Longitudinal study of Staphylococcus aureus genotypes isolated from bovine clinical mastitis.

Bovine clinical mastitis is an important problem for the dairy industry, and Staphylococcus aureus is a common mastitis-causing pathogen in many countries. Detailed knowledge on genetic variation of Staph. aureus strains within the bovine population, including changes over time, can be useful for mastitis control programs, because severity of disease and effects on milk production are at least partly strain-associated. Therefore, the major aim of this study was to compare sequence types of Staph. aureus isolated from cases of bovine clinical mastitis from 2002 to 2003 with sequence types of a more recent set of isolates collected from 2013 to 2018, using core genome multi-locus sequence typing (cgMLST). We also wanted to compare antibiotic resistance genes of isolates from the 2 sets, to identify changes that may have occurred over time in the Staph. aureus population. A total of 157 isolates of Staph. aureus, almost equally distributed between the 2 time periods, were subjected to high-throughput sequencing and cgMLST. The results showed that the most prevalent sequence types found among the 2002 to 2003 isolates belonged to the clonal complexes CC97, CC133, and CC151, and that those complexes still dominated among the isolates from 2013 to 2018. However, a population shift from CC133 to CC97 and CC151 over time was observed. Likewise, no important differences in prevalence of antibiotic resistance genes were found between the 2 sets of isolates. As expected, genes belonging to the major facilitator superfamily of transporter proteins, and multidrug and toxic compound extrusion transporters, were very common. Moreover, several genes and mutations conferring resistance to fosfomycin were present, but not in CC97 isolates. The ß-lactamase gene blaZ was found in only 3 out of 81 isolates from 2002 to 2003 and 1 out of 76 isolates in 2013 to 2018. In conclusion, the results indicate that mastitis-associated Staph. aureus strains circulating among dairy cows in Sweden exhibit a remarkable genotypic persistence over a time frame of close to 15 yr.

Warmer waters masculinize wild populations of a fish with temperature-dependent sex determination.

Southern flounder (Paralichthys lethostigma) exhibit environmental sex determination (ESD), where environmental factors can influence phenotypic sex during early juvenile development but only in the presumed XX female genotype. Warm and cold temperatures masculinize fish with mid-range conditions producing at most 50% females. Due to sexually dimorphic growth, southern flounder fisheries are dependent upon larger females. Wild populations could be at risk of masculinization from ESD due to globally increasing water temperatures. We evaluated the effects of habitat and temperature on wild populations of juvenile southern flounder in North Carolina, USA. While northern habitats averaged temperatures near 23 °C and produced the greatest proportion of females, more southerly habitats exhibited warmer temperatures (>27 °C) and consistently produced male-biased sex ratios (up to 94% male). Rearing flounder in the laboratory under temperature regimes mimicking those of natural habitats recapitulated sex ratio differences observed across the wild populations, providing strong evidence that temperature is a key factor influencing sex ratios in nursery habitats. These studies provide evidence of habitat conditions interacting with ESD to affect a key demographic parameter in an economically important fishery. The temperature ranges that yield male-biased sex ratios are within the scope of predicted increases in ocean temperature under climate change.

Missing voices: Profile and extent of acquired communication disorders in Aboriginal and non-Aboriginal adult stroke survivors in Western Australia using linked administrative records.

BACKGROUND: Limited data exist on the extent of specific functional sequelae, including acquired communication disorder, among Aboriginal stroke survivors, making planning of multidisciplinary services difficult. AIMS: To obtain estimates of the extent and profile of acquired communication disorder in Aboriginal and non-Aboriginal adult stroke survivors in Western Australia and investigate potential disparities in receiving in-hospital speech pathology services among survivors with acquired communication disorder. METHODS: Stroke cases surviving their first stroke episode during 2002-2011 were identified using Western Australia-wide person-based linked hospital and mortality data, and their five-year comorbidity profiles determined. The mid-year prevalence of stroke cases with acquired communication disorder was estimated for 2011. Regression methods were used to investigate determinants of receiving speech pathology services among acquired communication disorder cases. RESULTS: Of 14,757 stroke survivors aged 15-79 years admitted in 2002-2011, 33% had acquired communication disorder (22% aphasia/dysphasia) and 777 (5.3%) were Aboriginal. Aboriginal patients were more likely to be younger, live remotely, and have comorbidities. A diagnosis of aphasia was more common in Aboriginal than non-Aboriginal patients 15-44 years (p = 0.003). A minimum of 107 Aboriginal and 2324 non-Aboriginal stroke patients with acquired communication disorder lived in Western Australia in 2011. Aboriginal status was not associated with receiving in-hospital speech services among acquired communication disorder patients in unadjusted or adjusted models. CONCLUSIONS: The relative youth, geographical distribution, high comorbidity prevalence, and cultural needs of Aboriginal stroke patients with acquired communication disorder should inform appropriate service design for speech pathology and rehabilitation. Innovative models are required to address workforce issues, given low patient volumes.

