The many forms of a pleomorphic bacterial pathogen-the developmental network of Legionella pneumophila

Legionella pneumophila is a natural intracellular bacterial parasite of free-living freshwater protozoa and an accidental human pathogen that causes Legionnaires' disease. L. pneumophila differentiates, and does it in style. Recent experimental data on L. pneumophila's differentiation point at the existence of a complex network that involves many developmental forms. We intend readers to: (i) understand the biological relevance of L. pneumophila's forms found in freshwater and their potential to transmit Legionnaires' disease, and (ii) learn that the common depiction of L. pneumophila's differentiation as a biphasic developmental cycle that alternates between a replicative and a transmissive form is but an oversimplification of the actual process. Our specific objectives are to provide updates on the molecular factors that regulate L. pneumophila's differentiation (Section The Differentiation Process and Its Regulation), and describe the developmental network of L. pneumophila (Section Dissecting Lp's Developmental Network), which for clarity's sake we have dissected into five separate developmental cycles. Finally, since each developmental form seems to contribute differently to the human pathogenic process and the transmission of Legionnaires' disease, readers are presented with a challenge to develop novel methods to detect the various L. pneumophila forms present in water (Section Practical Implications), as a means to improve our assessment of risk and more effectively prevent legionellosis outbreaks.

An investigation into the persistence of textile fibres on buried carcasses

A significant amount of research has been carried out on fibres to aid the forensic scientist in determining the significance of these when found on a victim or suspect. This work has focused on open-air environments, and as such no research has been undertaken to examine the persistence of fibres on bodies in the burial environment. Wool and cotton fibres, known to fluoresce under ultraviolet (UV) light, were transferred onto the skin of four porcine (Sus scrofa) carcasses (two carcasses per fibre type). The number of fibres transferred was recorded from images taken under UV light. The remains were subsequently placed in four burial sites and left interred for 14 days. After this period the carcasses were excavated and lightly brushed down to remove the soil layer that had adhered to the skin. Once again photography under UV light was used to record the number of fibres which persisted on the skin. Results showed that after 14 days, wool and cotton fibres remain on the surface of the buried carcasses. In no circumstance was there a total loss of fibres suggesting that in such scenarios, the likelihood of finding fibres is high but the initial number of fibres transferred would be strongly diminished. This has important implications for both the excavation protocol for buried remains and the subsequent analysis for physical evidence.

Congenital cytomegalovirus infection is associated with high maternal socio-economic status and corresponding low maternal cytomegalovirus seropositivity

AIMS

Human cytomegalovirus (CMV) is the leading infectious cause of congenital infection in developed countries. Globally, CMV seropositivity has been associated with low socio-economic status (SES); however, Australian data are lacking. Therefore, we examined the association between SES and CMV seroprevalence in children and pregnant women.

METHODS

Three groups were examined: 1, a prospective cohort of Australian children aged 0-15 years (n = 220); 2, a clinic-based sample of pregnant women (n = 778); and 3, a case series of infants and children (n = 219) with symptomatic congenital CMV infection. SES was determined using a postcode-based score from the Australian Bureau of Statistics.Group 1 was recruited from endocrinology clinics and follow-up at Prince of Wales Hospital and Children's Hospital at Westmead. Group 2 was recruited at the Royal Hospital for Women. Congenitally infected infants were identified through the Australian Paediatric Surveillance Unit.

RESULTS

CMV seroprevalence among all children was 20% (95% confidence interval (CI) 15-25%), and there was no association with SES (P = 0.58). Seroprevalence among pregnant women was 57% (53-60%), and higher rates of CMV seropositivity were associated with lower SES (P < 0.001). More congenital CMV cases were reported in the highest socio-economic groups (55%) than the lowest (9%) (P < 0.001).

CONCLUSIONS

A marked socio-economic gradient in CMV seroprevalence is evident in Australian pregnant women and cases of congenital CMV but not in unselected Australian children. These findings highlight the importance of a community-wide approach to CMV awareness and the potential for hygienic measures to reduce the burden of congenital CMV in Australia.

