biomArker-guided Duration of Antibiotic treatment in hospitalised Patients with suspecTed Sepsis (ADAPT-Sepsis): A protocol for a multicentre randomised controlled trial

Aim

To describe the protocol for a multi-centre randomised controlled trial to determine whether treatment protocols monitoring daily CRP (C-reactive protein) or PCT (procalcitonin) safely allow a reduction in duration of antibiotic therapy in hospitalised adult patients with sepsis.

Design

Multicentre three-arm randomised controlled trial.

Setting

UK NHS hospitals.

Target population

Hospitalised critically ill adults who have been commenced on intravenous antibiotics for sepsis.

Health technology

Three protocols for guiding antibiotic discontinuation will be compared: (a) standard care; (b) standard care + daily CRP monitoring; (c) standard care + daily PCT monitoring. Standard care will be based on routine sepsis management and antibiotic stewardship. Measurement of outcomes and costs. Outcomes will be assessed to 28 days. The primary outcomes are total duration of antibiotics and safety outcome of all-cause mortality. Secondary outcomes include: escalation of care/re-admission; infection re-lapse/recurrence; antibiotic dose; length and level of critical care stay and length of hospital stay. Ninety-day all-cause mortality rates will also be collected. An assessment of cost effectiveness will be performed.

Conclusion

In the setting of routine NHS care, if this trial finds that a treatment protocol based on monitoring CRP or PCT safely allows a reduction in duration of antibiotic therapy, and is cost effective, then this has the potential to change clinical practice for critically ill patients with sepsis. Moreover, if a biomarker-guided protocol is not found to be effective, then it will be important to avoid its use in sepsis and prevent ineffective technology becoming widely adopted in clinical practice.

Serum cortisol assay performance following the 1 mg overnight dexamethasone suppression test

BACKGROUND

The 1 mg overnight dexamethasone suppression test (ONDST) is recommended for the differential diagnosis of Cushing's syndrome and the investigation of adrenal incidentalomas. Despite documented variation in serum cortisol immunoassay performance, little has been published regarding its effect on the ONDST.

AIMS

Assess the performance of three immunoassay platforms (Roche Elecsys II, Abbott Alinity & Siemens Centaur) when compared to a liquid chromatography tandem mass spectrometry (LC-MS/MS) method.

METHODS

Samples (n = 77) sent to the laboratory as part of an ONDST were retrieved prior to disposal, anonymized, and analysed on all platforms. Samples with factors impacting immunoassay analysis quality were excluded. Results were statistically compared to an LC-MS/MS method that previously demonstrated excellent comparability to a candidate reference method.

RESULTS

The Roche gen II showed a mean bias of -2.4 nmol/L and a Passing-Bablok fit of y = -0.9 + 0.97x. This was not affected by sex. The Abbott showed a mean bias -18.8 nmol/L, and a fit of y = -11.3 + 0.88x. This bias was -20.7 nmol/L in females versus -17.2 nmol/L in males. The Siemens had a mean bias of 2.3 nmol/L and a fit of y = 1.4 + 1.07x. This bias was 5.7 nmol/L in males versus -1.0 nmol/L in females.

CONCLUSIONS

Clinicians should be aware of the method-dependent variation that exists within serum cortisol analysis during the ONDSTs. Roche and Siemens aligned more closely with LC-MS/MS while the Abbot may cause a reduction in ONDST sensitivity. This data supports assay-specific cut-offs for the ONDST.

Heterozygous CAPN3 missense variants causing autosomal-dominant calpainopathy in seven unrelated families

AIMS

Recessive variants in CAPN3 gene are the cause of the commonest form of autosomal recessive limb girdle muscle dystrophy. However, two distinct in-frame deletions in CAPN3 (NM_000070.3:c.643_663del21 and c.598_621del15) and more recently, Gly445Arg and Arg572Pro substitutions have been linked to autosomal dominant (AD) forms of calpainopathy. We report 21 affected individuals from seven unrelated families presenting with an autosomal dominant form of muscular dystrophy associated with five different heterozygous missense variants in CAPN.

