Does delay to theatre for medical reasons affect the peri-operative mortality in patients with a fracture of the hip?

We have investigated how medical postponement, the time to surgery and the correction of medical abnormalities, according to McLaughlin criteria, before operation affected peri-operative mortality after fracture of the hip. From February to December 2007, in addition to core data, the Scottish Hip Fracture Audit collected information relating to surgical delay. Data were available for 4284 patients which allowed 30-day survival analysis to be performed. Multivariable logistic regression models were used to control for differences in case-mix.

Patients with major clinical abnormalities were more likely to have a postponement and had a lower unadjusted 30-day survival. The time to operation and postponement were not associated with higher mortality after adjustment for case-mix. Correction of major clinical abnormalities before surgery improved the adjusted survival, but this improvement was not significant (p = 0.10). Postponement without correction of a medical abnormality before surgery was associated with a significantly lower (p = 0.006) 30-day adjusted survival. The possible benefits of postponement need to be weighed against prolonged discomfort for the patient and the possibility of the development of other complications.

Baseline sputum time to detection predicts month two culture conversion and relapse in non-HIV-infected patients

BACKGROUND

Few biomarkers are available to identify tuberculosis (TB) patients at risk of delayed sputum conversion and relapse.

OBJECTIVES

To investigate whether baseline pre-treatment time to detection (TTD) of culture predicted 2-month bacteriological conversion and TB relapse.

METHODS

A total of 263 non-HIV-infected smear-positive previously untreated pulmonary TB patients were prospectively followed from diagnosis until treatment outcome after 6 months' treatment and TB recurrence within 24 months.

RESULTS

The median TTD was 3 days (range 1-17). Of 211 (80.2%) patients with favourable treatment outcome, 22 (10.4%) had recurrence, while 12 (5.7%) had confirmed relapse. Culture conversion at 2 months was associated in univariate analysis with the presence and number of cavities, extensive parenchymal involvement, male sex, sputum smear grading and TTD. In multiple logistic regression, TTD or smear grading and extensive parenchymal involvement both predicted month 2 conversion. Relapse was predicted by TTD, sex, body mass index, smear grading and number of cavities in univariate analysis, and in multivariate regression by TTD and sputum smear grading.

CONCLUSIONS

Baseline TTD and smear grading predicted month 2 culture conversion, relapse and also recurrence. These markers may be useful to identify non-HIV-infected patients at risk of recurrence, and may be relevant in clinical trials.

Changes in population demographics and the future incidence of hip fracture

BACKGROUND

During the first three decades of the 21st century the combination of increasing life expectancy and falling birth rates will result in substantial demographic changes within the population of the United Kingdom. A large increase in the elderly population is likely to have significant effects on the number of patients who sustain a hip fracture.

AIM

To predict future changes in hip fracture burden in Scotland.

MATERIALS AND METHODS

Data was obtained from the Scottish Hip Fracture Audit database for a 12 month period between April 2004 and March 2005. All orthopaedic units in Scotland participated in the audit during this period. This data was used to calculate the incidence of hip fracture by 5 year age/gender cohorts. Outcome data was analysed in a similar manner. Population prediction data obtained from the Registrar General's Office was then used to predict hip fracture numbers for the year 2031. Two separate prediction models were used. The first model assumed that the age/gender specific incidence of hip fracture observed in 2004 would remain constant. Between 1999 and 2004, a 9.6% decrease in the population incidence of hip fracture was observed. Therefore a second prediction model was used which assumed a continuation in the fall in population incidence of hip fracture between 2004 and 2031.

RESULTS

The population aged 50 years and above is predicted to increase 28% by 2031, with the most significant increases occurring in the over 1980s. The number of hip fractures is predicted to rise by 45% to 75% (from 6164 to 8829-10756 cases per annum) requiring an additional 287-474 hospital beds. By 2031 approximately 45% of fractures will occur in those aged 85 years and above, compared to 34% in 2004. Predicted changes in population demographics are highly variable by region and so local planning of resource provision will be essential.

CONCLUSION

Changes in population demographics will have significant implications for health care provision for the care of hip fracture patients. An increase in the capacity of acute orthopaedic care and a review of care models will be required to ensure adequate resource provision.