The degradation of p53 and its major E3 ligase Mdm2 is differentially dependent on the proteasomal ubiquitin receptor S5a

p53 and its major E3 ligase Mdm2 are both ubiquitinated and targeted to the proteasome for degradation. Despite the importance of this in regulating the p53 pathway, little is known about the mechanisms of proteasomal recognition of ubiquitinated p53 and Mdm2. In this study, we show that knockdown of the proteasomal ubiquitin receptor S5a/PSMD4/Rpn10 inhibits p53 protein degradation and results in the accumulation of ubiquitinated p53. Overexpression of a dominant-negative deletion of S5a lacking its ubiquitin-interacting motifs (UIM)s, but which can be incorporated into the proteasome, also causes the stabilization of p53. Furthermore, small-interferring RNA (siRNA) rescue experiments confirm that the UIMs of S5a are required for the maintenance of low p53 levels. These observations indicate that S5a participates in the recognition of ubiquitinated p53 by the proteasome. In contrast, targeting S5a has no effect on the rate of degradation of Mdm2, indicating that proteasomal recognition of Mdm2 can be mediated by an S5a-independent pathway. S5a knockdown results in an increase in the transcriptional activity of p53. The selective stabilization of p53 and not Mdm2 provides a mechanism for p53 activation. Depletion of S5a causes a p53-dependent decrease in cell proliferation, demonstrating that p53 can have a dominant role in the response to targeting S5a. This study provides evidence for alternative pathways of proteasomal recognition of p53 and Mdm2. Differences in recognition by the proteasome could provide a means to modulate the relative stability of p53 and Mdm2 in response to cellular signals. In addition, they could be exploited for p53-activating therapies. This work shows that the degradation of proteins by the proteasome can be selectively dependent on S5a in human cells, and that this selectivity can extend to an E3 ubiquitin ligase and its substrate.

Clinical Practice Guideline Development Manual, Third Edition: a quality-driven approach for translating evidence into action

BACKGROUND

Guidelines translate best evidence into best practice. A well-crafted guideline promotes quality by reducing health care variations, improving diagnostic accuracy, promoting effective therapy, and discouraging ineffective-or potentially harmful-interventions. Despite a plethora of published guidelines, methodology is often poorly defined and varies greatly within and among organizations.

PURPOSE

The third edition of this manual describes the principles and practices used successfully by the American Academy of Otolaryngology--Head and Neck Surgery Foundation to produce quality-driven, evidence-based guidelines using efficient and transparent methodology for actionable recommendations with multidisciplinary applicability. The development process emphasizes a logical sequence of key action statements supported by amplifying text, action statement profiles, and recommendation grades linking action to evidence. New material in this edition includes standards for trustworthy guidelines, updated classification of evidence levels, increased patient and public involvement, assessing confidence in the evidence, documenting differences of opinion, expanded discussion of conflict of interest, and use of computerized decision support for crafting actionable recommendations.

CONCLUSION

As clinical practice guidelines become more prominent as a key metric of quality health care, organizations must develop efficient production strategies that balance rigor and pragmatism. Equally important, clinicians must become savvy in understanding what guidelines are--and are not--and how they are best used to improve care. The information in this manual should help clinicians and organizations achieve these goals.

Arrhythmias in Fabry cardiomyopathy

BACKGROUND

Prior studies suggest that the incidence of ventricular arrhythmias is high in patients with Fabry cardiomyopathy. This study evaluated the incidence of significant arrhythmias in a series of patients with Fabry cardiomyopathy.

HYPOTHESIS

Arrhythmias are important causes of morbidity and mortality in Fabry Cardiomyopathy.

METHODS

This study was a retrospective chart review of 19 patients with known Fabry cardiomyopathy. Device interrogation reports were reviewed for those who had implantable devices. Electrocardiogram, Holter monitor, and event monitors were reviewed in those who did not have implantable devices.

