Specific N-terminal interactions of the Escherichia coli SeqA protein are required to form multimers that restrain negative supercoils and form foci

The Escherichia coli SeqA protein binds preferentially to hemimethylated DNA and is required for inactivation (sequestration) of newly formed origins. A mutant SeqA protein, SeqA4 (A25T), which is deficient in origin sequestration in vivo, was found here to have lost the ability to form multimers, but could bind as dimers with wild-type affinity to a pair of hemimethylated GATC sites. In vitro, binding of SeqA dimers to a plasmid first generates a topology change equivalent to a few positive supercoils, then the binding leads to a topology change in the "opposite" direction, resulting in a restraint of negative supercoils. Binding of SeqA4 mutant dimers produced the former effect, but not the latter, showing that a topology change equivalent to positive supercoiling is caused by the binding of single dimers, whereas restraint of negative supercoils requires multimerization via the N-terminus. In vivo, mutant SeqA4 protein was not capable of forming foci observed by immunofluorescence microscopy, showing that N-terminus-dependent multimerization is required for building SeqA foci. Overproduction of SeqA4 led to partially restored initiation synchrony, indicating that origin sequestration may not depend on efficient higher-order multimerization into foci, but do require a high local concentration of SeqA.     

In situ fixation of slipped capital femoral epiphysis with Steinmann pins

Background and purpose

Slipped capital femoral epiphysis (SCFE) is often treated by surgical fixation; however, no agreement exists regarding technique. We analyzed the outcome of in situ fixation with Steinmann pins.

Patients and methods

All 67 subjects operated for slipped capital femoral epiphysis at Haukeland University Hospital during the period 1990–2007 were included. All were treated by in situ fixation with 2 or 3 parallel Steinmann pins (8 mm threads at the medial end). The follow-up evaluation consisted of clinical examination and hip radiographs. Radiographic outcome was based on measurements of slip progression, growth of the femoral neck, leg length discrepancy, and signs of avascular necrosis and chondrolysis.

Results

67 subjects (41 males) were operated due to unilateral slips (n = 47) or bilateral slips (n = 20). Mean age at time of diagnosis was 13 (7.2–16) years. Mean age at follow-up was 19 (14–30) years, with a mean postoperative interval of 6.0 (2–16) years. The operated femoral neck was 9% longer at skeletal maturity than at surgery, indicating continued growth of the femoral neck. At skeletal maturity, 12 subjects had radiographic features suggestive of a previous asymptomatic slip of the contralateral hip. The total number of bilateral cases of SCFE was 32, i.e half of the children had bilateral SCFE. 3 subjects required additional surgery and mild avascular necrosis of the femoral head was seen in 1 patient. None had slip progression or chondrolysis.

Interpretation

In situ pinning of SCFE with partly threaded Steinmann pins appears to be a feasible and safe method, with few complications. The technique allows further growth of the femoral neck.Slipped capital femoral epiphysis (SCFE) is a disease of unknown etiology, but mechanical, biological and hereditary factors are likely to play a role (Barrios et al. 2005, Murray and Wilson 2008). The rationale for treatment of SCFE is to restore hip function, prevent further slip, and to reduce the risk of subsequent degenerative changes. Several surgical techniques have been recommended such as cannulated screws (Chen et al. 2009), hook-pins (Hansson 1982), specially constructed screws (Wensaas and Svenningsen 2005), and most recently surgical hip dislocation with subcapital correction osteotomy (Leunig et al. 2007). However, currently there is no evidence to support the superiority of one particular technique over another.In situ fixation is advocated by most authors (Boyer et al. 1981, Carey et al. 1987, Givon and Bowen 1999) since peroperative reduction may increase the risk of avascular necrosis (Ordeberg et al. 1983, Carney et al. 1991, Lim et al. 2007). Physiodesis to prevent further growth—thus stabilizing the physis—is recommended by some authors (Carey et al. 1987, Aronsson and Karol 1996). Slip of the contralateral hip is reported in more than half of the cases (Hägglund et al. 1988, Castro et al. 2000) and controversies exist regarding prophylactic fixation of the contralateral hip. According to Jerre et al. (1994), more than two-thirds of the contralateral slips are asymptomatic and are therefore only detected at close follow-ups including hip radiographs at short intervals. Immediate prophylactic fixation of the contralateral hip has been advocated by several authors (Hägglund et al. 1988, Schultz et al. 2002, Krauspe et al. 2004).In this paper, we present clinical and radiographic results of a novel, simple technique for in situ fixation of the femoral head with partially threaded Steinmann pins to enable further growth of the femoral neck.     