METHODS

We have used massively parallel gene sequencing (MPS) to determine the genetic basis of a dominant form of limb girdle muscular dystrophy in affected individuals from seven unrelated families.

RESULTS

The c.700G> A, [p.(Gly234Arg)], c.1327T> C [p.(Ser443Pro], c.1333G> A [p.(Gly445Arg)], c.1661A> C [p.(Tyr554Ser)] and c.1706T> C [p.(Phe569Ser)] CAPN3 variants were identified. Affected individuals presented in young adulthood with progressive proximal and axial weakness, waddling walking and scapular winging or with isolated hyperCKaemia. Muscle imaging showed fatty replacement of paraspinal muscles, variable degrees of involvement of the gluteal muscles, and the posterior compartment of the thigh and minor changes at the mid-leg level. Muscle biopsies revealed mild myopathic changes. Western blot analysis revealed a clear reduction in calpain 3 in skeletal muscle relative to controls. Protein modelling of these variants on the predicted structure of calpain 3 revealed that all variants are located in proximity to the calmodulin-binding site and are predicted to interfere with proteolytic activation.

CONCLUSIONS

We expand the genotypic spectrum of CAPN3-associated muscular dystrophy due to autosomal dominant missense variants.

Chronic lung disease in adult recurrent tuberculosis survivors in Zimbabwe: a cohort study

OBJECTIVE

To examine the prevalence and magnitude of chronic lung disease (CLD) and its association with empiric anti-tuberculosis treatment (due to lack of bacteriologic confirmation) among recurrent tuberculosis (TB) survivors in a human immunodeficiency virus (HIV) prevalent setting.

METHODS

Prospective cohort study of retreatment TB survivors in Harare, Zimbabwe. At median follow-up of 2 years post-treatment initiation, we characterized mortality, respiratory impairment, and mental health.

RESULTS

Among 175 retreatment TB survivors, 65% of whom were HIV-positive and 21% had been empirically treated, multiparameter CLD was noted at follow-up among 14% of patients (95%CI 9.0-19.7), with a six-fold increase in age-adjusted death in the first year following treatment completion. Empirically treated TB (relative risk [RR] 3.4, 95%CI 1.4-8.3) was associated with CLD, as was the number of previous anti-tuberculosis treatment courses in dose-dependent fashion (three vs. one, RR 6.2, 95%CI 1.7-22.1). Among retreatment TB survivors, 33% (95%CI 26.0-40.1) had persistent respiratory symptoms (Chronic Obstructive Pulmonary Disease Assessment Test score 10); 26% (95%CI 19.8-33.0) significant deficits in exercise capacity (median incremental shuttle walk test distance, 550 m; Q₁-Q₃ 440-730 m); 83% (95%CI 75.7-89.7) residual radiographic abnormalities on chest X-ray; 12% (95%CI 6.6-16.1%) moderate-to-severe obstruction on spirometry; and 13% (95%CI 7.6-17.5%) major depression.

CONCLUSIONS

Despite successful treatment, retreatment TB survivors retain a substantial risk of morbidity and mortality.

A change in perspective to see the bigger picture. A thematic analysis of Audit and Quality Improvement submissions to the last seven UK based SAM Conferences

AIMS

To create a profile of Society for Acute Medicine (SAM) Audit and Quality Improvement (A&QI) accepted abstracts from the last seven UK based conferences.

METHODOLOGY

The profile elements for 380 SAM A&QI abstracts accepted for poster presentation were compiled from their respective conference programme booklets. Abstracts were classified into 30 categories based on key themes. Further sub-categorisation of abstracts was based on secondary detail of the submissions. Data was analysed with Pareto charts.

FINDINGS

The majority of submissions were covered by a small representation of themes, with 30% of category themes covering 80% of A&QI abstracts. There is a repetitive trend of theme categories across all the conferences.