RESULTS

Eighteen of nineteen patients were on enzyme replacement therapy (ERT). Nine (47%) out of 19 patients had implantable devices. Implant indications included symptomatic bradycardia, nonsustained ventricular tachycardia, conduction abnormalities, palpitations, and syncope. Mean follow-up in the patients with devices was 50 ± 23 months. Two patients received implantable cardioverter-defibrillator (ICD) shocks, 1 of which was inappropriate for atrial fibrillation. Patients were paced in the atrium 71% ± 37% of the time and paced in the ventricle 49% ± 52% of the time. Four patients with devices were paced more than 95% of the time. Patients with an ICD had lower heart rates prior to ICD implant than the group that did not have devices (60 ± 10 vs 78 ± 16, P = 0.03). Of the patients without devices, only 1 had sudden cardiac death. Patients with implanted devices had higher left ventricular (LV) mass indices compared to patients without implanted devices (136 ± 40 g/m(2) vs 93 ± 19 g/m(2), P = 0.008).

CONCLUSIONS

Significant ventricular arrhythmias are uncommon in patients with Fabry cardiomyopathy on ERT, but utilization of pacing is high. Sudden cardiac death in Fabry cardiomyopathy may be related to bradycardia.

Laboratory diagnosis, molecular characteristics, epidemiological and clinical features of an outbreak of measles in a low incidence population in Australia

BACKGROUND

Prompt and accurate laboratory diagnosis of measles is essential for case detection, outbreak management and ongoing surveillance in low incidence countries. Several disease markers are employed for diagnosis and are important to determine epidemiological and molecular characteristics for future control measures.

OBJECTIVES

To report different disease markers, genotypes and epidemiology of a measles outbreak in Australia, a low incidence country.

STUDY DESIGN

A retrospective descriptive study of the clinical and epidemiological features and laboratory diagnosis in 16 confirmed measles cases using measles serum IgM/IgG, antigen detection (IFA), viral RNA detection by real-time PCR and genotyping results for respiratory and urine specimens processed in one reference laboratory.

RESULTS

Of the 16 confirmed measles cases, 11 were young adults aged between 20-35 years and 15 were not age-appropriately vaccinated. The most common genotype detected was D9 (11/16), followed by D4 (1/16) and D8 (1/16). Two imported cases were from the Philippines (D4) and Italy (D9). Of six disease markers, respiratory swab PCR and serum IgM gave the highest percentage (100%) of positive samples for confirmed cases followed by urine PCR (90.9%), serum PCR (66.6%), urine IFA (54.5%) and respiratory IFA (46.2%).

CONCLUSIONS

Measles should be considered in the differential diagnosis of a presentation with fever and rash, even in countries in the elimination phase of measles control. Genotyping is a powerful molecular-epidemiological tool to assist low incidence countries towards eradication goals. Improving vaccination coverage remains essential, particularly in young adults and travellers.

Perioperative care: a survey of New Zealand and Australian colorectal surgeons

AIM

Recent surveys in Europe and North America have demonstrated significant challenges in the implementation of evidence-based surgical practice.

METHOD

A survey of New Zealand and Australian colorectal surgeons was conducted to help understand current practice and perceived barriers to interventions in this region. Questions were based around elective colorectal resection care.

RESULTS

There were 152 eligible participants identified. Over a 60-day period, 82 (54%) surgeons responded but only 76 (50%) of the questionnaires were complete; they were used for data analysis. The majority of surgeons indicated a preference for laparoscopic techniques. Barriers to laparoscopy include lack of operating time, lack of adequate training and institutional pressures. Only 28 (37%) indicated that they cared for patients in a formalized enhanced recovery programme (ERAS). Barriers to implementing ERAS included lack of support from institutions and other specialities. Routine oral 'mechanical' bowel preparation for colon and rectal resection was preferred by 28% and 63%, respectively. Drainage after routine colon and rectal resection was not used by 62 (83%) and 39 (53%). Prophylactic nasogastric intubation afterwards was not used by 66 (87%) responders. The preferred mode of analgesia was patient-controlled opioid analgesia (PCA) for 52%. A 'restrictive' intravenous fluid therapy was preferred by 34 (49%) while 33 (48%) preferred no fluid restriction. A prolonged 'nil by mouth' status was preferred by 28%.

