Wave intensity analysis and its application to the coronary circulation

Wave intensity analysis (WIA) is a technique developed from the field of gas dynamics that is now being applied to assess cardiovascular physiology. It allows quantification of the forces acting to alter flow and pressure within a fluid system, and as such it is highly insightful in ascribing cause to dynamic blood pressure or velocity changes. When co-incident waves arrive at the same spatial location they exert either counteracting or summative effects on flow and pressure. WIA however allows waves of different origins to be measured uninfluenced by other simultaneously arriving waves. It therefore has found particular applicability within the coronary circulation where both proximal (aortic) and distal (myocardial) ends of the coronary artery can markedly influence blood flow. Using these concepts, a repeating pattern of 6 waves has been consistently identified within the coronary arteries, 3 originating proximally and 3 distally. Each has been associated with a particular part of the cardiac cycle. The most clinically relevant wave to date is the backward decompression wave, which causes the marked increase in coronary flow velocity observed at the start of the diastole. It has been proposed that this wave is generated by the elastic re-expansion of the intra-myocardial blood vessels that are compressed during systolic contraction. Particularly by quantifying this wave, WIA has been used to provide mechanistic and prognostic insight into a number of conditions including aortic stenosis, left ventricular hypertrophy, coronary artery disease and heart failure. It has proven itself to be highly sensitive and as such a number of novel research directions are encouraged where further insights would be beneficial.

Computer hexapod-assisted orthopaedic surgery provides a predictable and safe method of femoral deformity correction

Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

Patients and Methods

The medical records and radiographs of all patients who underwent CHAOS for femoral deformity at our institution between 2005 and 2011 were retrospectively reviewed. Records were available for all 55 consecutive procedures undertaken in 49 patients with a mean age of 35.6 years (10.9 to 75.3) at the time of surgery.

Results

Patients were assessed at a mean interval of 44 months (6 to 90) following surgery. The indications were broad; the most common were vitamin D resistant rickets (n = 10), growth plate arrest (n = 6) and post-traumatic deformity (n = 20). Multi-planar correction was required in 33 cases. A single level osteotomy was performed in 43 cases. Locking plates were used to stabilise the osteotomy in 33 cases and intramedullary nails in the remainder. Complications included two nonunions, one death, one below-knee deep vein thrombosis, one deep infection and one revision procedure due to initial under-correction. There were no neurovascular injuries or incidence of compartment syndrome.

Conclusion

This is the largest reported series of femoral deformity corrections using the CHAOS technique. This series demonstrates that precise intra-operative realignment is possible with a hexapod external fixator prior to definitive stabilisation with contemporary internal fixation. This combination allows reproducible correction of complex femoral deformity from a wide variety of diagnoses and age range with a low complication rate. Cite this article: Bone Joint J 2017;99-B:283–8.

But who will make the visits? A patient-related information system for management in district nursing

District nurses in Barnsley, UK, have for many years used a patient classification system based on ‘Criteria for Care’, whose value in practical management terms has established itself into the routine of the information system used. This is a descendant of FIP, now known as TCCS (Total Care Community System). ‘Criteria for Care’ was, however, hospital based and an independent validity check was required for community use. This was carried out in Belfast, Northern Ireland, where research produced a system for patient classification, workload analysis and skillmix analysis which was generated by nurses and acted both as a validity check and further development of the system used in Barnsley.

The management information matrix, which is the outcome of this paper, is generated from practitioners using guidelines agreed by them, and yields management information of a directly practical value.

The system presented is now implemented and uses data updated daily, if required, to produce a spreadsheet covering team workload index, a workload profile, and measures of pressure of work on each nurse, patient acuity [1], and a quality of care index. From this it is possible to adjust skillmix and staffing levels to create equity of pressure across teams and to match nursing skillmix to patient classification in the light of a quality index from each team.

From a GP attachment and a team perspective this information can be utilized in conjunction with contract monitoring data in order to review district nursing activity. This will enable workloads to be reviewed and could facilitate integrated team working within the practice.

Acute Flaccid Paralysis: The New, The Old, and The Preventable

Acute flaccid paralysis (AFP) has a changing epidemiology with ongoing polio outbreaks and emerging causes such as nonpolio enteroviruses and West Nile virus (WNV). We report a case of AFP from the Horn of Africa that was initially classified as probable polio but subsequently found to be due to WNV.

Overweight across the life course and adipokines, inflammatory and endothelial markers at age 60-64 years: evidence from the 1946 birth cohort

Background/Objectives:

There is growing evidence that early development of obesity increases cardiovascular risk later in life, but less is known about whether there are effects of long-term excess body weight on the biological drivers associated with the atherosclerotic pathway, particularly adipokines, inflammatory and endothelial markers. This paper therefore investigates the influence of overweight across the life course on levels of these markers at retirement age.

