Instrumentation and signal processing for the detection of heavy water using off axis-integrated cavity output spectroscopy technique.

An experimental setup is developed for the trace level detection of heavy water (HDO) using the off axis-integrated cavity output spectroscopy technique. The absorption spectrum of water samples is recorded in the spectral range of 7190.7 cm-1-7191.5 cm-1 with the diode laser as the light source. From the recorded water vapor absorption spectrum, the heavy water concentration is determined from the HDO and water line. The effect of cavity gain nonlinearity with per pass absorption is studied. The signal processing and data fitting procedure is devised to obtain linear calibration curves by including nonlinear cavity gain effects into the calculation. Initial calibration of mirror reflectivity is performed by measurements on the natural water sample. The signal processing and data fitting method has been validated by the measurement of the HDO concentration in water samples over a wide range from 20 ppm to 2280 ppm showing a linear calibration curve. The average measurement time is about 30 s. The experimental technique presented in this paper could be applied for the development of a portable instrument for the fast measurement of water isotopic composition in heavy water plants and for the detection of heavy water leak in pressurized heavy water reactors.

A walking program for people with severe knee osteoarthritis did not reduce pain but may have benefits for cardiovascular health: a phase II randomised controlled trial.

OBJECTIVE: The primary aim was to evaluate the effect of a dosed walking program on knee pain for patients with severe knee osteoarthritis (OA). Secondary aims evaluated the effects on cardiovascular health, function and quality of life. DESIGN: Participants with severe knee OA and increased cardiovascular risk were randomly assigned to a 12-week walking program of 70 min/week of at least moderate intensity, or to usual care. The primary outcome was knee pain (0-10). Secondary outcomes were of cardiovascular risk including physical activity, blood pressure, blood lipid and glucose levels, body mass index and waist circumference; WOMAC Index scores; physical function; and quality of life. RESULTS: Forty-six participants (23 each group) were recruited. Sixteen participants (70%) adhered to the walking program. Intention to treat analysis showed no between-group difference in knee pain. The walking group had increased odds of achieving a healthy systolic blood pressure (OR = 5.7, 95% CI 1.2-26.9), and a faster walking speed (Mean Difference (MD) = 0.12 m/s, 95% CI 0.02-0.23). Per protocol analysis based on participant adherence showed the walking group had more daily steps (MD = 1345 steps, 95% CI 365-2325); more time walking (MD = 18 min/day, 95% CI 5-31); reduced waist circumference (MD = -5.3 cm, 95% CI -10.5 to -0.03); and increased knee stiffness (MD = 0.9 units, 95% CI 0.07-1.8). CONCLUSIONS: Patients with severe knee OA prescribed a 12-week walking program of 70 min/week may have had cardiovascular benefits without decreasing knee pain. Australian New Zealand Clinical Trials Registry ACTRN12615000015549.

[Ligamentun teres of the hip. Bibliographic revision]. / Ligamento teres de la cadera. Revisión bibliográfica.

The role and function of the ligamentum teres has drawn our attention in the last years due to the increasing and performance in hip arthroscopy, few is written in the literature, this is why we proposed to perform and assessed a review on the current literature of the anatomy, function, diagnose and rupture of the ligamentum teres of the hip.

La función del ligamento teres de la cadera ha llamado la atención en los últimos años debido al incremento y a la realización de la artroscopía de cadera, la información en la literatura es escasa, por ello nos propusimos realizar una revisión bibliográfica sobre los conceptos actuales, su anatomía, función, biomecánica, diagnóstico y rupturas del ligamento de teres de la cadera.

The maximum tolerated dose of walking for people with severe osteoarthritis of the knee: a phase I trial.

