma and saliva for eight consecutive weeks after the initial doses. Both LPS-04 IgG- and IgA-specific antibodies as well as fLDH-specific IgG antibodies were detected in plasma and saliva. However, there was a marked fLDH-specific IgA response in saliva consistent with induction of the common mucosal immune system. The antibody measurements demonstrated the feasibility of using recombinant Salmonella as an oral vaccine to elicit gamete antigen-specific mucosal immune responses in foxes.

The Wiskott-Aldrich syndrome gene as a candidate gene for atopic dermatitis

Atopic dermatitis is a multifactorial disorder probably caused by environmental factors in combination with susceptibility genes. The clinical similarity between atopic dermatitis and the eczema manifestation in patients with Wiskott-Aldrich syndrome made the previously identified WAS gene in chromosome sub-band Xpl 1.23 an interesting candidate gene for atopic dermatitis. We studied linkage and association to the WAS gene region using four polymorphic microsatellite markers in 406 Swedish families with at least two siblings affected with atopic dermatitis (in total 1514 individuals). In the analyses, we studied two qualitative traits: atopic dermatitis and elevated allergen-specific serum IgE antibodies, and one quantitative trait, a severity score of atopic dermatitis. We found that the marker MAOB gave positive linkage with a maximum lod score of 1.68 (p<0.05) to the severity score of atopic dermatitis. Association could not be seen to atopic dermatitis nor to elevated allergen-specific serum IgE antibodies in this region using the transmission disequilibrium test. Our results indicate that either the WAS gene or another gene in the area contributes to the severity of atopic dermatitis.

Site distribution in resin beads as determined by confocal Raman spectroscopy

Scanning confocal Raman spectroscopy was used to study the distribution of reactive sites within a resin bead used for solid-phase synthesis. The distribution of NH2 groups in aminomethylated polystyrene resin (APS) was determined by doping with varying amounts of 4-cyanobenzoic acid. The extent of loading was determined by both elemental analysis and ninhydrin assays. The spatial distribution of the coupled 4-cyanobenzamide within the bead was determined to an in-plane resolution of 1 microm and depth resolution of about 4 microm, using the strong Raman CN stretching vibrational transition at 2230 cm(-1). Dry and swollen beads were studied and the distribution was found to be essentially uniform throughout the bead in all cases.

Polarizability fields for use in three-dimensional quantitative structure-activity relationship (3D-QSAR)

Comparative molecular field analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) technique, has proven to be a valuable tool in the field of rational drug design. In its native form, CoMFA utilizes a pseudoreceptor, in the form of a regularly spaced lattice of probe atoms, to characterize the steric and electrostatic properties of a series of mutually superimposed molecules. Statistical analyses are performed in an attempt to correlate changes in these shape and charge related fields to observed differences in biological activities at a given target. Graphical analyses of the resulting "negative receptor images" have been demonstrated to provide insight into the physicochemical requirements of novel ligands. Several groups have previously demonstrated the benefits of additional or alternative fields for these types of analyses. In this report, a novel molecular potential field derived from atomistic contributions to molecular polarizability is presented. Comparison studies will be presented using literature data sets and CoMFA models derived from steric, electrostatic, and polarizability fields. The overall conclusion is that molecular polarizability fields derived from semiempirically determined atomic polarizabilities are highly predictive and graphically descriptive supplements to, and perhaps surrogates for, the standard CoMFA steric and electrostatic fields.

Birt-Hogg-Dubé syndrome: mapping of a novel hereditary neoplasia gene to chromosome 17p12-q11.2

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant neoplasia syndrome characterized mainly by benign skin tumors, and to a lesser extent, renal tumors and spontaneous pneumothorax. To map the BHD locus, we performed a genome-wide linkage analysis using polymorphic microsatellite markers on a large Swedish BHD family. Evidence of linkage was identified on chromosome 17p12-q11.2, with a maximum LOD score of 3.58 for marker D17S1852. Further haplotype analysis defined a approximately 35 cM candidate interval between the two flanking markers, D17S1791 and D17S798. This information will facilitate the identification of the BHD gene, leading to the understanding of its underlying molecular etiology.

Linkage and association to candidate regions in Swedish atopic dermatitis families

We have studied, in 406 families with at least two siblings affected with atopic dermatitis (in total 1514 individuals) from the Swedish population, linkage and association to five chromosomal regions (2q35, 5q31-33, 6p21, 11q13 and 14q11) previously implicated in atopic diseases. The region on 14q11 gave evidence for linkage to atopic dermatitis (NPL-score: 2.36, P<0.009). In the 11q13 region, there was a clear association to an intragenic marker in the beta-subunit of the high-affinity IgE receptor for raised allergen-specific serum IgE levels (P<0.009). When a quantitative variable for the severity of atopic dermatitis was studied, evidence was found in favour of linkage to the 5q31-33 region, with the highest Z-score (2.06) close to the marker D5S458 (P<0.005).

