Benzalkonium chloride. A potential disinfecting irrigation solution for orthopaedic wounds

The efficacy of benzalkonium chloride was evaluated as an irrigating solution for the eradication of Staphylococcus aureus from a contaminated orthopaedic wound. Thirty Sprague Dawley rats were randomized into two groups. A stainless steel wire was placed in a lumbar spinous process, and the wound was inoculated with 10(7) or 10(6) colony forming units of Staphylococcus aureus. The wound was irrigated with 1 L of normal saline or 0.1% benzalkonium chloride solution. The animals were sacrificed, and cultures were obtained. Rats inoculated with 10(7) colony forming units of Staphylococcus aureus and irrigated with benzalkonium chloride had a significant decrease in the total number of positive cultures, deep wound cultures, and stainless steel wire cultures. Rats inoculated with 10(6) colony forming units of Staphylococcus aureus and irrigated with benzalkonium chloride also had a significant decrease in the total number of positive cultures, deep wound cultures, and stainless steel wire cultures. In a parallel noninoculation study, histologic evaluation of tissues did not show toxicity in the rats irrigated with benzalkonium chloride. This study shows that benzalkonium chloride is more effective than normal saline as an irrigating agent for eradicating Staphylococcus aureus from a contaminated orthopaedic wound.     

Tissue distribution of erythropoietin and erythropoietin receptor in the developing human fetus

The purpose of this exploratory study was to describe a group of African American women who smoke crack. Using aggregate data from 208 interviews with women crack smokers, we randomly selected 25 women's interview data to create the 25 life-lines. These life-lines were developed in a similar manner to the time-line analysis described by Fullilove and her colleagues (1992); we focused on events that are either extraordinarily disturbing (e.g., rape, incest, death of a child, etc.), events that are usual but often stressful (e.g., birth of a child, death of a parent, etc.), and on periods of drug use. We chose this method of analysis so as to highlight the context in which many women come to use crack cocaine. The life-lines provided a retrospective (but time-ordered) perspective and in several ways provided preliminary support for a stress-diathesis perspective.     

Statistical methods in computational anatomy

This paper reviews recent developments by the Washington/Brown groups for the study of anatomical shape in the emerging new discipline of computational anatomy. Parametric representations of anatomical variation for computational anatomy are reviewed, restricted to the assumption of small deformations. The generation of covariance operators for probabilistic measures of anatomical variation on coordinatized submanifolds is formulated as an empirical procedure. Populations of brains are mapped to common coordinate systems, from which template coordinate systems are constructed which are closest to the population of anatomies in a minimum distance sense. Variation of several one-, two- and three-dimensional manifolds, i.e. sulci, surfaces and brain volumes are examined via Gaussian measures with mean and covariances estimated directly from maps of templates to targets. Methods are presented for estimating the covariances of vector fields from a family of empirically generated maps, posed as generalized spectrum estimation indexed over the submanifolds. Covariance estimation is made parametric, analogous to autoregressive modelling, by introducing small deformation linear operators for constraining the spectrum of the fields.     

Selecting users for participation in IT projects: Trading a representative sample for advocates and champions?

The selection of users for participation in IT projects involves trade-offs between multiple criteria, one of which is selecting a representative cross-section of users. This criterion is basic because trading it for other criteria means basing designs on information biased toward some user groups at the expense of others. Based on interviews in development and customer organizations we find that their criteria for user selection favor persons who can contribute to the progress of the IT project over persons who are representative of the full range of users. A highly valued contribution from participating users is the ability to advocate a vision for the system and champion its organizational implementation. A survey in one customer organization shows that respondents’ personal traits explain up to 31% of the variation in their experience of aspects of the usability of a recently introduced system. Thus, unless participating users are representative as to these personal traits, IT projects may, inadvertently, bring about systems that will fail to satisfy many users.     