Psychosocial factors at work and blood-borne exposure among nurses.

BACKGROUND: Exposure to human blood and body fluids is a common risk for nurses. Many factors can affect the prevalence and incidence of this occupational hazard. Psychosocial factors at work may be a risk factor for the exposure. OBJECTIVE: To assess needle stick, sharp injury and mucus exposure to blood-borne pathogens among nurses in Iran and to determine the association between these exposures and psychosocial factors at work. METHODS: A cross-sectional study was conducted on nurses in a public hospital, Tehran, Iran. 364 nurses received and 339 completed and returned a self-reported questionnaire containing demographic data, history of exposure to blood-borne pathogens at work during previous year and the General Nordic questionnaire for psychological and social factors at work (QPS Nordic 34+ Questionnaire). RESULTS: Of 339 participants, 197 (58.1%) reported needle-stick injury, 186 (54.6%) reported another type of sharp injury, and 112 (33%) reported a mucous membrane exposure during the previous year. More than half of the participants who had history of exposure, had not reported it. Those with middle or high level of stress had higher crude and adjusted odds than those with lower stress for all kinds of exposure. Adjusted odds ratios for high stress group (ranging from 2.8 to 4.4) were statistically different from 1. CONCLUSION: There is a high prevalence of needle-stick and sharp injury and mucous membrane exposure to patients' blood or body fluids among studied nurses. There is a significant association between increasing psychosocial factors at work and exposure to blood-borne pathogens among this group of nurses.

[Management of isolated optic neuritis in France: survey of neurologists and ophthalmologists]. / Prise en charge des névrites optiques isolées en France: enquête auprès des neurologues et des ophtalmologistes.

BACKGROUND: Acute isolated optic neuritis is often the first manifestation of multiple sclerosis (MS). Despite the results of several clinical trials its management remains controversial. With the advent of new disease-modifying agents for the treatment of MS, management of isolated optic neuritis has become more complicated. The goal of this study was to evaluate the current clinical practice of French ophthalmologists and neurologists in the management of acute isolated optic neuritis, and to evaluate the impact of recently published randomized clinical trials on their practice. METHODS: A survey, including 24 questions on the diagnosis and treatment of acute isolated optic neuritis was sent to all neurologists and to a sample of ophthalmologists in France. RESULTS: The responses of 655 neurologists and 141 ophthalmologists were analyzed. This study shows mostly that patients initially present more frequently to ophthalmologists, and are subsequently referred to neurologists. Most optic neuritis patients undergo a brain MRI and a lumbar puncture. Although most patients receive high dose intravenous steroids, up to 15% of neurologists and 21% of ophthalmologists still recommend oral prednisone (1 mg/kg per day). Steroids are often prescribed for the wrong reason, including to improve final visual acuity or decrease the risk of MS. Disease modifying agents are sometimes prescribed outside of the official French recommendations. CONCLUSION: The evidence-based guidelines are only partially followed by practitioners managing patients with acute optic neuritis.

A 10-year retrospective audit of consecutively completed orthodontic treatments in a general dental practice and a hospital orthodontic department.

During 1993 and 1994, the author took part in the South West Orthodontic Clinical Assistant Training Programme and worked as a part-time Clinical Assistant in the Orthodontic Department of the Royal United Hospital, Bath. Following the clinical assistantship the author continued to treat patients in the hospital department but under a General Dental Services contract number. This paper is a personal clinical audit of all the orthodontic cases completed within the GDS by the author since 1990, both in general practice in Westbury, Wiltshire and at the Royal United Hospital (RUH), Bath. The aim of the audit was to evaluate the effectiveness of orthodontic treatment carried out by the author, both in general dental practice and in a hospital orthodontic department, and to compare treatment outcomes with other published results.