Logistic early warning scores to predict death, cardiac arrest or unplanned intensive care unit re-admission after cardiac surgery

NHS England recently mandated that the National Early Warning Score of vital signs be used in all acute hospital trusts in the UK despite limited validation in the postoperative setting. We undertook a multicentre UK study of 13,631 patients discharged from intensive care after risk‐stratified cardiac surgery in four centres, all of which used VitalPAC^TM to electronically collect postoperative National Early Warning Score vital signs. We analysed 540,127 sets of vital signs to generate a logistic score, the discrimination of which we compared with the national additive score for the composite outcome of: in‐hospital death; cardiac arrest; or unplanned intensive care admission. There were 578 patients (4.2%) with an outcome that followed 4300 sets of observations (0.8%) in the preceding 24 h: 499 out of 578 (86%) patients had unplanned re‐admissions to intensive care. Discrimination by the logistic score was significantly better than the additive score. Respective areas (95%CI) under the receiver‐operating characteristic curve with 24‐h and 6‐h vital signs were: 0.779 (0.771–0.786) vs. 0.754 (0.746–0.761), p < 0.001; and 0.841 (0.829–0.853) vs. 0.813 (0.800–0.825), p < 0.001, respectively. Our proposed logistic Early Warning Score was better than the current National Early Warning Score at discriminating patients who had an event after cardiac surgery from those who did not.

Does kV-MV dual-energy computed tomography have an advantage in determining proton stopping power ratios in patients?

Conventional kilovoltage (kV) x-ray-based dual-energy CT (DECT) imaging using two different x-ray energy spectra is sensitive to image noise and beam hardening effects. The purpose of this study was to evaluate the theoretical advantage of the DECT method for determining proton stopping power ratios (SPRs) using a combination of kV and megavoltage (MV) x-ray energies. We investigated three representative x-ray energy pairs: 100 and 140 kVp comprised the kV-kV pair, 100 kVp and 1 MV comprised the kV-MV pair, and two 1 MV x-ray beams-one with and one without external filtration-comprised the MV-MV pair. The SPRs of 34 human tissues were determined using the DECT method with these three x-ray energy pairs. Small perturbations were introduced into the CT numbers and x-ray spectra used for the DECT calculation to simulate the effects of random noise and beam hardening. An error propagation analysis was performed on the DECT calculation algorithm to investigate the propagation of CT number uncertainty to final SPR estimation and to suggest the best x-ray energy combination. We found that the DECT method using each of the three beam pairs achieved similar accuracy in determining the SPRs of human tissues in ideal conditions. However, when CT number uncertainties and artifacts such as imaging noise and beam hardening effects were considered, the kV-MV DECT improved the accuracy of SPR estimation substantially over the kV-kV or MV-MV DECT methods. Furthermore, our error propagation analysis showed that the combination of 100 kVp and 1 MV beams was close to the optimal selection when using the DECT method to determine SPRs. Overall, the kV-MV combination makes the DECT method more robust in resolving the effective atomic numbers for biological tissues than the traditional kV-kV DECT method.

Review of the safety and efficacy of long-term NSAID use in the treatment of canine osteoarthritis

The published, peer-reviewed literature was systematically searched for information on the safety and efficacy of long-term (defined as 28 days or more of continuous therapy) NSAID use in the treatment of canine osteoarthritis. Online databases were reviewed in June 2008 and papers were selected based on their relevance. Fifteen papers were identified and evaluated. Six of seven papers indicated a benefit of long-term treatment over short-term treatment in terms of the reduction of clinical signs or lameness; one study showed no benefit. Fourteen papers evaluated safety with calculated experimental (adverse) event rates (EER) between 0 and 0.31, but there was no correlation between study length and EER (rs=-0.109, P=0.793). The balance of evidence for the efficacy of NSAIDs supports longer-term use of these agents for increased clinical effect. There is no indication in the literature that such an approach is associated with a reduction in safety, although robust data on the safety of long-term NSAID use are lacking in large numbers of dogs.

