Characterisation of Crevice and Pit Solution Chemistries Using Capillary Electrophoresis with Contactless Conductivity Detector

The ability to predict structural degradation in-service is often limited by a lack of understanding of the evolving chemical species occurring within a range of different microenvironments associated with corrosion sites. Capillary electrophoresis (CE) is capable of analysing nanolitre solution volumes with widely disparate concentrations of ionic species, thereby producing accurate and reliable results for the analysis of the chemical compositions found within microenvironment corrosion solutions, such as those found at crevice and pit corrosion sites. In this study, CE with contactless conductivity detection (CCD) has been used to characterize pitting and crevice corrosion solution chemistries for the first time. By using the capillary electrophoresis with contactless conductivity detection (CE-CCD) system, direct and simultaneous detection of seven metal cations (Cu²⁺, Ni²⁺, Fe³⁺, Fe²⁺, Cr³⁺, Mn²⁺, and Al³⁺) and chloride anions was achieved with a buffer solution of 10 mM 2,6-pyridinedicarboxylic acid and 0.5 mM cetyltrimethylammonium hydroxide at pH 4 using a pre-column complexation method. The detection limits obtained for the metal cations and chloride anions were 100 and 10 ppb, respectively. The CE-CCD methodology has been demonstrated to be a versatile technique capable of speciation and quantifying the ionic species generated within artificial pit (a pencil electrode) and crevice corrosion geometries for carbon steels and nickel-aluminium bronze, thus allowing the evolution of the solution chemistry to be assessed with time and the identification of the key corrosion analyte targets for structural health monitoring.     

Sensory motor systems of artificial and natural hands

The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.     

Influence of aminoglutethimide on plasma levels of medroxyprogesterone acetate

To confirm that concomitant administration of aminoglutethimide (AG) reduces plasma levels of medroxyprogesterone acetate (MPA), MPA levels were assayed in six patients with advanced breast cancer receiving the two agents. Patients had disease resistant to AG and were studied during conversion to therapy with MPA. Hydrocortisone was discontinued at the commencement of study and MPA introduced and given at a constant dose of 800 mg daily while AG was reduced in dose from 250 mg b.d. to 125 mg b.d. and then discontinued. MPA levels were measured after two weeks at each dose of AG and after two weeks on MPA alone. Mean MPA levels showed a progressive and significant (P less than 0.01) rise as the AG dose was reduced--180 ng ml-1, 250 ng ml-1 and 740 ng ml-1 respectively. MPA levels were always in excess of the accepted therapeutic level of 100 ng ml-1 and plasma cortisol levels fell in parallel with the rise in MPA levels.     

Changing patterns of demand for chemical pathology on-call services in four North Dublin hospitals

Developments in the demand for out-of-hours chemical pathology over the period when the Richmond and Jervis St. hospitals amalgamated and moved to a new hospital at Beaumont are presented alongside the similar workload from Blanchardstown Hospital whose laboratory services remained unchanged during the period. The requests from the Accident and Emergency (A&E) departments before and after midnight are also detailed. Data is presented from the Richmond from 1986 and from the other hospitals from 1987 using the first 17 rostered on-call nights of each year. With the exception of Beaumont where the diversity of tests requested was such that the working day had effectively extended, the work load consisted largely of urea and electrolytes, glucose, blood gases and amylase. The demand continued to rise. In Blanchardstown, the total number of patient specimens rose by 39% over two years and the volume increase in A&E was 69% over the same period. The number of specimens from inpatients at Beaumont in 1989 was 49% greater than the combined total from Jervis St. and the Richmond in 1987 and the total patient specimens rose by 14% from 1988 to 1989.     

Effects of human placental lactogen on the expression of CD163 and CD14 on human monocytes in culture

The effect of human placental lactogen (hPL), a member of the somatomammotrophin family, on the regulation of the scavenger receptor molecules CD14 and CD163 on human monocytes cultured for 48h was investigated. Cells were cultured in the presence or absence of the hormone and also in the presence or absence of IFN-gamma and dexamethasone. Monocytes cultured in the presence of hPL showed a significant increase in the expression of CD14 in both males and females compared to background. When IFN-gamma and dexamethasone were added to the cultures, CD14 expression was decreased and was not rescued by the presence of hPL. hPL alone had no effect on the expression of CD163 on cultured monocytes from either gender, although cells cultured in the presence of IFN-gamma and dexamethasone showed a profound increase in their expression of CD163. This expression was augmented further by the presence of hPL in the cultures over a 48-h period. These results support the hypothesis of a potential role of this hormone in the regulation of the innate immune response.     