The practice characterization model: the importance of organizational life cycles and targeted interventions in general medical practice.

In response to a climate of constant change and increasing demand for services, general practice in the UK has undergone significant modification over the last 10 years. It has become a multi-disciplinary organisation encouraged by funding bodies to plan for service delivery using a more structured team based approach. In Tayside in 1996, practices were charged with producing formal Practice Development Plans (PDPs) which would focus on priority areas aligned with the Health Boards own strategic plan--those were teamwork, information management and technology, and clinical service delivery. The University of Dundee's Department of General Practice successfully applied for funding to develop ways of facilitating practices so that they could a) identify their own development priorities, and b) plan and implement action and learning to see these priorities through. Using action research methodology, the project attempted to create a climate for change, provide support and training to see the changes implemented, and ensure commitment to the changes from all members of the practice team. The Facilitator adopted a flexible style varying her role between expert, guide and support. Analysis of progress made by different practices, coupled with the Facilitator's in depth knowledge of them, suggested the importance of certain key aspects of practice organisation and culture. A practice characterisation model identified practices which were stable, currently coping, proactive and ready to face the challenge of change as best placed to engage in a full scale development programme. Other profiles suggested a range of alternative interventions as more likely to be acceptable and productive.

Prioritizing back injury risk in hospital employees: application and comparison of different injury rates.

To identify high risk areas for back injury in a large teaching hospital, we calculated standard injury rates and newly developed composite statistics for nursing and non-nursing work groups. Data were extracted from the hospital's workers' compensation database. The hospital-wide total injury rate was 4.6 reports per 100 full-time equivalents (FTE); Compensation Case Rate, 1.4 cases per 100 FTE; Compensation Severity Rate, 76 days lost per 100 FTE; and the Cost Rate, $3742 per 100 FTE. The Total Injury Reports Rate for nursing varied from 14.2 per 100 FTE for Intensive Care Unit (ICU) Nursing to 3.8 per 100 FTE for Pediatric Nursing. Non-nursing areas also demonstrated increased rates for back injury. Individual statistical rates ranked areas differently in risk, whereas composite statistical measures consistently ranked ICU Nursing, Buildings and Grounds, and Orthopedics/Neurological Nursing as the top three. Patient handling was the precipitating event in the majority of nursing back injuries, indicating the need for ergonomic intervention. The use of combined statistical measures provided a more integrative measure for describing and following back injury risk over time.

Effect of local sequence inversions on the crystalline antiparallel beta-sheet lamellar structures of periodic polypeptides: implications for chain-folding.

The crystal structure and texture of the monodisperse periodic polypeptide [(AG)3EG(GA)3EG]10 (poly(+/-AG)3EG: A=alanine, G=glycine, E=glutamic acid) were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, and electron microscopy. Structure determination was aided by comparison with the recently described structure for the related periodic polypeptide [(AG)3EG]36 by Krejchi et al. (Macromolecules 1997;30:5012). Texture-oriented samples of poly(+/-AG)3EG were obtained by crystallization of the polymer from aqueous formic acid solution. The evidence supports an antiparallel (ap) beta-sheet protein structure and the X-ray diffraction signals index on an orthorhombic unit cell with parameters: a=0.950 nm (hydrogen-bond direction), b=1.052 nm (apbeta-sheet stacking direction), c=6.95 nm (chain direction). The absence of the (010) diffraction signal, a prominent signal in the poly(AG)3EG diffraction pattern, implies that the apbeta-sheets are 'apolar', i.e. both surfaces are equally populated with alanyl methyl groups. Selective line broadening of wide-angle diffraction signals with l not equal to 0 gives an estimated crystal size of approximately/= 4 nm in the chain direction. This observation, coupled with the appearance of low-angle particle interference peaks, indicates a crystal thickness considerably less than the chain length and suggests an adjacent-re-entry chain-folded lamellar structure incorporating the apbeta-sheet architecture. The polypeptide folds through gamma-turns, in-phase with the pseudo-octapeptide repeat; the glutamic acid residues occur on the lamellar surfaces. These results and those from the crystalline lamellae of poly(AG)3EG suggest that beta-turns are not compatible with these repetitively stacked apbeta-sheet structures. This implies that intersheet interactions of alanyl methyl groups and glycyl alpha-protons are not sufficiently strong to dictate the folding geometry in these structures.

