New St. Jude Medical Portico™ transcatheter aortic valve: features and early results

Patients with symptomatic aortic valve disease who are inoperable or have high surgery-related risks may be treated with transcatheter aortic valve implantation devices. With this method increasingly applied, device innovations are aimed at achieving improved procedural results and therapeutic outcome. This paper describes the innovations implemented in the St. Jude Medical Portico™ system for transcatheter aortic valve implantation, the application of this system and initial clinical experience.

Epigenetic regulation of the innate immune response to LPS in bovine peripheral blood mononuclear cells (PBMC)

Epigenetic regulation of gene expression could help explain variation in responses to infection and differences in disease susceptibility in cattle. The aim of this study was to examine epigenetic mechanisms in the regulation of LPS-induced innate immune gene expression in peripheral blood mononuclear cells (PBMCs) from five healthy calves. Firstly, epigenetic enzyme gene expression (histone deacetylase (HDAC) and DNA methyltransferase (DNMT)) was measured after LPS stimulation. Secondly, the effect of the histone deacetylase inhibitor Trichostatin A (TSA) on histone H3 acetylation and on innate immune gene expression was also measured. Results showed differential expression of HDAC6, HDAC7 and DNMT3A genes in response to LPS in cells from all animals, while TSA significantly inhibited pro-inflammatory cytokine (TNF, IL2 and IFNG) expression (P<0.05), presumably by histone acetylation. These results suggest an important role for the HDAC family of enzymes in the regulation of bovine innate immune gene expression.

What hope for the future? GNAQ and uveal melanoma

Uveal melanomas (UM) are aggressive ocular tumours that spread to the liver. They are characterised by alterations of chromosome 3 and 8, which are highly predictive of a poor prognosis. Unfortunately, being able to identify those patients with aggressive disease has not, as yet, translated into improved survival. Recently, mutations of guanine nucleotide-binding protein G(q) subunit alpha (GNAQ, or G-alpha-q), which effectively turn it into a dominantly acting oncogene, have been identified in approximately half of UM. These mutations are specific to UM and other non-cutaneous melanomas, and are not found in normal tissues, thus making them potential therapeutic targets. Here, the authors review the background to GNAQ in UM and explore what makes it such an interesting target for the future treatment of patients.

Targeted prostate cancer screening in men with mutations in BRCA1 and BRCA2 detects aggressive prostate cancer: preliminary analysis of the results of the IMPACT study

OBJECTIVE

To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported.

PATIENTS AND METHODS

Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation.

RESULTS

In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant.

CONCLUSIONS

The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.

Prostate cancer in male BRCA1 and BRCA2 mutation carriers has a more aggressive phenotype

There is a high and rising prevalence of prostate cancer (PRCA) within the male population of the United Kingdom. Although the relative risk of PRCA is higher in male BRCA2 and BRCA1 mutation carriers, the histological characteristics of this malignancy in these groups have not been clearly defined. We present the histopathological findings in the first UK series of BRCA1 and BRCA2 mutation carriers with PRCA. The archived histopathological tissue sections of 20 BRCA1/2 mutation carriers with PRCA were collected from histopathology laboratories in England, Ireland and Scotland. The cases were matched to a control group by age, stage and serum PSA level of PRCA cases diagnosed in the general population. Following histopathological evaluation and re-grading according to current conventional criteria, Gleason scores of PRCA developed by BRCA1/2 mutation carriers were identified to be significantly higher (Gleason scores 8, 9 or 10, P=0.012) than those in the control group. Since BRCA1/2 mutation carrier status is associated with more aggressive disease, it is a prognostic factor for PRCA outcome. Targeting screening to this population may detect disease at an earlier clinical stage which may therefore be beneficial.

Delivery of cancer genetics services: The Royal Marsden telephone clinic model

We have conducted a telelink telephone-led cancer genetic counselling model at The Royal Marsden NHS Foundation Trust. The study commenced in March 2004 and evaluation of the clinic was conducted over 17 months from March 2005 to the end of July 2006. A total of 612 patients had telephone consultations during this time, 228 of whom were referred from primary care with a median of 30 patients counselled per month (range of 19-63, depending on staff availability with average of two staff per clinic). Waiting times were measured for General Practitioner referrals and all 228 were counselled within the national target-stipulated 13 weeks (median 6 weeks, range 1-12). An additional 132 patients who were sent appointment letters after receipt of their family history questionnaires did not attend their appointments (18% of all potential referrals) and required recontacting by letter. After telephone counselling, 42% of patients were able to be discharged from the telephone clinic without a subsequent face-to-face appointment, thereby saving resources. The telephone clinic also had a short set-up time with flexibility on timing and day of administration, which would be an advantage in centres where outreach clinic facilities are scarce. The telelink telephone counselling model is highly efficient in triaging high risk individuals for face-to-face counselling as per the Kenilworth model, in effecting concentration of resources and in providing a flexible individual-centred approach to cancer genetic counselling delivery.