Pituitary apoplexy: retrospective review of 30 patients—is surgical intervention always necessary?

The objective of this article is to review clinical outcomes in patients presenting with pituitary apoplexy and compare the results of conservative and surgical management. It took the form of a retrospective review of 30 patients (23M, 7F; age range: 17-86 years) with pituitary apoplexy diagnosed between 1988 and 2004. Presenting features included headache in 27 patients, 'collapse' in three and vomiting in 14. Complete blindness occurred in four patients, monocular blindness in two, decreased visual acuity in 12, visual field loss in 10 and ophthalmoplegia in 15. Only five had no initial visual deficit. CT was the initial mode of imaging in 22 patients: three such scans were initially reported as 'normal' and a further 10 as pituitary tumour only, with no haemorrhage. Ten patients proceeded to early pituitary surgery and 20 were managed conservatively. There was one death 24 days after admission in a patient with multiple co-morbidities. Of the six patients with blindness, three (two conservatively treated) regained partial vision. Of the remaining 19 patients with visual deficits, 10 (two surgically treated) recovered fully and eight (four surgically treated) partly so. At latest follow-up the following pituitary hormone deficiencies were identified: ACTH 19; TSH 20; testosterone 18; ADH (diabetes insipidus) eight. Later recurrence of a pituitary adenoma was observed in seven cases (including six of the 10 surgically treated patients). There was no evidence that those patients managed surgically had a better outcome. Early neurosurgical intervention may not be required in most patients presenting with pituitary apoplexy.

Intrathecal chemotherapy delivered by a lumbar-thecal catheter in metastatic medulloblastoma: a case illustration

BACKGROUND

Medulloblastoma is the most common malignant brain tumour in children. Despite recent advances, the prognosis in high risk patients remains poor. Further improvement in survival is dependent upon the development of strategies to attack the tumour more effectively, but with less toxicity. Intrathecal chemotherapy, is an ideal but currently underused method of directly targeting residual tumour within the area of resection and the leptomeningeal disease commonly associated with this tumour.

METHOD

We describe the case of a 12 yr old child with metastatic medulloblastoma, who received intrathecal topotecan via a spinal catheter.

CONCLUSION

This method represents a simple, safe and effective method of delivering an even and widespread distribution of drug within the cerebrospinal fluid (CSF) of the neuroaxis. With new agents being identified and others in the early stages of development, intrathecal chemotherapy may emerge as an important therapeutic option to consider when faced with such challenging cases.

Tositumomab and Iodine I 131 Tositumomab for Recurrent Indolent and Transformed B-Cell Non-Hodgkin’s Lymphoma

Purpose

An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma.

Patients and Methods

A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 × 109/L). Forty of 41 patients received both infusions.

Results

Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient.

Conclusion

High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Asking questions can help: development and preliminary evaluation of a question prompt list for palliative care patients

Question prompt lists (QPLs) have been shown to be an inexpensive and effective communication tool for patients in oncology consultations. We aimed to develop and pilot a QPL for palliative care (PC) patients. In order to identify suitable questions for inclusion in the QPL, we conducted focus groups and individual interviews with 19 patients, 24 carers and 22 PC health professionals. A further 21 health professionals reviewed the draft document. The draft QPL was piloted in 23 patients. In total, 112 questions were identified and grouped into eight categories. All participants felt that the QPL, in booklet form, could be a useful tool. Out of 23 patients in the pilot study, 22 agreed that the QPL was helpful, contained useful questions, was easy to understand and would be useful in the future. State anxiety (STAI) decreased after receiving the booklet and seeing the doctor in 16 out of 19 patients (overall anxiety decreased by a median of 8, IQR 1-13). Participants in the pilot study endorsed the inclusion of end-of-life issues in the QPL, despite some reservations expressed about this by health professionals in the individual interviews. We have identified a specific QPL that might facilitate useful dialogue between PC patients and their doctor. The QPL has strong support from patients, their carers and relevant health professionals.