Investigation of glass-ionomer cements using differential scanning calorimetry.

Six commercial glass-ionomer cements commonly used for various dental applications have been investigated using differential scanning calorimetry (DSC). The heat-flow behaviour and heat capacity of the cements were measured during isothermal (at 37 degrees C) setting reactions. The DSC results show that all materials undergo an exothermic setting process, but with different enthalpies of reactions and different heat capacities; there are no remaining endo- or exothermic reactions after the setting of the cement. All materials examined were found to be effective thermal insulators.

Methods of prioritizing and measuring occupational health risks utilizing hospital back injury data. Development of composite comparative statistics.

The employee health service of a Boston hospital wanted a method to prioritize the risk of occupational injury or illness among its employees as the first step in developing a comprehensive ergonomics program. Data from the safety office and workers' compensation third-party administrator (TPA) was combined with hospital payroll data to create rates that compared all work areas based on the common denominator of 100 full-time equivalents (FTE). Rates for four different aspects of injury experience were calculated: incidence of total reported injuries, incidence of serious injuries, level of severity of injuries, and cost. The use of these simple rates alone was inadequate to accurately prioritize risk. Because most work areas ranked differently from one rate scale to the next, it was unclear which, if any, single rate most accurately defined risk. Composite statistics that combined all of the rates were needed. The Composite Risk Indicator (CRI), the Average Relative Risk (ARR), and the Justified Average Relative Risk (JARR) were developed and examined for their utility. The JARR emerged as the best choice in this setting because it captured all available information about injury or illness experience and provided a meaningful single indicator of risk that could be followed over time.

Soleus neurectomy for dynamic ankle equinus in children with cerebral palsy.

Problems with the gastrocnemius-soleus muscle group can severely impair the gait of children with cerebral palsy. Treatments, including bracing, muscle lengthening, neurectomy, or a combination, have been used with mixed results. Soleus neurectomy was performed as the primary treatment for ankle clonus in 38 legs of 21 children with a variety of cerebral palsies. Concurrent heel cord or muscle lengthening was performed if needed. Patients were followed for an average of 9 years (range, 2 to 14 years). Clonus recurred in 4 treated ankles. In 2 cases, this was due to a nerve anomaly. Postneurectomy Achilles tendon lengthening was required in 8 of the treated ankles. Neurectomy was beneficial for 19 of 21 children. Functional improvements included better control of stopping, better balance, and less toe walking. The greatest improvement was seen in those patients who did not also have heel cord contractures.

Effects of amino acid side-chain volume on chain packing in genetically engineered periodic polypeptides.

The fidelity of bacterial protein synthesis allows the production of architecturally well-defined polymeric materials through precise control of chain length, sequence, stereochemistry, and interchain interactions. In the present paper, we examine the relation between amino acid residue volume and crystalline unit cell dimensions, in a set of periodic protein polymers of repeating unit sequence -(AlaGly)3-X-Gly-, where X is Asn, Phe, Ser, Val, or Tyr. The proteins were overexpressed in Escherichia coli, purified by simple procedures based on acid/ethanol precipitation or insolubility in aqueous sodium dodecyl sulfate, and processed to form oriented crystalline mats by precipitation from formic acid under mechanical shear. X-ray diffraction analyses revealed that the basic structures of the -(AlaGly)3-X-Gly- polymers are identical to that previously reported for [(AlaGly)3-GluGly]36, [Krejchi, M.T., Atkins, E.D.T., Waddon, A.J., Fournier, M.J., Mason, T.L., and Tirrell, D.A. (1994) Science 265, 1427-1432], with the oligoalanylglycine segments forming antiparallel beta-sheets and the substituted amino acids occurring within three-residue folds at the lamellar surfaces. The X-ray diffraction signals for each member of the family index on an orthorhombic unit cell; the a-axis (hydrogen bond direction) and c-axis (chain direction) spacings remain invariant but the b-axis (sheet stacking direction) spacing increases with increasing volume of the substituted amino acid. The results obtained from a variant with alternating Glu and Lys substitution at the X position, together with the results previously reported for poly(L-alanylglycine) [Panitch, A., Matsuki, K., Cantor, E.J., Cooper, S.J., Atkins, E.D.T., Fournier, M.J., Mason, T.L., and Tirrell, D.A. (1997) Macromolecules 30, 42-49] are included for comparison. The average intersheet stacking distance (b/2) increases linearly with the volume of the amino acid inserted at position X. Because the chain-folded lamellar architecture adopted by these periodic polypeptides accommodates a wide range of residues differing in charge, steric bulk, and hydrophobicity, these results illustrate a new approach to the engineering of intermolecular interactions in polymeric solids.