Early mortality after surgical fixation of hip fractures in the elderly

We investigated the relationship between a number of patient and management variables and mortality after surgery for fracture of the hip. Data relating to 18 817 patients were obtained from the Scottish Hip Fracture Audit database. We divided variables into two categories, depending on whether they were case-mix (age; gender; fracture type; pre-fracture residence; pre-fracture mobility and ASA scores) or management variables (time from fracture to surgery; time from admission to surgery; grade of surgical and anaesthetic staff undertaking the procedure and anaesthetic technique).

Multivariate logistic regression analysis showed that all case-mix variables were strongly associated with post-operative mortality, even when controlling for the effects of the remaining variables. Inclusion of the management variables into the case-mix base regression model provided no significant improvement to the model. Patient case-mix variables have the most significant effect on post-operative mortality and unfortunately such variables cannot be modified by pre-operative medical interventions.

Outcome after surgery for the treatment of hip fracture in the extremely elderly

BACKGROUND

As a consequence of changes in population demographics, the extremely elderly represent one of the fastest growing groups in Western society. Previous studies have associated advanced age with increased mortality after hip fracture; however, this finding has not been consistent.

METHODS

The Scottish Hip Fracture Audit is a prospective, national, multicenter study that collects data on patients over the age of fifty years who are admitted to the hospital with a hip fracture. For the present study, we used data collected from twenty-two acute-care orthopaedic units between January 1998 and December 2005. The extremely elderly cohort consisted of 919 individuals with an age of ninety-five years or more. Case-mix variables and outcomes were compared with those for a modal control group of 15,461 individuals who were seventy-five to eighty-nine years of age. Outcome measures included thirty and 120-day mortality rates, the length of the hospital stay, the place of residence, and mobility. A multivariable logistic regression model was used to compare outcomes between groups while controlling for significant case-mix variables.

RESULTS

The extremely elderly presented with poorer indicators of health status as demonstrated by higher American Society of Anesthesiologists scores. In addition, this group was less likely to be independently mobile and more likely to be in institutional care at the time of the fracture (p < 0.001). Mortality at thirty and 120 days was higher in the extremely elderly even after adjusting for case-mix variables. The extremely elderly also were less likely to return home or to return to previous levels of mobility.

CONCLUSIONS

Although the extremely elderly exhibited a higher prevalence of prefracture indicators of poor outcome, statistical control for these case-mix variables showed further age-related deterioration in survival and outcomes after surgery for the treatment of a hip fracture.

Gender differences in epidemiology and outcome after hip fracture: evidence from the Scottish Hip Fracture Audit

We report gender differences in the epidemiology and outcome after hip fracture from the Scottish Hip Fracture Audit, with data on admission and at 120 days follow-up from 22 orthopaedic units across the country between 1998 and 2005. Outcome measures included early mortality, length of hospital stay, 120-day residence and mobility. A multivariate logistic regression model compared outcomes between genders. The study comprised 25 649 patients of whom 5674 (22%) were men and 19 975 (78%) were women. The men were in poorer pre-operative health, despite being younger at presentation (mean 77 years (60 to 101) vs 81 years (50 to 106)). Pre-fracture residence and mobility were similar between genders. Multivariate analysis indicated that the men were less likely to return to their home or mobilise independently at the 120-day follow-up. Mortality at 30 and 120 days was higher for men, even after differences in case-mix variables between genders were considered.

Time to detection of Mycobacterium tuberculosis in BACTEC systems as a viable alternative to colony counting

OBJECTIVE

To investigate whether time to detection (TTD) of Mycobacterium tuberculosis in BACTEC Mycobacteria Growth Indicator Tube (MGIT) 960 and BACTEC 460 TB systems can be used as an alternative to colony-forming unit (cfu) counting.

DESIGN

A single sputum sample recovered from each of 22 patients with tuberculosis (TB) was cultured on Middlebrook 7H11 agar and in BACTEC MGIT 960 and BACTEC 460 to investigate the relationship between cfu/ml and TTD. The relationship between TTD and treatment response was investigated by culturing a single sputum sample from each of 125 patients with TB in the BACTEC 460 system and comparing TTD values with their treatment response.