Saccharomyces cerevisiae protein Pci8p and human protein eIF3e/Int-6 interact with the eIF3 core complex by binding to cognate eIF3b subunits

Mammalian, plant, and Schizosaccharomyces pombe eukaryotic initiation factor-3 (eIF3) contains a protein homologous to the product of int-6 (eIF3e), a frequent integration site of mouse mammary tumor viruses. By contrast, Saccharomyces cerevisiae does not encode a protein closely related to eIF3e/Int-6. Here, we characterize a novel S. cerevisiae protein (Pci8p, Yil071cp) that contains a PCI (proteasome-COP9 signalosome-eIF3) domain conserved in eIF3e/Int-6. We show that both Pci8p and human eIF3e/Int-6 expressed in budding yeast interact with the yeast eIF3 complex in vivo and in vitro by binding to a discrete segment of its eIF3b subunit Prt1p and that human eIF3e/Int-6 interacts with the human eIF3b segment homologous to the Pci8p-binding site of yeast Prt1p. These results refine our understanding of subunit interactions in the eIF3 complex and suggest structural similarity between human eIF3e/Int-6 and yeast Pci8p. However, deletion of PCI8 had no discernible effect on cell growth or translation initiation as judged by polysome analysis, suggesting that Pci8p is not required for the essential function of eIF3 in translation initiation. Motivated by the involvement of Int-6 in transcriptional control, we investigated the effects of deleting PCI8 on the total mRNA expression profile by oligonucleotide microarray analysis and found reduced mRNA levels for a subset of heat shock proteins in the pci8Delta mutant. We discuss possible dual functions of Pci8p and Int-6 in transcriptional and translational control.

Fission yeast homolog of murine Int-6 protein, encoded by mouse mammary tumor virus integration site, is associated with the conserved core subunits of eukaryotic translation initiation factor 3

The murine int-6 locus, identified as a frequent integration site of mouse mammary tumor viruses, encodes the 48-kDa eIF3e subunit of translation initiation factor eIF3. Previous studies indicated that the catalytically active core of budding yeast eIF3 consists of five subunits, all conserved in eukaryotes, but does not contain a protein closely related to eIF3e/Int-6. Whereas the budding yeast genome does not encode a protein closely related to murine Int-6, fission yeast does encode an Int-6 ortholog, designated here Int6. We found that fission yeast Int6/eIF3e is a cytoplasmic protein associated with 40 S ribosomes. FLAG epitope-tagged Tif35, a putative core eIF3g subunit, copurified with Int6 and all five orthologs of core eIF3 subunits. An int6 deletion (int6Delta) mutant was viable but grew slowly in minimal medium. This slow growth phenotype was accompanied by a reduction in the amount of polyribosomes engaged in translation and was complemented by expression of human Int-6 protein. These findings support the idea that human and Schizosaccharomyces pombe Int-6 homologs are involved in translation. Interestingly, haploid int6Delta cells showed unequal nuclear partitioning, possibly because of a defect in tubulin function, and diploid int6Delta cells formed abnormal spores. We propose that Int6 is not an essential subunit of eIF3 but might be involved in regulating the activity of eIF3 for translation of specific mRNAs in S. pombe.

The reduction of itch during burn wound healing

The purpose of this study was to find a method to reduce the itch experienced by patients who have sustained burn injuries, by using and comparing the effectiveness of 2 shower and bath oils. One product contained liquid paraffin with 5% colloidal oatmeal and the other contained liquid paraffin. The study was carried out in the Adult Burns Unit, Royal Brisbane Hospital (RBH), Brisbane. It was conducted during a 10-month period from July 1998 until April 1999. Thirty-five acute burns patients participated in an assessor-blind clinical trial. Patients were asked twice daily to rate their discomfort from itch and pain. The amount of antihistamine requested by each patient was totalled daily. Analysis of data supplied by patients showed that the group using the product with colloidal oatmeal reported significantly less itch and requested significantly less antihistamine than those using the oil containing liquid paraffin.