CONCLUSION

There appears to be a high rate of evidence in agreement with some interventions but not others. The systemic barriers to implementing evidence-based perioperative care need attention.

Clinical practice guideline: Polysomnography for sleep-disordered breathing prior to tonsillectomy in children

OBJECTIVE

This guideline provides otolaryngologists with evidence-based recommendations for using polysomnography in assessing children, aged 2 to 18 years, with sleep-disordered breathing and are candidates for tonsillectomy, with or without adenoidectomy. Polysomnography is the electrographic recording of simultaneous physiologic variables during sleep and is currently considered the gold standard for objectively assessing sleep disorders.

PURPOSE

There is no current consensus or guideline on when children 2 to 18 years of age, who are candidates for tonsillectomy, are recommended to have polysomnography. The primary purpose of this guideline is to improve referral patterns for polysomnography among these patients. In creating this guideline, the American Academy of Otolaryngology--Head and Neck Surgery Foundation selected a panel representing the fields of anesthesiology, pulmonology medicine, otolaryngology-head and neck surgery, pediatrics, and sleep medicine.

RESULTS

The committee made the following recommendations: (1) before determining the need for tonsillectomy, the clinician should refer children with sleep-disordered breathing for polysomnography if they exhibit certain complex medical conditions such as obesity, Down syndrome, craniofacial abnormalities, neuromuscular disorders, sickle cell disease, or mucopolysaccharidoses. (2) The clinician should advocate for polysomnography prior to tonsillectomy for sleep-disordered breathing in children without any of the comorbidities listed in statement 1 for whom the need for surgery is uncertain or when there is discordance between tonsillar size on physical examination and the reported severity of sleep-disordered breathing. (3) Clinicians should communicate polysomnography results to the anesthesiologist prior to the induction of anesthesia for tonsillectomy in a child with sleep-disordered breathing. (4) Clinicians should admit children with obstructive sleep apnea documented on polysomnography for inpatient, overnight monitoring after tonsillectomy if they are younger than age 3 or have severe obstructive sleep apnea (apnea-hypopnea index of 10 or more obstructive events/hour, oxygen saturation nadir less than 80%, or both). (5) In children for whom polysomnography is indicated to assess sleep-disordered breathing prior to tonsillectomy, clinicians should obtain laboratory-based polysomnography, when available.

Infectious disease screening of blood specimens collected post-mortem provides comparable results to pre-mortem specimens

Serology assays for standard screening are optimised for use with sera collected from living adults and children. Because of potential changes in the vascular compartments after death, methods used for screening sera from cadaveric organ donors need to be validated before testing these specimens. Serum was separated from blood collected from cadaveric donors within 24 h of death and biochemical parameters measured to detect dilution of protein and haemolysis. In order to demonstrate if any inhibitors that might interfere with the assays were present, pre and post-mortem specimens were spiked with aliquots of human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), human T-cell Lymphotropic Virus (HTLV) and T. pallidum-positive sera. Comparison of serum from living subjects with serum obtained post-mortem showed that while the concentration of total protein decreased, concentrations of albumin, immunoglobulin G (IgG) and immunoglobulin M (IgM) remained unchanged. The degree of haemolysis, as measured by free haemoglobin, was within the limits accepted for the Architect analyser. Spiking of pre- and post-mortem specimens with aliquots of HIV, HCV, HBV, HTLV and T. pallidum-positive sera showed no statistical difference in the signal between pre-mortem and post-mortem results when tested on the Abbott Architect analyser. Positive results were obtained in each of a further nine subjects who had tested positive for HIV (n=1), HCV (n=8), HBV (n=1) on pre-mortem serological testing. These findings suggest that the sensitivity of the Abbott Architect serological screening tests is not significantly affected in specimens collected within 24 h of the cessation of life.