RESULTS

An inverse correlation between TTD and bacterial number, as assessed by inoculum size and cfu/ml, was observed. For the 125 patients followed up during treatment, TTD values at diagnosis correlated with smear conversion rates at 2 months and treatment outcomes. Drug resistance of the infecting strain was associated with decreased killing, as indicated by the delayed increase in TTD during the first few days of treatment.

CONCLUSION

The TTD of M. tuberculosis in BACTEC MGIT 960 and BACTEC 460 TB systems is a viable alternative to colony counting. TTD in liquid culture will facilitate mycobacterial quantification, especially in the evaluation of early bactericidal activity.

Prediction of delayed treatment response in pulmonary tuberculosis: use of time to positivity values of Bactec cultures

New drugs that can shorten tuberculosis (TB) treatment and target drug resistant strains are urgently needed. A test which could predict patients at risk of a delayed response to treatment would facilitate clinical trials of new anti-tuberculosis drugs. A widely-used test for the assessment of response to treatment is sputum smear examination. Patients who are smear positive after 2 and 3 months of treatment are said to have delayed and significantly delayed treatment responses respectively. Time to positivity (TTP) values of Bactec cultures, from the first 2 weeks of treatment were used to predict delayed and significantly delayed treatment responses in patients with first time pulmonary tuberculosis. Changes in TTP values early in treatment were transformed to a response ratio (r). Values of r that were less than a threshold value (r(c)) indicated patients who were at risk of having delayed or significantly delayed response to treatment. Accuracy of prediction was sensitive to the timing of sputum sampling and adherence to therapy in the first 2 weeks. Based on TTP data from the first 2 weeks of treatment, significantly delayed treatment response could be predicted with a sensitivity of 75% and a specificity of 62% while the positive (PPV) and negative predictive values (NPV) were 14% and 97% respectively. While the high NPV indicates that a large proportion of patients with a satisfactory response to treatment can be reliably identified, the low PPV value underlines the need to use TTP in conjunction with other markers of disease activity to predict unfavourable treatment response in tuberculosis treatment.

Vitamin D receptor gene polymorphisms and sputum conversion time in pulmonary tuberculosis patients

A cohort of pulmonary tuberculosis (TB) patients in a South African admixed population was investigated to determine if the vitamin D receptor gene (VDR) polymorphisms FokI, ApaI, and TaqI are associated with TB susceptibility or time to sputum conversion, and to investigate other clinical and demographic factors affecting the rate of response to treatment. Firstly, a case-control association study of 249 TB cases and 352 healthy controls was carried out to investigate association of VDR polymorphisms with TB susceptibility. Secondly, a cohort of pulmonary tuberculosis patients with conversion times for both sputum smear (n=220) and culture (n=222) were analysed to determine factors contributing to mycobacterial resolution in sputum. Age and gender adjusted Cox regression models were constructed. Our results indicate that the extent of disease at diagnosis was predictive of both smear and culture conversion times in the final models. Smoking status and VDR genotype contributed independently to smear conversion time, with ApaI 'AA' genotype and TaqI 'T'-containing genotypes predictive of a faster response to TB chemotherapy. We did not find an association between VDR genotype and TB in the case-control study. We conclude that the time taken for an individual to convert to sputum negativity while on antituberculosis therapy can be independently predicted by the VDR genotype.

Immune markers measured before treatment predict outcome of intensive phase tuberculosis therapy