A multifactor complex of eukaryotic initiation factors, eIF1, eIF2, eIF3, eIF5, and initiator tRNA(Met) is an important translation initiation intermediate in vivo

Translation initiation factor 2 (eIF2) bound to GTP transfers the initiator methionyl tRNA to the 40S ribosomal subunit. The eIF5 stimulates GTP hydrolysis by the eIF2/GTP/Met-tRNA(i)(Met) ternary complex on base-pairing between Met-tRNA(i)(Met) and the start codon. The eIF2, eIF5, and eIF1 all have been implicated in stringent selection of AUG as the start codon. The eIF3 binds to the 40S ribosome and promotes recruitment of the ternary complex; however, physical contact between eIF3 and eIF2 has not been observed. We show that yeast eIF5 can bridge interaction in vitro between eIF3 and eIF2 by binding simultaneously to the amino terminus of eIF3 subunit NIP1 and the amino-terminal half of eIF2beta, dependent on a conserved bipartite motif in the carboxyl terminus of eIF5. Additionally, the amino terminus of NIP1 can bind concurrently to eIF5 and eIF1. These findings suggest the occurrence of an eIF3/eIF1/eIF5/eIF2 multifactor complex, which was observed in cell extracts free of 40S ribosomes and found to contain stoichiometric amounts of tRNA(i)(Met). The multifactor complex was disrupted by the tif5-7A mutation in the bipartite motif of eIF5. Importantly, the tif5-7A mutant is temperature sensitive and displayed a substantial reduction in translation initiation at the restrictive temperature. We propose that the multifactor complex is an important intermediate in translation initiation in vivo.

Radiology case of the month. Incidental discovery on mammography done for a palpable breast mass. Granular cell tumor

A 32-two-year-old woman complains of a palpable lump in her left breast. Her past medical and family history is non-contributory. There was no palpable lump on clinical breast examination. A mammogram was performed.

Vaccination of mice with DNA encoding a large fragment of botulinum neurotoxin serotype A

The potential utility of using DNA vaccination to protect mice from the microbial neurotoxin, botulinum toxin type A, was evaluated. A synthetically derived gene encoding a carboxyl-terminal 50 kDa fragment of the toxin was placed in two sites in the DNA inoculation vehicle pCMVint-BL (Vical), one predicted to lead to MHC I processing (pJT-1 construct) and the other to direct MHC II processing (pJT-2 construct). Mice were then inoculated at 3 week intervals with these two constructs and with the vehicle alone and evaluated for protection from botulinum toxin by i.p. challenges with various toxin doses. Protection was observed at about week 10-11 from toxin doses of 25-100 LD(50). Only animals inoculated with pJT-2 exhibited protection. In dose-response experiments, 50 micrograms of DNA was the minimal dose required to elicit a protective response against serotype A, while protection against serotypes B or E was not obtained. With standard ELISA testing, a relationship was observed between the level of protection and the level of ELISA reactive antibody. Our results support the concept that DNA vaccination is a viable methodology to use in cases where protection from toxins is the goal.

Sequence and expression of the kettin gene in Drosophila melanogaster and Caenorhabditis elegans

