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Purpose Femoral lengthening using a circular or mono-lateral frame is a commonly used technique. Fracture at the site of the regenerate bone is a major concern especially following removal of the external fixator. This aim of this study was to assess the rate of fracture of the regenerate bone in this single surgeon series of paediatric patients and determine potential risk factors. Methods Retrospective review of all the femoral lengthening performed by the senior author was performed. The medical and physiotherapy notes were reviewed. The gender, age at time of surgery, disease aetiology, total days in the external fixator and length of the new regenerate bone were recorded. Patients who sustained a regenerate fracture were identified. Results A total of 176 femoral lengthening procedures were performed on 108 patients. Eight regenerate fractures occurred in seven patients (4.5%). The mechanism of injury was a fall in five cases and during physiotherapy in three cases. The regenerate fracture occurred a median number of nine days following removal of frame. There was no significant difference between gender, age at time of surgery, total time in external fixator between those who sustained a regenerate fracture and those patients who did not. A significant difference was noted between the amount of lengthening between the ‘regenerate fracture group’ and the ‘no fracture group’ (50 mm vs 38 mm, respectively; p = 0.029). There was no association between disease aetiology and risk of regenerate fracture. Conclusions Femoral lengthening of more than 50 mm increases the risk of a fracture at the regenerate site regardless of the disease aetiology. We recommend avoidance of aggressive physiotherapy for the initial four weeks following external fixator removal. [ABSTRACT FROM AUTHOR]

An experimental investigation of an above-ferromagnetic resonant self-biased hexagonal ferrite circulator is detailed in this paper. The concept of the "region of opportunity" is invoked to establish a relationship between the ferrite's geometry and its M H large-signal data for self-biased operation. This concept is used to design a working three-port nonreciprocal device that will serve as a basis for experimentally ascertaining best case insertion losses (ILs), return losses (RLs), and/or isolations (ISs) for circulator applications. Furthermore, we show that this nonreciprocal device when externally tuned as a circulator exhibits RLs and ISs of better than 15 dB across a narrow band; the ILs are on the order of 1.5 dB within this same band. This IL is correlated to the best case IL. Results confirm the conclusion that a ferrite with = 4.0 kOe, 4 π Ms = 4.375 kG, and ΔH = 1.862 kOe is suitable for self-biased circulator applications. [ABSTRACT FROM AUTHOR]

Although diabetic patients with rectal cancer have poorer outcomes than their nondiabetic counterparts, few studies have looked at diabetics’ response to therapy as an explanation for this disparity. This study compares the neoadjuvant chemoradiotherapy (CRT) response in diabetic and nondiabetic patients with locally advanced rectal cancers. This is a single-institution, retrospective review of rectal cancer patients who received CRT followed by resection from 1995 to 2006. Pretreatment tumor–node–metastasis (TNM) staging was determined using endorectal ultrasound, computed tomography (CT) scan, and magnetic resonance imaging (MRI); post-treatment staging was determined by pathological review. 110 patients were included; seventeen had diabetes and 93 were nondiabetics. Pretreatment staging was similar in both groups. Sixteen of the diabetics (94%) completed CRT compared to 92% (86/93) of the nondiabetics. Tumor downstaging rates were similar in the two groups (53% in diabetics, 52% in nondiabetics). Nondiabetic patients had a higher rate of nodal downstaging although not statistically significant (67% versus 27%, P = 0.80). While none of the diabetics patients achieved a pathologic complete response (pCR), 23% (21/93) of the nondiabetics did ( P = 0.039). Local progression rates were higher in the diabetic group (24% versus 5%, P = 0.046). Our study shows that neoadjuvant chemoradiotherapy in rectal cancer is less effective in diabetic patients than in nondiabetics. While minimal differences are found in the rate of downstaging, the rate of achieving a complete pathologic response was significantly higher in nondiabetic patients, and in fact was not seen in any of our diabetic patients. This may explain the poorer outcomes seen in diabetic patients with rectal cancer. [ABSTRACT FROM AUTHOR]