The development of a statistical model based on simple immunological markers which could predict the response to tuberculosis treatment would facilitate clinical trials of new anti-tuberculosis drugs. We have examined the ability of immunological biomarkers, measured at diagnosis and after 4 weeks of treatment, to predict sputum smear status at week 8. Eighteen tuberculosis patients with positive Ziehl-Nielsen (ZN)-stained sputum smears 8 weeks after initiation of treatment (slow response) were matched for age, gender, sputum smear grade and extent of disease on chest radiograph to 18 patients with negative sputum smears at week 8 (fast response). In addition to total white blood cell (WBC) counts and absolute lymphocyte, monocyte and neutrophil numbers, concentrations of six serum markers were measured by enzyme-linked immunosorbent assay (ELISA) in all patients (soluble interleukin-2 receptor alpha (sIL-2Ralpha), granzyme B, soluble tumour necrosis factor alpha receptors 1 and 2 (sTNF-R1 and -2), nitrotyrosine and interferon-gamma (IFN-gamma). At diagnosis, 4 biomarkers (sTNF-R1, total WBC, absolute monocyte and absolute neutrophil numbers) were significantly higher in slow response patients. At week 4, total WBC count and absolute monocyte and neutrophil numbers remained significantly higher in slow responders. Discriminant analysis of the diagnosis and week 4 data provided models for classification of slow response patients with 67% and 83% predictive accuracy. We suggest that treatment response phenotypes can be determined before the start of treatment. Reliable predictive models would allow targeted interventions for patients at risk for slow treatment response to standard tuberculosis therapy.

Production of recombinant protein Pap31 and its application for the diagnosis of Bartonella bacilliformis infection

Tropical bartonellosis is a highly fatal epidemic and endemic infectious disease that occurs throughout the communities of the Andes Mountains in South America. The disease is caused by the facultative intracellular bacteria, Bartonella bacilliformis. The emergence of bartonellosis in new geographic areas and an increase in the number of reported cases suggest the need for a rapid test for epidemiologic study and investigation of the disease burden. The objective of this research is to develop a rapid serologic diagnostic test using recombinant antigens to overcome the limitations of the current standard IFA technique for laboratory diagnosis. Western blot analysis with patient sera of whole cell lysate separated on a 2D gel identified Pap31 as a dominant antigen. PCR primers were designed according to the sequence of ATCC strain 35685 to amplify the gene coding for Pap31 from a local isolate (HOSP 800-09, Peru). The amplicon was subsequently cloned into pET24a, adding the T7 tag, and expressed in E. coli. Patient sera with different IFA titers confirmed the diagnostic band of 31 kDa on a Western blot of SDS-PAGE. The performance of affinity-purified recombinant Pap31 (rPap31) was also evaluated in an ELISA format with 137 patient sera of known IFA titers. The range of ELISA reading from positive sera did not overlap with the range of those from negative sera, suggesting the potential application of rPap31 in both ELISA for high throughput regional hospital settings and in the construction of handheld rapid tests for rural clinical sites.

An oral health education programme based on the National Curriculum

AIM

The aim of this study was to develop and evaluate a teaching programme based on the national curriculum for use in a primary school setting.

DESIGN

National Curriculum guidelines were combined with oral health education messages to draw up lesson plans for teachers to deliver. A questionnaire was used to demonstrate children's oral health knowledge prior to the teaching programme, and at 1 and 7 weeks following the programme. The study took place in inner-city, state-run primary schools in Manchester and North London, UK. The subjects were children between the ages of 7 and 8 years from Manchester (n = 58) and North London (n = 30). The main outcome measure was change in knowledge attributable to a newly developed teaching programme.

RESULTS

The children in Manchester had a higher level of knowledge prior to the teaching programme. Following the teaching programme, children in both schools showed a significant improvement in dental health knowledge (P < 0.001). Seven weeks later, the Manchester children showed no significant loss of knowledge (P < 0.001).

CONCLUSIONS

The aims of the National Curriculum were easily integrated with oral health messages. A more widely available teaching resource, such as the one described in this study, would be useful to encourage the teaching profession to take on oral health education without more costly input from dental professionals.

Aggregation of inertial particles in random flows

We consider the trajectories of particles suspended in a randomly moving fluid. If the Lyapunov exponent of these trajectories is negative, the paths of these particles coalesce, so that particles aggregate. Here we give a detailed account of a method [B. Mehlig and M. Wilkinson, Phys. Rev. Lett. 92, 250602 (2004)] for calculating this exponent: it is expressed as the expectation value of a random variable evolving under a stochastic differential equation. We analyze this equation in detail in the limit where the correlation time of the velocity field of the fluid is very short, such that the stochastic differential equation is a Langevin equation. We derive an asymptotic perturbation expansion of the Lyapunov exponent for particles suspended in three-dimensional flows in terms of a dimensionless measure of the inertia of the particles, epsilon, and a measure of the relative intensities of potential and solenoidal components of the velocity field, Gamma. We determine the phase diagram in the epsilon-Gamma plane.