Subjects/Methods:

Data from the Medical Research Council National Survey of Health and Development (n=1784) were used to examine the associations between overweight status at 2, 4, 6, 7, 11, 15, 20, 26, 36, 43, 53 and 60–64 years (body mass index (BMI)⩾25 kg m⁻² for adult ages and gender-specific cut-points for childhood ages equivalent to BMI⩾25 kg m⁻²) and measurements of adipokines (leptin and adiponectin), inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6)) and endothelial markers (E-selectin, tissue plasminogen activator (t-PA) and von Willebrand factor) at 60–64 years. In addition, the fit of different life course models (sensitive periods/accumulation) were compared using partial F-tests.

Results:

In age- and sex-adjusted models, overweight at 11 years and onwards was associated with higher leptin, CRP and IL-6 and lower adiponectin; overweight at 15 years and onwards was associated with higher E-selectin and t-PA. Associations between overweight at all ages earlier than 60–64 with leptin, adiponectin, CRP and IL-6 were reduced but remained apparent after adjustment for overweight at 60–64 years; whereas those with E-selectin and t-PA were entirely explained. An accumulation model best described the associations between overweight across the life course with adipokines and inflammatory markers, whereas for the endothelial markers, the sensitive period model for 60–64 years provided a slightly better fit than the accumulation model.

Conclusions:

Overweight across the life course has a cumulative influence on adipokines, inflammatory and possibly endothelial markers. Avoidance of overweight from adolescence onwards is likely important for cardiovascular disease prevention.

An internal ribosome entry site in the 5' untranslated region of epidermal growth factor receptor allows hypoxic expression

The expression of epidermal growth factor receptor (EGFR/ERBB1/HER1) is implicated in the progress of numerous cancers, a feature that has been exploited in the development of EGFR antibodies and EGFR tyrosine kinase inhibitors as anti-cancer drugs. However, EGFR also has important normal cellular functions, leading to serious side effects when EGFR is inhibited. One damaging characteristic of many oncogenes is the ability to be expressed in the hypoxic conditions associated with the tumour interior. It has previously been demonstrated that expression of EGFR is maintained in hypoxic conditions via an unknown mechanism of translational control, despite global translation rates generally being attenuated under hypoxic conditions. In this report, we demonstrate that the human EGFR 5′ untranslated region (UTR) sequence can initiate the expression of a downstream open reading frame via an internal ribosome entry site (IRES). We show that this effect is not due to either cryptic promoter activity or splicing events. We have investigated the requirement of the EGFR IRES for eukaryotic initiation factor 4A (eIF4A), which is an RNA helicase responsible for processing RNA secondary structure as part of translation initiation. Treatment with hippuristanol (a potent inhibitor of eIF4A) caused a decrease in EGFR 5′ UTR-driven reporter activity and also a reduction in EGFR protein level. Importantly, we show that expression of a reporter gene under the control of the EGFR IRES is maintained under hypoxic conditions despite a fall in global translation rates.

Physical activity levels and patients' expectations of physical activity during acute general medical admission

Bedrest during hospital admission is common and might be harmful. There is scarce published evidence that quantifies physical activity levels and expectations regarding physical activity of general medical patients during an acute inpatient stay. The current study aimed to investigate physical activity levels and expectations regarding physical activity in general medical patients at a large Australian teaching hospital. A convenience sample of 24 general medical patients was observed at 10-min intervals in one day between 8:00 and 17:00 and their physical activity status recorded. Participants completed a questionnaire regarding their expectations of physical activity during illness and hospital admission. Patients were observed to be in bed 51% of the time, were sitting out of bed 43% of the time, were standing 1% of the time and were walking 5% of the time. One third of participants (n = 8) were not observed to walk during the observation period. Questionnaire data indicated that nine (38%) participants expected to remain in bed while in hospital. General medical patients had low levels of physical activity during their hospital stay, which was consistent with many participants' expectations of appropriate activity when in hospital. If physical activity is an important part of acute general medical patient management, then patient expectations of the appropriateness of physical activity need to be addressed and methods to increase physical activity implemented.

Coverage of the English national human papillomavirus (HPV) immunisation programme among 12 to 17 year-old females by area-level deprivation score, England, 2008 to 2011

The English national human papillomavirus (HPV) immunisation programme has offered vaccination to girls aged 12 years at the start of each school year since September 2008. A catch-up programme has offered vaccination to girls up to 18 years. Delivery is predominantly school-based, with some general practitioner (GP)-based immunisation. The relationship between HPV immunisation coverage and deprivation (index of multiple deprivation, IMD) was assessed by geographical area (N=151) for each school year offered the HPV vaccine between 2008 to 2011 using the Spearman’s rank correlation coefficient, and compared to that for adequate cervical screening of women aged 25 to 49 years. Coverage at age 12 showed no significant association with IMD at the area-level (p=0.12). Within the catch-up years, there was some suggestion of higher deprivation being associated with lower coverage. This was not significant for girls offered immunisation under 16 years (in compulsory education) (p=0.09), but was more marked and statistically significant for older girls (p<0.0001). The proportion of women aged 25 to 49 years with an adequate cervical screen was negatively associated with deprivation (p<0.0001). School-based HPV immunisation delivery appears to be successfully reducing inequalities in cervical cancer control at area-level. However, the catch-up cohorts above the age of compulsory education may face increased inequality. Further investigation is needed into individual-level factors associated with coverage.