Election debrief

SO NEW LABOUR are back in with another landslide. Is that good or bad for nurses and other health care workers? The answer depends very much on two factors, the first of which is dependent on the second.

In-vitro visualization of biopsy needles with ultrasound: a comparative study of standard and echogenic needles using an ultrasound phantom

AIM

To demonstrate the circumstances where echogenically enhanced biopsy needles confer an increase in visualization during ultrasound-guided biopsy using an in-vitro experiment.

MATERIALS AND METHODS

An experiment using both standard and echogenically enhanced needles was conducted in a purpose built interventional phantom. The needle tip echogenicity and shaft visualization was recorded at different angles (20 and 60 degrees ) between the ultrasound probe and needle. The needle tip echogenicity was also recorded in four different angles of bevel rotation. The experiment was performed using a total of 18 different needles of 18 and 20 gauge.

RESULTS

The experiment confirmed some previous findings. The needle was better visualised at an angle of approximately 60 degrees to the probe. The needle tip was optimally visualized with the bevel facing the transducer or 180 degrees to it. Needle tip movement improved conspicuity. Using an optimal angle of approach (60 degrees ) the use of an echogenic needle did not confer any increase in conspicuity. If the transducer to needle angle was suboptimal (20 degrees ) then there was increased visualization of some echogenically enhanced needles.

CONCLUSION

Optimisation of the conditions prior to ultrasound-guided needle biopsy will increase the visualization of the chosen device thus aiding the interventionalist. Needle gauge, bevel position, movement of the needle and the probe to needle angle all affect conspicuity. Needle coating or roughening does not improve tip visualization if the angle between the needle and probe can be optimized (60 degrees ). In unfavourable situations when the angle is suboptimal (20 degrees ), we have shown that echogenic enhancement of the needle tip can make it more visible.

Physician perceptions of a national formulary

OBJECTIVE

To assess the perceptions of US Department of Veterans Affairs (VA) physicians regarding effects of a National Formulary (NF) on patient care, access to drugs, physician workload, and resident training approximately 1 year after it was implemented.

STUDY DESIGN

Cross-sectional survey.

METHODS

A questionnaire was sent to attending physicians working within the VA healthcare system. Participants included general internists (n = 2824), neurologists (n = 238), psychiatrists (n = 997), general surgeons (n = 429), and urologists (n = 152). The response rate was 45%.

RESULTS

Most physicians (63%) thought that they could prescribe needed drugs; 65% agreed that patients could obtain needed nonformulary drugs. One third disagreed that access to prescription pharmaceuticals had increased; 29% stated the NF impinged on providing quality care to their own patients, and 21% thought it did so to patients from other VA facilities. Thirty eight percent of physicians perceived the NF to be more restrictive than private sector formularies; 16% thought that the NF diminished the ability to train residents for managed care. Forty percent thought that the NF added to workload. Generalists more often perceived that the NF improved their ability to provide care compared with neurologists (27% vs 18%, P = .046), psychiatrists (27% vs 22%, P = .027), and internal medicine subspecialists (27% vs 18%, P = .001). Physicians with more clinic time were more likely to perceive that the NF increased workload.

CONCLUSION

Although differences of opinions among physicians were noted, most responding VA physicians did not perceive that the NF adversely affected patient care, access to pharmaceuticals, physician workload, or resident training.

Influence of resin cross-linking on solid-phase chemistry

A range of PS-DVB resins were prepared by suspension polymerization with styrene, p-chloromethyl styrene, and DVB. Yields of polymerization increased (from 40% to almost 80%) with increasing cross-linking. The beads exhibited the expected swelling characteristics, with the 0.3% resin swelling to almost 9 times its dry volume in CHCl3. Kinetics of cleavage of the dye Methyl Red from the range of Rink linked resins showed rate enhancements of up to 500% between the 6.0 and the 0.3% cross-linked resins. Total synthesis of Kawaguchipeptin B was carried out on the resins, and their performance during the syntheses was investigated. Contrary to expectations, the purities of the cyclic peptide product increased with increasing resin cross-linking doubling from the 0.3-6.0% resin. A Suzuki reaction showed the half-lives of reaction increased with increasing resin cross-linking with an 11-fold increase in half-life between the 0.3-2.7% resin. Surprisingly, we observed very little reaction in the case of the 3.0 and 6.0% cross-linked resins.