Microbial analysis of soil and groundwater from a gasworks site and comparison with a sequenced biological reactive barrier remediation process

AIMS

To investigate the distribution of a polymicrobial community of biodegradative bacteria in (i) soil and groundwater at a former manufactured gas plant (FMGP) site and (ii) in a novel SEquential REactive BARrier (SEREBAR) bioremediation process designed to bioremediate the contaminated groundwater.

METHODS AND RESULTS

Culture-dependent and culture-independent analyses using denaturing gradient gel electrophoresis (DGGE) and polymerase chain reaction (PCR) for the detection of 16S ribosomal RNA gene and naphthalene dioxygenase (NDO) genes of free-living (planktonic groundwater) and attached (soil biofilm) samples from across the site and from the SEREBAR process was applied. Naphthalene arising from groundwater was effectively degraded early in the process and the microbiological analysis indicated a dominant role for Pseudomonas and Comamonas in its degradation. The microbial communities appeared highly complex and diverse across both the sites and in the SEREBAR process. An increased population of naphthalene degraders was associated with naphthalene removal.

CONCLUSION

The distribution of micro-organisms in general and naphthalene degraders across the site was highly heterogeneous. Comparisons made between areas contaminated with polycyclic aromatic hydrocarbons (PAH) and those not contaminated, revealed differences in the microbial community profile. The likelihood of noncultured bacteria being dominant in mediating naphthalene removal was evident.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work further emphasizes the importance of both traditional and molecular-based tools in determining the microbial ecology of contaminated sites and highlights the role of noncultured bacteria in the process.

AIDIT and IMPACT: building research collaborations in targeted prostate cancer screening

AIDIT (Advancing International Co-operation and Developing Infrastructure for Targeted Screening of Prostate Cancer in Men with Genetic Predisposition) is a project funded by the Sixth Framework Programme of the European Community which is endeavouring to facilitate co-operation between European countries in the field of cancer research. The project also aims to raise awareness of familial prostate cancer among health professionals and the public within the associated candidate countries (ACCs) and new member states of the European Union (EU). AIDIT will focus on linking clinical and research teams in the ACCs and new member states with the IMPACT Consortium (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), an international team investigating screening and diagnosis for men with a genetic risk of prostate cancer predisposition genes BRCA1 or BRCA2). Cancer research has been targeted as a high priority for the European Community; however, research is most successful when centralised and well coordinated, avoiding the duplication and fragmentation associated with smaller, isolated studies. AIDIT will consolidate the current IMPACT consortium and allow research partners from across the world to benefit from shared knowledge and experience. To date, the AIDIT team has established a website to facilitate communication between project collaborators (www.impact-study.co.uk), has been represented at several international meetings and has facilitated a conference for the IMPACT study to bring together international research teams, clinicians and policy makers.

The global atmospheric environment for the next generation

Air quality, ecosystem exposure to nitrogen deposition, and climate change are intimately coupled problems: we assess changes in the global atmospheric environment between 2000 and 2030 using 26 state-of-the-art global atmospheric chemistry models and three different emissions scenarios. The first (CLE) scenario reflects implementation of current air quality legislation around the world, while the second (MFR) represents a more optimistic case in which all currently feasible technologies are applied to achieve maximum emission reductions. We contrast these scenarios with the more pessimistic IPCC SRES A2 scenario. Ensemble simulations for the year 2000 are consistent among models and show a reasonable agreement with surface ozone, wet deposition, and NO2 satellite observations. Large parts of the world are currently exposed to high ozone concentrations and high deposition of nitrogen to ecosystems. By 2030, global surface ozone is calculated to increase globally by 1.5 +/- 1.2 ppb (CLE) and 4.3 +/- 2.2 ppb (A2), using the ensemble mean model results and associated +/-1 sigma standard deviations. Only the progressive MFR scenario will reduce ozone, by -2.3 +/- 1.1 ppb. Climate change is expected to modify surface ozone by -0.8 +/- 0.6 ppb, with larger decreases over sea than over land. Radiative forcing by ozone increases by 63 +/- 15 and 155 +/- 37 mW m(-2) for CLE and A2, respectively, and decreases by -45 +/- 15 mW m(-2) for MFR. We compute that at present 10.1% of the global natural terrestrial ecosystems are exposed to nitrogen deposition above a critical load of 1 g N m(-2) yr(-1). These percentages increase by 2030 to 15.8% (CLE), 10.5% (MFR), and 25% (A2). This study shows the importance of enforcing current worldwide air quality legislation and the major benefits of going further. Nonattainment of these air quality policy objectives, such as expressed by the SRES-A2 scenario, would further degrade the global atmospheric environment.