Stem cell therapy for stress urinary incontinence: a systematic review in human subjects

PURPOSE

To systematically evaluate the current evidence on the safety and efficacy of stem cell therapy (SCT) in stress urinary incontinence (SUI) to allow objective comparison with existing surgical techniques.

METHODS

Systematic literature search of Medline from years 1946-2012 using terms: "stem", "cell", "stress", "urinary", and "incontinence". Included studies presented empirical data on the treatment of SUI using SCT.

OUTCOMES

adverse events, incontinence, quality of life, urodynamic, transurethral ultrasound and urethral EMG findings.

RESULTS

Eight studies met inclusion criteria (seven observational and one randomized). Quality score: median 10.75 of 20 (range 2-12.5). Adverse events: one patient had bladder perforation and two procedures could not be completed due to pain. Temporary urinary retention and cystitis were also reported. Incontinence score: Four studies describe significant improvement. Quality of life: significant improvement in four studies. Urodynamic outcomes: four studies show significant improvement in contractility of urethral sphincter; three studies demonstrate no change in bladder capacity and significant reduction in residual volume; significant improvement in urinary flow three studies, although two found no difference; increase in leak point pressure and detrusor pressure in three studies. Urethral ultrasound: three studies found significant increases in rhabdosphincter thickness and contractility. Urethral EMG: two studies found significant increases in the EMG at rest and at contraction.

CONCLUSION

Data suggest that SC treatment for SUI is safe and effective in the short term. However, the quality and maturity of the data are limited. Robust data from better quality studies comparing this to current surgical techniques are needed.

A dedicated clinic for HIV-positive individuals over 50 years of age: a multidisciplinary experience

The HIV-infected population is ageing. Issues including polypharmacy and co-morbidities led us to develop a dedicated clinic for HIV-infected individuals over 50. We describe our service evaluation after two years. The over 50 clinic commenced in January 2009. The team comprises a registrar, consultant, nurse practitioner and is supported by a pharmacist and mental health services. Patients undergo a full medication and drug interactions review, neurocognitive assessment, adherence self-assessment and investigations including therapeutic drug monitoring (TDM), coronary artery calcium scores (CACS) and bone mineral density. Over two years of activity, 150 patients attended the service. Median (range) age was 58 (50-88), all were on combined antiretroviral therapy and 38% (57/150) were on ≥3 non-HIV drugs. CACS was high (>90th centile) in 14%. Thirty-eight percent had osteopaenia and 18% had osteoporosis requiring treatment. Thirteen out of 125 men had an increased prostate specific antigen, four were diagnosed with prostate cancer. Drug interaction, TDM and neurocognitive assessments were useful for several patients. Asymptomatic patients over 50 in long-term follow-up had new pathologies detected through targeted screening. The clinic has improved general practitioner (GP) liaison and facilitated closer working relationships with other specialties. Patients have reacted positively to the clinic, particularly as many do not routinely access their GP.

Adverse incidents resulting in exposure to body fluids at a UK dental teaching hospital over a 6-year period

Background:

The safety and protection of patients and health care workers is of paramount importance in dentistry, and this includes students in training who provide clinical care. Given the nature of dental care, adverse incidents can and do occur, exposing health care workers to body fluids and putting them at risk of infection, including contracting a blood-borne virus. The aim of this research was to analyze trends in the volume, rate, nature, management, and outcome of adverse incidents reported at one dental teaching hospital from 2005 to 2010.

Methods:

Descriptive analysis of trends in the volume, rate, nature, management, and outcome of adverse incidents reported at one dental teaching hospital over a six-year period was undertaken in relation to the level of outpatient and day surgery activity.

Results:

In total, 287 incidents were reported over a six-year period, which amounted to 0.039% of outpatient or day surgery appointments. Nearly three quarters of all the incidents (n = 208, 72%) took place during treatment or whilst clearing away after the appointment. The most frequent incidents were associated with administration of local anesthetic (n = 63, 22%), followed by burs used in dental hand pieces (n = 51, 18%).

Conclusion:

This research confirms that adverse incidents are a feature of dental hospitals and reports the common sources. The importance of accurate and consistent reporting of data to ensure that these issues are monitored to inform action and reduce risks to staff, students, and patients are highlighted.