Parametric excitation of Alfven waves by gravitational radiation

We consider the parametric excitation of Alfven waves by gravitational radiation propagating on a Minkowski background, parallel to an external magnetic field. As a starting point, standard ideal magnetohydrodynamics equations incorporating the curvature of space-time has been derived. The growth rate of the Alfven waves has been calculated, using the normal-mode approach. Various astrophysical applications of our investigations are discussed, and finally we demonstrate that the coupling coefficients of the interacting modes fulfill the Manley-Rowe relations.

Optimising inhibitors of trypanothione reductase using solid-phase chemistry

A series of inhibitors of the enzyme trypanothione reductase has been identified using directed solid-phase chemistry. The compounds were based on a series of polyamine scaffolds and used the natural product kukoamine A as the lead structure. A compound with a Ki of 76 nM was identified, although somewhat surprisingly the compound appeared to be noncompetitive in nature.

Systematic review of water fluoridation

OBJECTIVE

To review the safety and efficacy of fluoridation of drinking water.

DESIGN

Search of 25 electronic databases and world wide web. Relevant journals hand searched; further information requested from authors. Inclusion criteria were a predefined hierarchy of evidence and objectives. Study validity was assessed with checklists. Two reviewers independently screened sources, extracted data, and assessed validity.

MAIN OUTCOME MEASURES

Decayed, missing, and filled primary/permanent teeth. Proportion of children without caries. Measure of effect was the difference in change in prevalence of caries from baseline to final examination in fluoridated compared with control areas. For potential adverse effects, all outcomes reported were used.

RESULTS

214 studies were included. The quality of studies was low to moderate. Water fluoridation was associated with an increased proportion of children without caries and a reduction in the number of teeth affected by caries. The range (median) of mean differences in the proportion of children without caries was -5.0% to 64% (14.6%). The range (median) of mean change in decayed, missing, and filled primary/permanent teeth was 0.5 to 4.4 (2.25) teeth. A dose-dependent increase in dental fluorosis was found. At a fluoride level of 1 ppm an estimated 12.5% (95% confidence interval 7.0% to 21.5%) of exposed people would have fluorosis that they would find aesthetically concerning.

CONCLUSIONS

The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis. There was no clear evidence of other potential adverse effects.

Using behavior modification to promote wound healing

Successfully caring for patients with wounds under PPS demands that current practice approaches must change. Instead of focusing on dressings and techniques alone, this article describes how first addressing patients' psychological readiness for change can move them quickly to self-care and enhance wound healing, which results in cost savings and better outcomes.

Polymer-based materials to be used as the active element in microsensors: a scanning force microscopy study

Polymer-based materials can be incorporated as the active sensing elements in chemiresistor devices. Most of these devices take advantage of the fact that certain polymers will swell when exposed to gaseous analytes. To measure this response, a conducting material such as carbon black is incorporated within the nonconducting polymer matrix. In response to analytes, polymer swelling results in a measurable change in the conductivity of the polymer/carbon composite material. Arrays of these sensors may be used in conjunction with pattern recognition techniques for purposes of analyte recognition and quantification. We have used the technique of scanning force microscopy (SFM) to investigate microstructural changes in carbon-polymer composites formed from the polymers poly (isobutylene) (PIB), poly (vinyl alcohol) (PVA), and poly (ethylene-vinyl acetate) (PEVA) when exposed to the analytes hexane, toluene, water, ethanol, and acetone. Using phase-contrast imaging (PI), changes in the carbon nanoparticle distribution on the surface of the polymer matrix are measured as the polymers are exposed to the analytes in vapor phase. In some but not all cases, the changes were reversible (at the scale of the SFM measurements) upon removal of the analyte vapor. In this paper, we also describe a new type of microsensor based on piezoresistive microcantilever technology. With these new devices, polymeric volume changes accompanying exposure to analyte vapor are measured directly by a piezoresistive microcantilever in direct contact with the polymer. These devices may offer a number of advantages over standard chemiresistor-based sensors.

Pit latrine effluent infiltration into groundwater: the Epworth case study

Water can be a vehicle for the transmission of communicable diseases. Technologies have been developed to protect groundwater from external surface contamination. However, there is growing concern about the likelihood of pit latrine effluent infiltrating into groundwater reservoirs for well water supply systems. Investigations on seasonal variations and extent of pit latrine effluent infiltration into soil and groundwater have been carried out in Zimbabwe. Preliminary results show that groundwater flows in the direction of surface runoff, and that there is no lateral soil pollution above the groundwater surface. Pit latrine contents leach downwards and down slopes for distances that vary per season and soil type. The results also demonstrate the contribution of refuse pits and water collection methods to groundwater pollution.