Change the scope of practice of paramedics? An EMS/public health policy perspective

OBJECTIVE

To analyze the potential for expanding the scope of practice of paramedics from public health, health planning, and health policy perspectives, utilizing data covering more than 42,000 emergency patients.

METHODS

The authors conducted a retrospective study of 42,918 patients seen in two Baltimore emergency departments over a six-month period, 5,259 of whom were transported by emergency ambulance. The authors constructed epidemiologic profiles of in-hospital and prehospital patients, and merged ambulance data with discharge diagnoses.

RESULTS

The 42,918 patients had a total of 2,118 different discharge diagnoses. The ten most frequent diagnoses of ambulance-transported patients were convulsions, injuries, asthma, congestive heart failure, chest pain, syncope and collapse, otitis media, abdominal pain, cardiac arrest, and respiratory abnormality. The ten most frequent diagnoses for all ED patients were otitis media, asthma, finger and nonspecific injuries, upper respiratory infections, chest pain, bronchitis, pharyngitis, gastroenteritis, nonspecific viral infections, and urinary tract infections. Infections accounted for 31.6% of the top 50% of diagnoses by volume, followed by injuries (24%) and cardiovascular cases (16.5%). However, 26.9% of ED patients received an assessment and diagnosis of general symptoms (no procedure).

CONCLUSIONS

The high number of diagnoses and the frequency of infections as a primary complaint in this patient sample reconfirm the primacy of the physician in prioritizing patients and assigning treatment pathways. The authors suggest a methodology that may allow properly trained medics to alter some of their role as physician extenders, but suggest that system planners must first ensure that any changes not reduce the public health benefits that each EMS system already provides.

A medically wise approach to expanding the role of paramedics as physician extenders

The authors examined a portion of the complex issue of the scope of practice of paramedics in light of the epidemiologic profile of emergency patients seen at two Baltimore hospitals. They suggest that the same approach could and should be used to help decide on the scope of work of prehospital personnel in any jurisdiction. The findings lead the authors to urge caution toward any potential changes to the work done by medics, because of the enormous breadth of presenting patient conditions. The authors suggest that the epidemiologic profile witnessed in Baltimore would require increased direct physician input on patient destination decisions for all medics who would be working under an expanded scope of functions, and the paper suggests a mechanism for accomplishing this goal. Finally, while there may be compelling economic reasons to change what medics do in the field, this article cautions health care managers to design changes, based on solid evidence, that will have a positive public health impact, and then work to evaluate the character of the impact after changes are implemented.

Health care and its costs for children with perinatally acquired HIV infection

OBJECTIVE

To describe survival patterns, use of health services and related costs for Australian children with perinatally acquired human immunodeficiency virus (HIV) infection.

METHODOLOGY

A retrospective cross-sectional survey was made of 20 children with HIV infection (91% of those diagnosed) and 13 children with maternal antibodies who subsequently seroreverted, treated at 10 medical centres. Details of disease progression and use of health services were obtained from hospital medical records. Monthly costs for three phases of infection were estimated by linking service usage rates with estimates of the unit cost of each service. The average lifetime cost was estimated by combining monthly costs and phase duration estimates from the literature.

RESULTS

Patterns of disease progression were similar to those reported internationally, with a median survival of 8 years. Use of health services increased with severity of illness. Mean monthly costs were $120 per month (1992 Australian dollars) for children with maternal antibodies who subsequently seroreverted, $320 per month for children with HIV infection but no acquired immunodeficiency syndrome (AIDS)-defining illness, and $1830 per month for children with AIDS. The present value of total lifetime cost for a child with HIV infection was $48174, 46% of which was for treatment of AIDS.

DISCUSSION

The mean lifetime cost for a perinatally infected child was just over half that for a man with HIV in Australia. Health service usage and costs were lower for Australian than American children with HIV.

Reverse transcriptase mutations in sequential HIV-1 isolates in a patient with AIDS

Sequential human immunodeficiency virus type 1 (HIV-1) isolates were obtained over a 29-month period from a person before, during, and after AZT therapy. DNA sequence analysis of polymerase chain-amplified reverse-transcriptase gene showed a gradual accumulation of mutations to peak resistance (IC50 2.13 microM AZT) in association with mutations at codons 44, 210, and 369, as well as at 41, 67, 70, and 215. Eight months after cessation of AZT therapy, when an HIV-1 isolate from the patient was again sensitive to AZT, these mutations had all returned to the pretherapy sequence.