Detection of human cytomegalovirus IgG antibody using automated immunoassay with recombinant antigens gives uniform results to established assays using whole virus antigens

AIM

Serological testing for human cytomegalovirus (CMV) immunoglobulin G (IgG) continues to play a major role in the evaluation of tissue and organ transplant donors and recipients, screening blood donors and in estimating the risk of infection in pregnant women. In this study we evaluated the performance and technical characteristics of two semi-automated commercial CMV IgG immunoassays.

METHODS

One hundred consecutive sera submitted to a referral serology laboratory for CMV IgG antibody testing were assayed using two automated CMV IgG immunoassays: the Architect (Abbott Diagnostics) and Elecsys (Roche Diagnostics) immunoassays. Because this patient population has a high rate (∼87%) of seropostivity, we took a further 50 sera that were CMV IgG negative on Architect and tested on the Elecsys assay, in order to assess the specificity of the assays.

RESULTS

The assays showed an excellent qualitative agreement with two (2%) discrepant results in the 100 patients tested initially, with all of the 50 additional sera negative on Architect also negative on the Elecsys. However, there was no correlation between the optical density of results generated by the instruments for the set of samples.

CONCLUSION

Both Elecsys and Architect immunoassays are convenient for detection of CMV IgG antibody, with near identical qualitative results.

Outcomes of an interdisciplinary rehabilitation programme for the management of chronic low back pain

BACKGROUND AND CONTEXT: The health and economic costs associated with chronic low back pain (CLBP) have increased substantially over the past few decades. Despite extensive research, a consistently valid, reliable and effective diagnostic and treatment regime for CLBP is yet to be determined. ASSESSMENT OF PROBLEM: This paper presents an established interdisciplinary rehabilitation model for CLBP initially developed by the Canadian Back Institute. An audit describes the symptomatic, functional and vocational outcomes achieved for patients who attended the programme over three years throughout a national network of primary health care facilities in New Zealand. RESULTS: Over a three-year period, 899 patients with CLBP completed their rehabilitation programme at one of eight affiliated clinics. Of the 899 patients discharged, 780 (86.8%) reported that their back pain had gone or reduced at the end of their rehabilitation. There was a statistically significant, and clinically relevant, improvement in both average pain and subjective functional scores from baseline assessment levels to discharge and follow-up scores (p<0.001). STRATEGIES FOR IMPROVEMENT: Previous studies have shown that functional rehabilitation can improve outcomes in individuals with CLBP. This audit provides further support for the development of interdisciplinary functional rehabilitation programmes to help manage CLBP within the community. LESSONS: The routine measurement of symptomatic, functional and vocational outcomes throughout the rehabilitation process can assist in quantifying the effect of treatment and providing evidence of value for patients, stakeholders and funding groups. KEYWORDS: Low back pain; outcomes; rehabilitation

Development of occult hepatitis B viral infection in pregnancy: implications for antenatal screening in women from endemic areas

Occult hepatitis B virus (HBV) infection, manifest clinically by the presence of HBV deoxyribonucleic acid (HBV DNA) in peripheral blood in individuals who test negative for the HBV surface antigen (HBsAg), may occur in various clinical contexts, including under the influence of pharmacological immunosuppression in patients from areas endemic for HBV and, hence, at risk of previous exposure. Pregnancy is a condition associated with immune suppression, but whether virus-specific immunity may be suppressed to an extent sufficient to allow occult HBV infection to develop is currently unknown. This is potentially relevant not only to the mother's health but also because vertical transmission has been reported in the occult HBV infection setting. We report a 30-year-old woman from a country endemic for HBV who, prior to pregnancy, was persistently HBsAg-negative with undetectable HBV DNA in peripheral blood, in whom HBV DNA became increasingly detectable during pregnancy, peaking in the third trimester, before returning to undetectable levels postpartum. HBsAg remained negative and liver function tests were normal throughout. Immunoglobulin M hepatitis B core antibody, a marker of the possibility of acquisition of a new HBV infection, was also negative. The baby received immunization against HBV infection from birth and has remained HBV negative at six months. This report documents for the first time that occult HBV infection may develop during pregnancy. Further data are required regarding the prevalence of this phenomenon, predisposing factors, impact on maternal health and risk of vertical transmission so that implications for current antenatal screening strategies that do not include measurement of HBV DNA in peripheral blood can be properly determined.