Identification and validation of novel drug targets in tuberculosis

There is an urgent need for new antimycobacterial drugs, and in particular for novel agents that will shorten the duration of tuberculosis chemotherapy, or overcome drug-resistant strains of the causative organism, Mycobacterium tuberculosis. Our knowledge of the tubercle bacillus and its complex interaction with the human host has improved dramatically in recent years, particularly with the determination of its complete genome sequence. New genome-scale tools are being applied to aid in drug target identification, alongside traditional approaches aimed at understanding the basic biology of M. tuberculosis. Many potential drug targets have been identified, but very few have been validated by showing that they are essential for growth or survival of the bacterium. In this review, the landscape of potential drug targets is surveyed.Structural Bioinformatic Approaches to the Discovery of New Antimycobacterial Drugs.

The Mycobacterium tuberculosis dosRS two-component system is induced by multiple stresses

Induction of the Mycobacterium tuberculosis dosR gene, which is known to respond to hypoxia, was measured using RTq-PCR following exposure to different stresses. Increased expression was seen after exposure to S-nitrosoglutathione (GSNO), ethanol and (to a lesser extent) H2O2, but not heat- or cold-shock. We also demonstrated that hspX, which is dependent on dosR for expression, is induced when cultures are left standing for 30 min, while significant but minor induction was seen following a 10 min centrifugation. Microarray analysis was used to compare gene expression in wild-type and deltadosR strains following 30 min standing. Fifty-two genes were significantly up-regulated, and 19 genes were down-regulated. These included genes that had previously been reported as being part of the dosR regulon, and also some novel ones.

Unusual manifestations in X-linked amelogenesis imperfecta

This paper describes a female with X-linked amelogenesis imperfecta (XAI). This case is unusual in having taurodontism, pulpal calcifications, coronal defects prior to tooth eruption and unerupted teeth. These findings have been reported in some cases of autosomal dominant and autosomal recessive AI but have not previously been documented in XAI.

Galactan biosynthesis in Mycobacterium tuberculosis. Identification of a bifunctional UDP-galactofuranosyltransferase

The cell wall of Mycobacterium tuberculosis and related genera is unique among prokaryotes, consisting of a covalently bound complex of mycolic acids, D-arabinan and D-galactan, which is linked to peptidoglycan via a special linkage unit consisting of Rhap-(1-->3)-GlcNAc-P. Information concerning the biosynthesis of this entire polymer is now emerging with the promise of new drug targets against tuberculosis. Accordingly, we have developed a galactosyltransferase assay that utilizes the disaccharide neoglycolipid acceptors beta-d-Galf-(1-->5)-beta-D-Galf-O-C(10:1) and beta-D-Galf-(1-->6)-beta-D-Galf-O-C(10:1), with UDP-Gal in conjunction with isolated membranes. Chemical analysis of the subsequent reaction products established that the enzymatically synthesized products contained both beta-D-Galf linkages ((1-->5) and (1-->6)) found within the mycobacterial cell, as well as in an alternating (1-->5) and (1-->6) fashion consistent with the established structure of the cell wall. Furthermore, through a detailed examination of the M. tuberculosis genome, we have shown that the gene product of Rv3808c, now termed glfT, is a novel UDP-galactofuranosyltransferase. This enzyme possesses dual functionality in performing both (1-->5) and (1-->6) galactofuranosyltransferase reactions with the above neoglycolipid acceptors, using membranes isolated from the heterologous host Escherichia coli expressing Rv3808c. Thus, at a biochemical and genetic level, the polymerization of the galactan region of the mycolyl-arabinogalactan complex has been defined, allowing the possibility of further studies toward substrate recognition and catalysis and assay development. Ultimately, this may also lead to a more rational approach to drug design to be explored in the context of mycobacterial infections.