OBJECTIVE: To determine how much physical activity, in the form of walking, can be safely and feasibly tolerated for people with severe knee osteoarthritis (OA). DESIGN: Phase I dose response trial with escalating walking doses of 10, 20, 35, 50, 70, and 95 min over 1 week, were prescribed non-randomly to people with severe knee OA. The primary stopping rule was a substantial increase in knee pain. The primary outcomes were an estimation of the maximum tolerated dose of walking; and the proportion of people who did not complete the dose for feasibility reasons. The secondary outcomes were pain, stiffness and activity limitation Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). RESULTS: Twenty-four participants (13 women) aged 53-83 years, and average body mass index (BMI) of 34 kg/m(2) (SD 9) were recruited. Three participants were assigned to each dose between 10 and 70 min, and nine participants assigned to the 95-min dose. The trial was stopped at 95 min due to the maximum number of adverse events occurring at this dose. Therefore, the maximum tolerated dose was 70 min. No participant stopped due to reasons related to feasibility. There was a moderate association between dose and increased activity (linear R(2) = 0.31, cubic R(2) = 0.69) and reduced stiffness (linear R(2) = 0.20, cubic R(2) = 0.52), with increased benefits at moderate to higher doses. CONCLUSIONS: There is preliminary evidence that 70 min per week of moderate intensity supervised walking was safe and feasible for people with severe OA of the knee; for higher doses there was a risk of exacerbating knee pain levels.

Readiness factors for lean implementation in healthcare settings--a literature review.

PURPOSE: The purpose of this paper is to determine the readiness factors that are critical to the application and success of lean operating principles in healthcare organizations through a review of relevant literature. DESIGN/METHODOLOGY/APPROACH: A comprehensive review of literature focussing on lean and lean healthcare was conducted. FINDINGS: Leadership, organizational culture, communication, training, measurement, and reward systems are all commonly attributed readiness factors throughout general change management and lean literature. However, directly related to the successful implementation of lean in healthcare is that a setting is able to authorize a decentralized management style and undertake an end-to-end process view. These can be particularly difficult initiatives for complex organizations such as healthcare settings. RESEARCH LIMITATIONS/IMPLICATIONS: The readiness factors identified are based on a review of the published literature. The external validity of the findings could be enhanced if tested using an empirical study. PRACTICAL IMPLICATIONS: The readiness factors identified will enable healthcare practitioners to be better prepared as they begin their lean journeys. Sustainability of the lean initiative will be at stake if these readiness factors are not addressed. ORIGINALITY/VALUE: To the best of the knowledge, this is the first paper that provides a consolidated list of key lean readiness factors that can guide practice, as well as future theory and empirical research.

Arthroscopic femoral osteochondroplasty for cam lesions with isolated acetabular chondral damage.

This study evaluates the outcome of arthroscopic femoral osteochondroplasty for cam lesions of the hip in the absence of additional pathology other than acetabular chondral lesions. We retrospectively reviewed 166 patients (170 hips) who were categorised according to three different grades of chondral damage. The outcome was assessed in each grade using the modified Harris Hip Score (MHHS) and the Non-Arthritic Hip Score (NAHS). Overall, at the last follow-up (mean 22 months, 12 to 72), the mean MHHS had improved by 15.3 points (95% confidence interval (CI), 8.9 to 21.7) and the mean NAHS by 15 points (95% CI, 9.4 to 20.5). Significantly better results were observed in hips with less severe chondral damage. Microfracture in limited chondral lesions showed superior results. Arthroscopic femoral osteochondroplasty for cam impingement with microfracture in selected cases is beneficial. The outcome correlates with the severity of acetabular chondral damage.

Arthroscopic excision of a giant-cell tumour of the ligamentum teres.

Primary giant-cell tumour of soft tissue arising in the ligamentum teres has not been previously described. We report a case of such a tumour in a 46-year-old woman. The lesion was only detected at the time of hip arthroscopy despite pre-operative MRI being performed. It was successfully excised arthroscopically with resolution of the symptoms.

Birmingham hip resurfacing: is acetabular bone conserved?