Phase III study of sustained release granisetron (APF530) compared to palonosetron for the prevention of chemotherapy-induced nausea and vomiting (CINV)

9627

Background: APF530 is a polymeric formulation of granisetron providing sustained drug release over 5 days. Two doses (5 and 10 mg) of subcutaneous APF530 were evaluated in comparison to 0.25 mg intravenous palonosetron. Efficacy was evaluated in acute (0–24 hrs) and delayed (24–120 hrs) CINV among patients receiving moderate (MEC) or highly (HEC) emetogenic chemotherapy. Methods: Randomized, blinded patients (n=1,395) were stratified into MEC or HEC according to Hesketh et al 1999, and assigned to receive either dose of APF530 or palonosetron. Dexamethasone use was standardized based on the emetogenic strata. Patient diaries recorded emetic episodes, nausea and rescue medications over a 5-day period. Primary endpoint was Complete Response (CR), defined as no emetic episodes and no rescue medication. Non-inferiority to palonosetron was declared if the lower bound of the CI for the difference was above -15%. Results: APF530 was well tolerated. Adverse events were consistent with those previously reported for granisetron. For APF530 Tmax was observed about 24 hrs with sustained levels over 120 hrs. For MEC acute phase CR rates of 74.8% (n=214), 76.9% (n=212) and 75.0% (n=208) were observed for 5 mg, 10 mg APF530 and palonosetron, respectively. Delayed phase CR rates of 51.4%, 59.0% and 57.7% were observed for 5 mg, 10 mg APF530 and palonosetron, respectively. For HEC acute phase CR rates of 77.7% (n=229), 81.3% (n=240) and 80.7% (n=238) were observed for 5 mg, 10 mg APF530 and palonosetron, respectively. Delayed phase CR rates of 64.6%, 68.3% and 66.4% were observed for 5 mg, 10 mg APF530 and palonosetron, respectively. Efficacy was maintained with APF530 over multiple cycles (up to 4). Conclusions: Both doses of APF530 were non-inferior to palonosetron with respect to CR during the acute phase following MEC and HEC. Only the higher dose of APF530 (10 mg granisetron) was non-inferior to palonosetron during the delayed phase of MEC. Both doses of APF530 were comparable to the CR rates of palonosetron during the delayed phase of HEC.

[Table: see text]

Evaluation of two human plasma pools as candidate international standard preparations for syphilitic antibodies

A collaborative study was designed to asses two freeze-dried human plasma preparations containing anti-Treponema pallidum antibodies, 05/132 and 05/122, for their suitability as international reference reagents for syphilis serology. Both preparations are intended as replacements of the first international standard (IS) for syphilitic serum antibodies (HS). Samples were tested by eight laboratories using the T. pallidum passive particle agglutination assay (TPPA), the venereal disease research laboratory test (VDRL) and the rapid plasma reagin test (RPR). In addition a range of immunoassays was also used. The outcome of the collaborative study revealed that candidate standard 05/132 contains T. pallidum-specific IgG and IgM and is reactive in VDRL or RPR, and that 05/122 contains T. pallidum-specific IgG but is not reactive in either the VDRL or RPR test. Both 05/132 and 05/122 are reactive in the TPPA. On the basis of these results the Expert Committee on Biological Standardization of the World Health Organization designated 05/132 as the 1st IS for human syphilitic plasma IgG and IgM with a unitage of 3 IU per ampoule relative to HS and 05/122 as the 1st IS for human syphilitic plasma IgG with a unitage of 300 mIU per ampoule relative to 05/132.