Antenatal clinic-based HIV prevalence in Zambia: declining trends but sharp local contrasts in young women

OBJECTIVES: To describe regional variation in human immunodefffeciency virus (HIV) prevalence trends in the period 1994-2002 and to assess the effects on prevalence trends of residence, educational level and age, and potential interaction between these variables. METHODS: The data were from the national HIV sentinel surveillance system comprising information collected using interviews and unlinked anonymous testing of blood among pregnant women attending antenatal clinics in 22 sites in 1994, 1998 and 2002. RESULTS: There was a decline in HIV prevalence in the age group 15-24 years in the period 1994-2002 both in rural (by 11%) and urban (by 26%) areas. The decline was strongest among highly educated women. However, this overall decline masked striking differences at community (site) levels with clearly declining epidemics in many sites contrasted by increasing epidemics in some and stability in others. Urban/rural residence, age, educational attainment, marital status and parity were factors closely associated with HIV infection. Having born many children was associated with lower risk of being infected by HIV, even in the age group 15-24. CONCLUSIONS: The HIV prevalence decline in young women is likely to reflect a drop in incidence during the period. However, there were sharp geographical contrasts in trends. Such local contrasts probably indicate differences in effectiveness of preventive interventions. Understanding factors and mechanisms explaining the differences will be of critical importance to better guide preventive interventions.     

A co-operative evaluation of different methods of detecting BCR-ABL kinase domain mutations in patients with chronic myeloid leukemia on second-line dasatinib or nilotinib therapy after failure of imatinib

Background

Various techniques have been employed to detect BCR-ABL kinase domain mutations in patients with chronic myeloid leukemia who are resistant to imatinib. This has led to different reported frequencies of mutations and the finding of a heterogeneous pattern of individual mutations.

Design and Methods

We compared direct sequencing alone and in combination with denaturing high-performance liquid chromatography and two high-sensitivity allele-specific oligonucleotide polymerase chain reaction approaches for analysis of BCR-ABL mutations in 200 blinded cDNA samples prior to and during second-line dasatinib or nilotinib therapy in patients with chronic myeloid leukemia in whom imatinib treatment had failed.

Results

One hundred and fourteen mutations were detected by both direct sequencing alone or in combination with high performance liquid chromatography and 13 mutations were additionally detected by the combined technique. Eighty of 83 mutations (96%) within a selected panel of 11 key mutations were confirmed by both allele-specific oligonucleotide polymerase chain reaction techniques and 62 mutations were identified in addition to those detected by combined liquid chromatography and direct sequencing, indicating the presence and a high prevalence of low-level mutations in this cohort of patients. Furthermore, 125 mutations were detected by only one allele-specific oligonucleotide polymerase chain reaction technique. Pre-existing mutations were traceable 4.5 months longer and emerging clones were detectable 3.0 months earlier by allele-specific oligonucleotide polymerase chain reaction than by direct sequencing together with liquid chromatography.

Conclusions

Our results suggest that denaturing high performance liquid chromatography combined with direct sequencing is a reliable screening technique for the detection of BCR-ABL kinase domain mutations. Allele-specific oligonucleotide polymerase chain reaction further increases the number of detected mutations and indicates a high prevalence of mutations at a low level. The clinical impact of such low-level mutations remains uncertain and requires further investigation. Allele-specific oligonucleotide polymerase chain reaction allows detection of defined mutations at a lower level than does denaturing high performance liquid chromatography combined with direct sequencing and may, therefore, provide clinical benefit by permitting early reconsideration of therapeutic strategies.     