Effects of individual performance feedback on nurses' adherence to pain management clinical guidelines

The purpose of this study was to examine the effects of an individual performance feedback intervention on nurses' adherence to pain management practice guidelines. Thirty orthopedic staff nurses received individual performance feedback on their past performance of three recommended pain management practices. Nurses' performance of the three recommended practices significantly improved over the 15 weeks after the feedback intervention. Missed 4-hour pain assessments declined (t = 8.77, df = 239, P < 0.0001), reassessments after analgesics increased (t = -5.71, df = 239, P < 0.0001), and follow-up taken for unacceptable pain increased (t = -3.08, df = 178, P < 0.01). Results suggest that individual performance feedback may be an effective approach to improving nurses' pain management intervention activities.

Effects of performance feedback on patient pain outcomes

The purpose of this study was to examine the effects of an individual feedback intervention provided to nurses on selected patient outcomes related to postoperative pain management Individual performance feedback served as the intervention. Thirty orthopedic staff nurses received feedback information on their past performance of recommended pain management practices. Data were collected preintervention and postintervention on selected patient pain outcomes from the medical records of 240 patients who had undergone total knee arthroplasty. The patient outcome measures were mean 4-hour pain intensity ratings, mean highest pain intensity ratings, mean number of times pain ratings exceeded patients' acceptable level of pain, mean administered morphine equivalents, and mean pain ratings on reassessment following analgesia administration. An improvement was noted in all pain outcomes following the feedback intervention. Results indicate that providing nurses with feedback on their past performance of pain management practices may contribute to decreased postoperative pain.

Biotreatment of refinery spent-sulfidic caustic using an enrichment culture immobilized in a novel support matrix

Sodium hydroxide solutions are used in petroleum refining to remove hydrogen sulfide (H2S) and mercaptans from various hydrocarbon streams. The resulting sulfide-laden waste stream is called spent-sulfidic caustic. An aerobic enrichment culture was previously developed using a gas mixture of H2S and methyl-mercaptan (MeSH) as the sole energy source. This culture has now been immobilized in a novel support matrix, DuPont BIO-SEP beads, and is used to bio-treat a refinery spent-sulfidic caustic containing both inorganic sulfide and mercaptans in a continuous flow, fluidized-bed column bioreactor. Complete oxidation of both inorganic and organic sulfur to sulfate was observed with no breakthrough of H2S and < 2 ppmv of MeSH produced in the bioreactor outlet gas. Excessive buildup of sulfate (> 12 g/L) in the bioreactor medium resulted in an upset condition evidenced by excessive MeSH breakthrough. Therefore, bioreactor performance was limited by the steady-state sulfate concentration. Further improvement in volumetric productivity of a bioreactor system based on this enrichment culture will be dependent on maintenance of sulfate concentrations below inhibitory levels.

A putative ubiquitin ligase required for efficient mRNA export differentially affects hnRNP transport

BACKGROUND

In the nucleus, mRNAs are bound by hnRNP proteins. A subset of hnRNP proteins shuttle between the nucleus and cytoplasm and are believed to promote mRNA export by acting as adaptors between mRNA and the transport machinery. The existence of multiple shuttling hnRNP proteins raises the question of whether differentially regulated, hnRNP-specific mRNA export pathways exist.

RESULTS

We have determined that Tom1p, a conserved protein with a hect (homology to E6-AP carboxyl terminus) E3 ubiquitin ligase domain, is required for efficient mRNA export in S. cerevisiae, yet differentially affects hnRNP protein localization and export. Mutations in tom1 predicted to abolish ubiquitin ligase activity block efficient export of Nab2p and mRNA, causing Nab2p-mRNA complexes to accumulate in a punctate pattern coincident with the nuclear pore complex (NPC). Notably, the subcellular distribution of several other hnRNP proteins is not affected. In particular, Np13p remains mRNA-associated and continues to be efficiently exported in tom1 mutants.

CONCLUSION

Our results demonstrate that mutations predicted to affect the enzymatic activity of the Tom1p ubiquitin ligase differentially affect export of hnRNP proteins in association with mRNA. We propose the existence of multiple mRNA export pathways, with export of Nab2p-associated mRNAs dependent on a branch of the ubiquitin protein modification pathway.