Chemical sequence control of beta-sheet assembly in macromolecular crystals of periodic polypeptides.

A family of uniform periodic polypeptides has been prepared by bacterial expression of the corresponding artificial genes, with the objective of exploring the potential for control of supramolecular organization in genetically engineered protein-based polymeric materials. The repeating units of the polypeptides consist of oligomeric alanyl-glycine sequences interspersed with glutamic acid residues inserted at intervals of 8 to 14 amino acids. Crystallization of such materials from formic acid produces beta-sheet structures in the solid state, as shown by vibrational spectroscopy, nuclear magnetic resonance spectroscopy, and wide-angle x-ray diffraction. The diffraction results, together with observations from electron microscopy, are consistent with the formation of needle-shaped lamellar crystals whose thickness is controlled by the periodicity of the primary sequence. These results can be used to control solid-state structure in macromolecular materials.

Elongational flow studies on type IV collagen: comparison with type I.

Elongation flow techniques have been used to investigate the birefringent response of monodisperse type IV collagen in dilute solution and the results compared with type I collagen. A four-roll mill apparatus was used to characterize the solutions at low strain rates, epsilon < or = 300 s-1. The birefringence is nonlocalized and rises gradually to a plateau value, in accordance with rigid-rod behavior. The gradients of the tangent to the curves at zero strain rate are estimated for types IV and I collagen. The concentrations of the solutions used were in the dilute to semidilute regimes. Using a value of 300 nm for the length of type I collagen, values of 364-408 nm were calculated for the length of the type IV collagen molecule, depending on the concentration regime chosen, which is consistent with biochemical predictions based on a rigid molecule. The results imply that the behavior of type IV collagen molecules in solution is similar to type I collagen, despite the presence of several sequence interruptions in the type IV helix.

Continuing education in the physician's office: a pilot study for breast exams.

In response to a recent study indicating that primary care physicians were interested in receiving breast-screening education, an office-based training program was developed and delivered to fourteen physicians in Vermont and Florida. A nonphysician trainer and simulated patient provided instruction and feedback in clinical breast examination and in patient instruction in breast self-examination. Measurements of physician palpation skills before and after the training showed substantial skill improvement, and the office-based session was found to be highly acceptable by all participants.

Molecular bending and networks in a basement membrane-like collagen: packing in dogfish egg capsule collagen.

Low-angle X-ray diffraction data have been obtained from three mutually perpendicular axes through sheets of the collagenous egg capsule of the dogfish Scyliorhinus caniculus, a collagen that resembles type IV collagen. The data are interpreted in the light of the body of knowledge of the structure derived from transmission electron microscopy by Knight and Hunt. A model to account for the X-ray data is proposed incorporating the main dimensions of the Knight and Hunt model which are confirmed by the diffraction data. Several features of the diffraction patterns are not explained by the existing model however, and a new model is proposed to account for these features. This consists of antiparallel packed pairs of two mutually parallel molecules, each kinked and rotated so as to produce a four-fold helix resembling a crankshaft. This has the advantage of conferring intermolecular linkage in three dimensions throughout the structure with tetragonal symmetry and unit dimensions a = b = 22.6 nm, c (fibre axis direction) = 39.3 nm. The result is a fairly rigid open polygonal network or sponge-like architecture that is capable of accommodating large quantities of water and other molecules.