Rheumatology care: Involvement in medical decisions, received information, satisfaction with care, and unmet health care needs in patients with rheumatoid arthritis and ankylosing spondylitis

OBJECTIVE: To examine levels of received information, involvement in medical decisions, and satisfaction with care, to explore factors related to current involvement in medical decisions, and to assess patients' unmet health care needs related to their disease. METHODS: A total of 1,193 patients with rheumatoid arthritis and ankylosing spondylitis completed self-reported health status questionnaires, including registration of sociodemographic data and questions about rheumatology care. Separate questions addressed information received, involvement in decisions, and satisfaction with care. Aspects of unmet health were assessed by an open-ended question. RESULTS: The majority of patients reported medium to high levels of received information, involvement in medical decisions, and satisfaction with care. High involvement in medical decisions was univariately associated with high levels of perceived information and satisfaction, as well as with lower age and a good health status. In the multivariate analyses, patient satisfaction (odds ratio [OR] 4.21) and a high level of received information (OR 7.85), age (OR 0.99), and >12 years of formal education (OR 1.46) remained as significant predictors to current involvement. Nearly one-third reported a variety of unmet health care needs, and this report was associated with poor health. CONCLUSION: The results indicate a need for a more flexible and patient centered care model, in which patients to a larger degree can decide which services they need and how these services should be delivered.     

Patient experiences of uncertainty - a synthesis to guide nursing practice and research

hansen b.s., rørtveit k., leiknes i., morken i., testad i., joa i. & severinsson e. (2012) Journal of Nursing Management 20, 266–277
Patient experiences of uncertainty – a synthesis to guide nursing practice and research Aim The aim of this study was to provide a synthesis of patients’ experiences of uncertainty in illness and the interventions outlined, based on qualitative research. Background There is a need to explore various patient experiences from a nursing perspective in order to achieve evidence-based practice and improve the quality of care. Uncertainty in illness is a dynamic experience – a stressor with a major impact on patients’ illnesses. Methods A literature search performed on PubMed and Cinahl yielded 15 qualitative studies that met the inclusion criteria and which were analysed and interpreted. Results Experienced uncertainty was one of two main areas comprising three themes: explaining, feeling and facing uncertainty. The second main area was suggested intervention strategies consisting of three themes: organizing the patient trajectory throughout the health-care system, supporting patients through relationships and providing knowledge through clear and accurate communication. Conclusion Providing insight, confidence and supporting the patients’ feeling of control are of importance for health-care professionals. Implications for nursing management Structured organization of the trajectory system should be followed up, while outcome measures (patient satisfaction), education and training programmes for patients and families after discharge to improve coping strategies and reduce uncertainty should be developed. Nurse leaders should work towards the establishment of clinical academic nursing positions to integrate knowledge, skills, experiences and research into everyday routines.     

Lung function and bronchial hyper-reactivity from 11 to 18 years in children with bronchiolitis in infancy

Background

Various trajectories for lung function and bronchial hyper-reactivity (BHR) from early childhood to adulthood are described, including puberty as a period with excessive lung growth. Bronchiolitis in infancy may be associated with increased risk of developing chronic obstructive pulmonary disease, but the development of respiratory patterns during puberty is poorly characterized for these children. We aimed to study the development and trajectories of lung function and BHR from 11 to 18 years of age in children hospitalized for bronchiolitis in infancy.

Methods

Infants hospitalized for bronchiolitis at the University Hospitals in Stavanger and Bergen, Norway, during 1997-1998, and an age-matched control group, were included in a longitudinal follow-up study and examined at 11 and 18 years of age with spirometry and methacholine provocation test (MPT). The MPT data were managed as dose-response slope (DRS) in the statistical analyses. Changes in lung function and DRS from 11 to 18 years of age were analyzed by generalized estimating equations, including interaction terms.

Results

z-scores for forced vital capacity (FVC), forced expiratory volume in first second (FEV₁), FEV₁/FVC ratio, and DRS were not different from 11 to 18 years of age in both the post-bronchiolitis and the control group. The trajectories from 11 to 18 years did not differ between the two groups. BHR at age 11 was independently associated with asthma at age 18.

Conclusion

Children hospitalized for bronchiolitis had stable predicted lung function and BHR from 11 to 18 years of age. The lung function trajectories were not different from controls.