Kettin is a large modular protein associated with thin filaments in the Z-disc region of insect muscles. The sequence of a 21.3 kb contig of the Drosophila gene has been determined. The corresponding protein sequence has 35 immunoglobulin-like (Ig) domains which are separated by shorter linker sequences, except near the N and C termini of the molecule where linker sequences are short or missing. This confirms a model in which each Ig domain binds to an actin protomer. The Drosophila kettin gene is at 62C 1-3 on the third chromosome. Two P-element insertions, l(3)j1D7 and l(3)rL182 are in the kettin gene, and complementation tests showed that existing l(3)dre8 mutations are in the same gene. The RNA was detected in wild-type Drosophila embryos at stage 11, first in the gut invagination region of the mesoderm, and by stage 13 in both visceral and somatic mesoderm. Somatic mesoderm expression became segmental at stage 13. RNA expression was greatly reduced in embryos of P-element homozygotes but normal in heterozygotes. The structure of the flight muscle in all the heterozygous mutants was normal, including the myofibril-cuticle connections, and they were able to fly. Kettin sequence homologous to the Drosophila protein, was identified in the Caenorhabditis elegans genome database. The RNA was detected in pharyngeal, body wall and anal depressor muscles of larvae and adult worms, as well as in the male gonad. Antibody to insect kettin labelled the pharyngeal, body wall, anal depressor and proximal gonadal muscles in adult worms. Body wall muscles were labelled in an obliquely striated pattern consistent with the Z-disc localisation in insect muscle. The relationship of kettin to D-titin, which has been assigned to the same chromosomal locus in Drosophila, is discussed.

Drosophila ACT88F indirect flight muscle-specific actin is not N-terminally acetylated: a mutation in N-terminal processing affects actin function

Many eukaryotic proteins are co and post-translationally modified at their N termini by removal of one or two amino acid residues and N(alpha)-acetylation. Actins show two different forms of N-terminal processing dependent on their N-terminal sequence. In class II actins, which include muscle actins, the common primary sequence of Met-Cys-Asp-actin is processed to acetyl-Asp-actin. The functional significance of this in vivo is unknown. We have studied the indirect flight muscle-specific actin, ACT88F, of Drosophila melanogaster. Our results show that ACT88F is N-terminally processed in vivo as a class II actin by removal of the first two amino acid residues (Met and Cys), but that uniquely the N terminus is not acetylated. In addition we show that ACT88F is methylated, probably at His73. Flies carrying the mod(-) mutation fail to complete post-translational processing of ACT88F. We propose that the mod gene product is normally responsible for removing N-acetyl-cysteine from actin. The biological significance of this process is demonstrated by observations that retention of the N-acetyl-cysteine in ACT88F affects the flight muscle function of mod(-) flies. This suggests that the extreme N terminus affects actomyosin interactions in vivo, a proposal we have examined by in vitro motility assays of ACT88F F-actin from mod(-) flies. The mod(-) actin only moves in the presence of methylcellulose, a viscosity-enhancing agent, where it moves at velocities slightly, but significantly, reduced compared to wild-type. These data confirm that N-acetyl-cysteine at the N terminus affects actomyosin interactions, probably by reducing formation of the initial actomyosin collision complex, a process known to involve the actin N terminus.

Changing trends in the laboratory diagnosis of gastroenteritic infections

The micro-organisms responsible for causing gastroenteritis have changed over the last few decades. This article chronicles those changes and describes the laboratory tests devised to improve diagnosis.

Promoting evidence-based practice: managing change in the assessment of pressure damage risk

AIMS

This study set out to facilitate the development of evidence-based practice in the assessment of pressure damage risk to patients within a large acute hospital.

BACKGROUND

The importance of nursing practice being based on the best available evidence is emphasized in recent health policy. Meeting this objective is not easy as both individual and organizational factors create barriers to the implementation of research findings and the achievement of change.

METHODS

The study was based on an action research model. It comprised three stages: a review of the research evidence; a survey of qualified nurses' knowledge of risk assessment of pressure damage and an audit of record keeping, and a multifaceted approach to achieving change in which researchers, managers, practitioners and clinical nurse specialists worked together collaboratively.

FINDINGS

The findings from the survey and audit indicated a shortfall in nurses' knowledge of risk assessment of pressure damage and in their record keeping. The researchers, with the help of the clinical nurse specialist, built upon these findings by assisting practitioners and managers to take ownership of the need to base practice on the appropriate evidence.