An economic model for the prevention of MRSA infections after surgery: non-glycopeptide or glycopeptide antibiotic prophylaxis?

Aim  

Surgical site infection is commonly caused by Staphylococcus aureus. The multiresistant strains (MRSA) are resistant to most antibiotic prophylaxis regimens. Our aim was to explore whether there is a threshold of MRSA prevalence at which switching to routine glycopeptide-based antibiotic prophylaxis becomes cost-effective.     

Assessment of non-ST-segment elevation acute coronary syndromes with cardiac magnetic resonance imaging

OBJECTIVES: The goal of this study was to determine: 1) if the presence of significant coronary stenosis in patients presenting with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) can be predicted by cardiac magnetic resonance (CMR) imaging; and 2) if the analysis of several CMR methods improves its diagnostic yield compared with analysis of individual methods. BACKGROUND: With modern acquisition techniques, several CMR methods for the assessment of coronary artery disease (CAD) can be combined in a single noninvasive scanning session. Such a multicomponent CMR examination has not previously been applied to a large patient population, in particular those with a high prevalence of CAD in an acute situation. METHODS: Sixty-eight patients presenting with NSTE-ACS underwent CMR imaging of myocardial function, perfusion (rest and adenosine-stress), viability (by late contrast enhancement), and coronary artery anatomy. Visual analysis of CMR was carried out. First, all CMR data were reviewed in combination ("comprehensive analysis"). In further separate analyses, each CMR method was analyzed individually. The ability of CMR to detect coronary stenosis >/=70% on X-ray angiography was determined. RESULTS: Comprehensive CMR analysis yielded a sensitivity of 96% and a specificity of 83% to predict the presence of significant coronary stenosis and was more accurate than analysis of any individual CMR method; CMR was significantly more sensitive and accurate than the Thrombolysis In Myocardial Infarction risk score (p < 0.001). CONCLUSIONS: Cardiac magnetic resonance imaging accurately predicts the presence of significant CAD in patients with NSTE-ACS. In this study, a comprehensive analysis of several CMR methods improved the accuracy of the test.     

Congenital brachial palsy: incidence,causes, and outcome in the United Kingdom and Republic of Ireland

OBJECTIVES: To determine the incidence and study the causes and outcome of congenital brachial palsy (CBP). DESIGN: Active surveillance of newborn infants using the British Paediatric Surveillance Unit notification system and follow up study of outcome at 6 months of age. SETTING: The United Kingdom and Republic of Ireland. PARTICIPANTS: Newborn infants presenting with a flaccid paresis of the arm (usually one, rarely both) born between April 1998 and March 1999. MAIN OUTCOME MEASURES: Extent of the lesion at birth and degree of recovery at 6 months of age. FINDINGS: There were 323 confirmed cases giving an incidence of 0.42 per 1000 live births (1 in 2300). Significant associated risk factors in comparison with the normal population were shoulder dystocia (60% v 0.3%), high birth weight with 53% infants weighing more than the 90th centile, and assisted delivery (relative risk (RR) 3.4, 95% confidence interval (CI) 2.9 to 3.9, p = 0.0001). There was a considerably lower risk of CBP in infants delivered by caesarean section (RR 7, 95% CI 2 to 56, p = 0.002). At about 6 months of age, about half of the infants had recovered fully, but the remainder showed incomplete recovery including 2% with no recovery. The relative risk of partial or no recovery in infants with extensive lesions soon after birth compared with those with less extensive lesions was 11.28 (95% CI 2.38 to 63.66, p = 0.000005). CONCLUSIONS: The incidence of CBP in the United Kingdom and Republic of Ireland is strikingly similar to that previously reported nearly 40 years ago. Most cases are due to trauma at delivery, which is not necessarily excessive or inappropriate. Given the uncertainty about the appropriate management of these infants, serious consideration should be given to a formal clinical trial of microsurgical nerve repair.