Effect of heat input and preheating on hydrogen assisted weld joint cracking of a 0.13% C, 1.5% Mn, 0.032% Nb high strength steel of 50 mm plate thickness in the IRC test

The effects of preheating and heat input on hydrogen assisted weld joint cracking are investigated at a restraint intensity of 32 kN mm^?2 of a 0.13% C, 1.5% Mn, 0.032% Nb high strength steel of 50 mm thickness in the IRC test, using a high hydrogen experimental electrode of 530 N mm^?2 yield strength. For a heat input ranging from 0.6 to 1.05 kJ mm^?1 a critical preheating temperature of 140°C for almost complete crack prevention, for a range from 1.5 to 2.05 kJ mm^?1, 120°C were found respectively. Nominal stresses at the ends of the 70-80 mm long welds at the start of extensive cracking increase with heat input and preheat, the crack propagating from the HAZ into the weld metal quickly. Under conditions without or close to cracking, however, final stresses after 18 h are reduced with heat inputs. Consequently, crack critical combinations of preheating and heat input are linked to stresses decreasing with heat input but increasing with preheat. From the established IRC-test diagram required combinations of local preheat and heat input for either avoiding hydrogen cracking or overstressing of the weld metal can be determined. Currently used cracking prediction procedures do not consider the effect of heat input and preheat on stress sufficiently and, therefore, may provide unsafe conclusions.     

The NS1 polypeptide of the murine parvovirus minute virus of mice binds to DNA sequences containing the motif [ACCA]2-3

A DNA fragment containing the minute virus of mice 3' replication origin was specifically coprecipitated in immune complexes containing the virally coded NS1, but not the NS2, polypeptide. Antibodies directed against the amino- or carboxy-terminal regions of NS1 precipitated the NS1-origin complexes, but antibodies directed against NS1 amino acids 284 to 459 blocked complex formation. Using affinity-purified histidine-tagged NS1 preparations, we have shown that the specific protein-DNA interaction is of moderate affinity, being stable in 0.1 M salt but rapidly lost at higher salt concentrations. In contrast, generalized (or nonspecific) DNA binding by NS1 could be demonstrated only in low salt. Addition of ATP or gamma S-ATP enhanced specific DNA binding by wild-type NS1 severalfold, but binding was lost under conditions which favored ATP hydrolysis. NS1 molecules with mutations in a critical lysine residue (amino acid 405) in the consensus ATP-binding site bound to the origin, but this binding could not be enhanced by ATP addition. DNase I protection assays carried out with wild-type NS1 in the presence of gamma S-ATP gave footprints which extended over 43 nucleotides on both DNA strands, from the middle of the origin bubble sequence to a position some 14 bp beyond the nick site. The DNA-binding site for NS1 was mapped to a 22-bp fragment from the middle of the 3' replication origin which contains the sequence ACCAACCA. This conforms to a reiterated motif (ACCA)2-3, which occurs, in more or less degenerate form, at many sites throughout the minute virus of mice genome (J. W. Bodner, Virus Genes 2:167-182, 1989). Insertion of a single copy of the sequence (ACCA)3 was shown to be sufficient to confer NS1 binding on an otherwise unrecognized plasmid fragment. The functions of NS1 in the viral life cycle are reevaluated in the light of this result.     

Cognitive distortion and depression in chronic pain: Association with diagnosed disorders.

Previous studies have demonstrated that cognitive distortion is associated with increased levels of self-reported depression among chronic pain patients, suggesting that cognitive models of depression might be useful in this context. However, reliance on self-reports of depression hampers generalization of these results to clinically significant depressive disorders. To address this problem, we examined the association between depression diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) (i.e., major depression and dysthymia) and scores on the Cognitive Errors Questionnaire. Depressed chronic pain patients and depressed nonpain patients reported more cognitive distortion than did nondepressed pain patients and normal controls. These results support the relevance of cognitive theory in the explication of clinically significant depression among chronic pain patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of survival among hemodialysis patients: Effect of perceived family support.

The authors examined the role of perceived family support and symptoms of depression as predictors of survival in a sample of 78 in-center hemodialysis patients. Cox regression analysis revealed significant effects for family support (ppp     

Analysis of functional groups in amino resins

Aiming at establishing recommended methods for the analysis of functional groups in amino resins, four tentative methods have been tested in an international cooperative exercise. The methods were employed on four model compounds and three commercial amino resin solutions. ¹³C-NMR spectroscopy was additionally employed by two of the participants.

The inter-laboratory analytical study has resulted in four recommended methods: 1. Solvent removal from amino resins, 2. Proton-NMR spectroscopy, 3. Alkoxy group analysis by transetherification plus G.L.C., 4. Alkoxy group analysis by Zeisel/Merz cleavage plus G.L.C. The recommended methods are improved versions of the tentative methods applied in the round robin and possible future inter-laboratory exercises will probably show a reduced variation between laboratories as far as quantitative results are concerned. As to qualitative analysis of amino resins, ¹³C-NMR spectroscopy has been shown to be a powerful technique.