CONCLUSIONS

Achieving evidence-based practice is a complex undertaking that requires the development of an evaluative culture and a commitment by practitioners and managers to change practice. Researchers can play a valuable role in facilitating this process.

Familial high myopia: evidence of an autosomal dominant mode of inheritance and genetic heterogeneity

High myopia, defined as a refractive error inferior to -6 diopters, often appears as a familial disease. In order to precise its genetic background, we performed a segregation analysis on 32 French families (320 subjects including 120 individuals with clinical data) containing at least one high myopic person in their genealogy. Under the assumption of a two-alleles single gene model, the autosomal dominant transmission mode showed a much greater likelihood than the autosomal recessive mode, which therefore was rejected. From the segregation model obtained, a two-point linkage analysis was made on 18 families (107 subjects), among the 32 used for the segregation analysis. Different candidate loci were tested: collagen genes including Stickler syndrome types 1 and 2, proteoglycan genes, Marfan 1 syndrome and a Marfan like disorder localised in 3p24.2-p25. No evidence of linkage was found with any of the studied markers. In addition, the absence of linkage with chromosome 18p11.31 markers, a locus linked to familial high myopia in 6 North American families and 1 family of Chinese descent, demonstrated the genetic heterogeneity of the disease.

Let there be life: an approach to worship with Alzheimer's patients and their families

Describes a novel approach to providing a meaningful worship service for Alzheimer's patients in which greater stress is placed upon familiar scripture, music, prayers, and other right-brain functions, rather than on sermon or homily.

Association of kettin with actin in the Z-disc of insect flight muscle

The Z-discs of insect muscle contain kettin, a modular protein of 500-700 kDa. The Drosophila protein is made up of a chain of immunoglobulin (Ig) domains separated by linker sequences. Kettin differs from other modular muscle proteins of the Ig superfamily in binding to thin filaments rather than thick filaments. Kettin isolated from Lethocerus (waterbug) muscle is an elongated molecule 180 nm long, which binds to F-actin with high affinity (Kd=1.2 nM) and a stoichiometry of one Ig domain per actin protomer. Competition between kettin and tropomyosin for binding to actin excludes tropomyosin from the Z-disc. In contrast, kettin and alpha-actinin bind simultaneously to actin, which would reinforce the Z-disc lattice. In vitro, kettin promotes the antiparallel association of actin filaments, and a similar process may occur in the developing sarcomere: actin filaments interdigitate in an antiparallel fashion in the Z-disc with the N terminus of kettin within the Z-disc, and the C terminus some way outside. We propose a model for the association of kettin with actin in which the molecule follows the genetic helix of actin and Ig domains, separated by linker sequences, bind to each actin protomer.

HLA-A, -B, -C polymorphism in a UK Ashkenazi Jewish potential bone marrow donor population

To further our knowledge of HLA polymorphism in different ethnic populations and to increase the number of full HLA class I typed potential bone marrow donors on the Anthony Nolan Bone Marrow Trust register, HLA-A, -B and -C polymorphism was characterised in 412 Ashkenazi Jewish potential donors. Serological typings and limited molecular analysis was performed for HLA-A and -B, and molecular typings were performed for HLA-C. Gene and haplotype frequencies were calculated using the maximum likelihood method and compared with UK Caucasoid and other Jewish populations. While the specificities identified were in general overlapping with the UK Caucasoid data, a difference in the frequencies of individual specificities was observed. For example, HLA-B62, a common serotype found in the UK Caucasoid population, is almost absent in the Ashkenazim. HLA-A, -C, -B haplotype frequencies also differ between the two populations with A26-Cw*1203-B38 and A24-Cw*04-B35 significant in the Ashkenazim, whilst A1-Cw*07-B8, a common Caucasoid haplotype, was found to be less frequent. Overall the results for the UK Ashkenazi population were most similar to previous reports on Polish/Russian Jews.