Hip resurfacing is a bone-conserving procedure with respect to proximal femoral resection, but there is debate in the literature as to whether the same holds true for the acetabulum. We have investigated whether the Birmingham hip resurfacing conserves acetabular bone. Between 1998 and 2005, 500 Birmingham hip resurfacings were performed by two surgeons. Between 1996 and 2005 they undertook 700 primary hip replacements, with an uncemented acetabular component. These patients formed the clinical material to compare acetabular component sizing. The Birmingham hip resurfacing group comprised 350 hips in men and 150 hips in women. The uncemented total hip replacement group comprised 236 hips in men and 464 hips in women. Age- and gender-matched analysis of a cohort of patients for the sizes of the acetabular components required for the two types of replacement was also undertaken. Additionally, an analysis of the sizes of the components used by each surgeon was performed. For age-matched women, the mean outside diameter of the Birmingham hip resurfacing acetabular components was 2.03 mm less than that of the acetabular components in the uncemented total hip replacements (p < 0.0001). In similarly matched men there was no significant difference (p = 0.77). A significant difference was also found between the size of acetabular components used by the two surgeons for Birmingham hip resurfacing for both men (p = 0.0015) and women (p = 0.001). In contrast, no significant difference was found between the size of acetabular components used by the two surgeons for uncemented total hip replacement in either men or women (p = 0.06 and p = 0.14, respectively). This suggests that variations in acetabular preparation also influence acetabular component size in hip resurfacing.

Measurement of the dose of radiation to the surgeon during surgery to the foot and ankle.

We carried out a prospective study over a period of 12 months to measure the exposure to radiation of the hands of a dedicated foot and ankle surgeon. A thermoluminescent dosimeter ring (TLD) was used to measure the cumulative dose of radiation. Fluoroscopy was used in operations on the foot and ankle. The total screening time was 3028 s, with a mean time per procedure of 37.4 s (0.6 to 197). This correlated positively with the number of procedures performed (r = 0.92, p < 0.001), and with the dose of radiation in both the left (r = 0.85, p = 0.0005) and right TLDs (r = 0.59, p = 0.419). There was no significant difference in the dose of radiation between the two hands (t-test, p = 0.62). The total dose to the right TLD over the 12 months was 2.4 millisieverts. This is a simple and convenient method for evaluating the exposure of a single surgeon to radiation. The radiation detected was well below the annual dose limit set by the International Commission on Radiological Protection.

Femoral stem tip orientation and surgical approach in total hip arthroplasty.

INTRODUCTION: A posterior entry point, a neutral tip position and neutral stem alignment are recommended to avoid a thin cement mantle and ensure an optimal outcome in total hip arthroplasty (THA). Our aim was to highlight any influence of surgical approach in obtaining an optimal stem orientation. METHODS: We examined the post-operative, digitised radiographs of 100 (50 each group) polished, tapered Exeter THA, inserted via the antero-lateral or posterior approaches. Stem tip position was assessed in both coronal and sagittal planes and stem alignment was assessed in the coronal plane. RESULTS: There was a significant difference between the two approaches in the sagittal stem tip position only (p=0.01). DISCUSSION: Our results illustrate that a neutral stem tip position in THA is significantly more difficult to obtain with an antero-lateral approach, when compared to the posterior approach. A posterior approach to the hip avoids the cuff of glutei that can lever the proximal stem anteriorly causing an anterior entry point and a posterior stem tip position. We also illustrate how the anatomy of the proximal femur in the sagittal plane makes a neutral stem alignment difficult to achieve with either approach.

Five-year prospective clinical and radiological results of a new cannulated cemented polished Tri-Taper femoral stem.

We describe the results at five years of a prospective study of a new tri-tapered polished, cannulated, cemented femoral stem implanted in 51 patients (54 hips) with osteoarthritis. The mean age and body mass index of the patients was 74 years and 27.9, respectively. Using the anterolateral approach, half of the stems were implanted by a consultant orthopaedic surgeon and half by six different registrars. There were three withdrawals from the study because of psychiatric illness, a deep infection and a recurrent dislocation. Five deaths occurred prior to five-year follow-up and one patient withdrew from clinical review. In the remaining 51 hips the mean pre-operative Oxford hip score was 47 points which decreased to 19 points at five years (45 hips). Of the stems 49 (98%) were implanted within 1 degrees of neutral in the femoral canal. The mean migration of the stem at five years was 1.9 mm and the survivorship for aseptic loosening was 100%. There was no significant difference in outcome between the consultant and registrar groups. At five years, the results were comparable with those of other polished, tapered, cemented stems. Long-term surveillance continues.