Context: A previous study suggested that the combination of a normal D-dimer assay and normal alveolar dead-space fraction is a highly sensitive screening test for pulmonary embolism (PE).Objective: To determine if the combination of a normal alveolar dead-space fraction (volume of alveolar dead space/tidal volume Design: Prospective, noninterventional study conducted in 1998-1999. Study data were obtained prior to standard testing for PE, consisting of radionuclide lung scanning or contrast-enhanced computed tomography and 6-month follow-up plus selective use of venous ultrasonography and pulmonary angiography. Imaging studies were interpreted by blinded observers.Setting: Six urban teaching hospitals in the United States.Patients: A total of 380 hemodynamically stable ED patients aged 18 years or older with suspected acute PE.Main Outcome Measures: Sensitivity and specificity for PE with a positive test defined as having either alveolar dead-space fraction or D-dimer assay results abnormal. Alveolar dead-space fraction was determined by subtracting airway dead space from physiological dead space (determined using the modified Bohr equation) and D-dimer assay, assayed at bedside using 20 microL of arterial blood.Results: Pulmonary embolism was diagnosed in 64 patients (16.8%), of those 20 had an abnormal D-dimer assay result, 3 had an abnormal alveolar dead-space fraction, 40 had abnormal results in both, and 1 had normal results for both tests. The sensitivity for diagnosis of PE was 98.4% (95% confidence interval [CI], 91.6%-100.0%). Among the 316 patients without PE, both D-dimer and dead-space results were normal in 163, for a specificity of 51.6% (95% CI, 46.1%-57.1%). Posterior probability of PE with normal results on both tests was 0.75% (95% CI, 0%-3.4%).Conclusion: In this multicenter study of ED patients, a normal D-dimer assay result plus a normal alveolar dead-space fraction was associated with a low prevalence of PE. [ABSTRACT FROM AUTHOR]

Measurable B-type natriuretic peptides (BNPs), which are largely produced by the left ventricle, include BNP and N-terminal prohormone BNP (NT-proBNP). These proteins are released by cardiomyocytes in response to wall tension and neurohumoral signals, and are established tools in the diagnosis and prognosis of heart failure (HF). We identified 32 articles for entry into evidence tables that presented original data on BNP and/or NT-proBNP in more than 100 patients with acute coronary syndromes (ACS) presenting with chest discomfort with or without dyspnea. Natriuretic peptide (NP) elevation was associated with older age, female sex, hypertension, diabetes, prior HF, prior ischemic heart disease, and reduced renal function. Clinical correlates of elevated blood NP levels included left main or 3-vessel coronary disease, lipid-rich plaques with large necrotic cores in proximal locations, large zones of myocardial ischemia or infarction, no-reflow and impaired perfusion after percutaneous intervention, reduced left ventricular ejection fraction, higher Killip classification, and the development of cardiogenic shock. All studies indicated that after adjustment for baseline predictors and clinical risk scores, elevated NP concentrations were independently predictive of the development of HF and all-cause mortality. In contrast, studies did not consistently demonstrate that NPs were predictive of myocardial infarction and rehospitalization for ACS. In addition to baseline measurement, there is consensus that repeat testing at 4 to 12 weeks and 6 to 12 months in follow-up is helpful in the anticipation of late cardiac sequelae and may assist in assessing prognosis and guiding management. [ABSTRACT FROM AUTHOR]

There have been considerable advances in the evaluation of suspected acute coronary syndromes (ACS): sophistication of the clinical examination, electrocardiography, risk prediction scores, multiple blood biomarkers, and rapid cardiovascular imaging. Integration of information remains a formidable challenge for the physician in the setting of time-sensitive clinical decision making. In addition to conventional panels of biomarkers, there are novel entities that may be able to signal different stages of the acute event, including plaque disruption, atherothrombosis, ischemic damage, tissue hypoxia, and oxidative stress. The natriuretic peptides are normal myocyte products that reflect myocardial tissue response to neurohormonal and mechanical forces that rapidly change during an ACS event. This article summarizes major advancements in the integrative use of multiple blood biomarkers and cardiovascular imaging in the diagnosis, prognosis, and management of ACS. [ABSTRACT FROM AUTHOR]

Approximately 6 million patients are evaluated annually in US emergency departments for acute chest pain. The delineation of the presence or absence of acute coronary syndromes in these patients must be accurate and efficient in order to prevent missed diagnoses. Coronary computed tomography angiography has great promise as a tool to expedite the triage of patients with acute chest pain to early discharge or further inpatient diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Characteristics of stands of urban forest in Halifax. Nova Scotia, were analyzed with regards to tree-species composition and carbon sequestration. Older stands in residential and institutional neighbourhoods are dominated by non-native species of trees, thus limiting their usefulness in terms of protection of indigenous biodiversity values. These stands do, however, provide substantial ecosystem service in terms of carbon storage, because they are dominated by relatively largetrees with an almost closed canopy (averaging 83% cover), and supporting a relatively large stand biomass (averaging 131 t/ha of above-ground tree biomass). In comparison, younger residential neighbourhoodshave larger frequencies of native tree species, reflecting a recent trend to preserving some natural forest as buffer strips between properties. However, the proportion of native species of trees in the younger neighbourhoods is expected to decrease with time, because non-indigenous species are the strongly dominant choice among recent plantings by homeowners. Because of recent disturbance, urban forest in younger neighbourhoods has a relatively small biomass, but this should increase with succession. Natural-forest urban parks have a tree-species composition and stand structure that are similar to that of more remote, natural forests. [ABSTRACT FROM AUTHOR]