The Oxford hip scores for primary and revision hip replacement.

We have used the Oxford hip score to monitor the progress of 1908 primary and 279 revision hip replacements undertaken since the start of 1995. Our review programme began in early 1999 and has generated 3900 assessments. The mean pre-operative scores for primary and revision cases were 40.95 and 40.11, respectively. The mean annual score for primary replacement at between 12 and 84 months ranged between 20.60 and 22.57. A comparison of cross-sectional and longitudinal data showed no significant differences. All post-operative reviews showed a significant improvement (p < or = 0.0001). The 50- to 60-year-old group scored significantly better than the patients over 80 years of age up to 48 months (p < 0.01). A subgroup of 826 National Health Service (NHS) and 397 private patients, treated by the senior author (2292 Oxford assessments), had a higher (i.e. worse) mean pre-operative score for the NHS patients (p < or = 0.001). The private patients scored better than the NHS group up to 84 months (p < 0.05). Patients treated by a surgeon performing more than 100 replacements each year had a significantly better outcome up to five years than those operated on by surgeons performing fewer than 20 replacements each year. The age of the patients at the time of operation, and their pre-operative level of disability, have both been identified as affecting the long-term outcome. Awareness of the influence of these factors should assist surgeons to provide balanced advice.

Gitelman's syndrome: report of a 19-year old woman with intractable hypomagnesemia and hypokalemia, and a review of the syndrome.

A case of refractory hypomagnesemia associated with hypokalemic alkalosis and hypocalciuria (Gitelman's syndrome) is described. The genetic mutations discovered to cause the hypokalemic alkalotic syndromes are described (the thiazide-sensitive sodium chloride co-transporter gene or TSC mutations in Gitelman's syndrome, and the sodium-potassium-chloride co-transporter gene or NKCC2 mutations in Bartter's syndrome). The molecular, electrolyte, and volume abnormalities are described, and the implications for diagnosis, therapy, and future research discussed.

A case of 'reverse' pseudohyperkalemia.

Pseudohyperkalemia is diagnosed when the serum potassium level exceeds the plasma potassium level by 0.4 mmol/l. This is commonly encountered in settings of high leukocyte or platelet counts, since under these conditions, potassium, an intracellular cation, is released in supranormal amounts during the process of clotting. We report an unusual case wherein the reverse was true, i.e., the plasma potassium concentrations was higher than that found in the serum. Heparin, which is known to cause cell lysis, was used as the anti-coagulant in the plasma tubes. We propose that the underlying mechanism in this particular case is a heightened sensitivity to heparin-induced membrane damage in the face of a hematological malignancy.

Mitochondrial genome mutations and kidney disease.

Mutations in the mitochondrial genome have been shown to be responsible for several neuromuscular diseases in humans. In this article, we discuss the molecular genetics of mitochondria, their centrality in cellular energy production, and reasons why their genome is extremely vulnerable to mutation. Mitochondrial DNA (mtDNA) mutations and their classic encephalomyopathic clinical phenotypes are briefly reviewed, and evidence presented that mtDNA mutations also present primarily as kidney diseases. Research trends in the field are discussed. Suggestions are made regarding future work, the clinical implications thereof, and potential therapeutic utility accruing from these advances.

Using tracers to link health services to training through evaluation.

The tracer concept was applied to evaluate the delivery of family health care and the training of family health workers. A retrospective evaluation permitted linking the products of care to process, input and context, by isolating and analysing potential factors contributing to a limited number of representative concerns. Contributory learning deficiencies identified in health workers, one input to health care as well as a product of training, enabled the evaluation of training programmes to be focused on related segments of the courses. The latter were evaluated through a pathway analysis which followed the same deficiency model as the evaluation of health care. Links were thus established between the traditionally compartmentalized training and service sectors in health.