Bone Wax Is Effective in Reducing Blood Loss After Total Knee Arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is associated with major blood loss and blood transfusion is often required. This study aimed to evaluate the efficacy of bone wax in reducing blood loss and transfusion rates after TKA. METHODS: A prospective randomized controlled study that included 100 patients undergoing primary unilateral TKA with cement was conducted in a tertiary center between March 2014 and June 2014. The bone wax group received 2.5 g of bone wax, applied onto the uncovered bone around the prostheses and the nail holes before the tourniquet was released, whereas the control group had hemostasis achieved using electrocautery only. Total blood loss was calculated using the hemoglobin balance method. RESULTS: There were no demographic differences between the 2 groups. The preoperative serum hemoglobin levels were comparable between the 2 groups. The drop in serum hemoglobin levels at 24 h post-TKA was 1.6 ± 0.9 and 2.1 ± 1.1 g/dL in the bone wax and control groups respectively (P = .021), while the drop in serum hemoglobin levels at 72 h post-TKA was 2.7 ± 1.1 and 3.6 ± 1.2 g/dL respectively (P = .013). Total blood loss at 72 h post-TKA was 987.9 and 1183.5 mL for the bone wax and control groups respectively (P = .017). There was no adverse event associated with the use of bone wax at the 3-month follow-up. CONCLUSION: The application of bone wax in TKA was safe and effective for reducing total blood loss and maintaining higher hemoglobin levels.

[Results of measuring neutrons doses and energy spectra inside Russian segment of the International Space Station in experiment "Matryoshka-R" using bubble detectors during the ISS-24-34 missions].

The paper presents the results of calculating the equivalent dose from and energy spectrum of neutrons in the right-hand crewquarters in module Zvezda of the ISS Russian segment. Dose measurements were made in the period between July, 2010 and November, 2012 (ISS Missions 24-34) by research equipment including the bubble dosimeter as part of experiment "Matryoshka-R". Neutron energy spectra in the crewquarters are in good agreement with what has been calculated for the ISS USOS and, earlier, for the MIR orbital station. The neutron dose rate has been found to amount to 196 +/- 23 microSv/d on Zvezda panel-443 (crewquarters) and 179 +/- 16 microSv/d on the "Shielding shutter" surface in the crewquarters.

The differential effects of statins on the risk of developing pancreatic cancer: a case-control study in two centres in the United Kingdom.

INTRODUCTION: There are plausible biological mechanisms for how statins may prevent pancreatic cancer, although the evidence from epidemiological studies in the general population is conflicting. This study aims to clarify whether statins exert their effects in specific sub-groups, namely, gender, smoking status and diabetes. METHODS: A matched case-control study was conducted in patients diagnosed with pancreatic cancer, and a group of dermatology patients of similar ages and gender, diagnosed with basal cell carcinoma. Participants' medical records were reviewed for information on statin use prior to diagnosis. Odds ratios and 95 % CIs for the development of pancreatic cancer were estimated using conditional logistic regression. Subgroup analysis was performed in men, women, smokers and those with type 2 diabetes. RESULTS: Two hundred fifty-two cases (median age 71 years, range 48-73 years, 51 % women) and 504 controls were identified, of which 23 % of cases were regular statin users versus 21 % of controls. In the general study population there was no association between pancreatic cancer and regular statin use (OR 0.82, 95 % CI 0.53-1.23, p = 0.33). However, in male smokers, regular statin use was associated with significantly reduced odds of pancreatic cancer compared to male smokers not prescribed a statin (OR 0.11, 95 % CI 0.01-0.96, p = 0.05). In patients with type 2 diabetes statins use was not associated with reduced odds (OR 0.92, 95 % CI 0.35-2.45, p = 0.80), with no gender effects. CONCLUSIONS: In male smokers, statins may reduce the odds of pancreatic cancer. Statin use should be measured in aetiological studies of pancreatic cancer but analysed in specific sub-groups. Future work should investigate statins as chemopreventative agents in this high risk sub-group.

Portable spectroscopic neutron probe.

Bubble Technology Industries (BTI) has built a revolutionary portable neutron scintillation spectrometer, N-Probe, designed to be used by non-specialists for measurement of low-intensity neutron doses in the mixed field environments often found in nuclear utilities, fuel storage areas, fuel and waste processing operations and military applications. It is compatible with the current generation of BTI MICROSPEC analysers and shares the philosophy of spectral dosimetry with other BTI spectroscopic probes, where the dosimetric quantities are computed from the spectrum using appropriate fluence-dose conversion functions.

Modification of ROSPEC to cover neutrons from thermal to 18 MeV.

Rotating Spectrometer (ROSPEC) is a neutron spectrometer designed to measure neutron energy distributions, and provide accurate neutron dosimetry. It is a completely self-contained unit and measures neutron energy via recoiling protons in gas proportional counters. Each of the four original gas counters is dedicated to a particular neutron energy range dictated by sensitivity to gamma rays at the low energy end of the spectrum and by proton collisions with the counter walls at the high energy end. Introduced originally in 1992, ROSPEC has a proven operational record with a program of continued upgrades. The operating range of the original ROSPEC spans 50 keV-4.5 MeV. The range of the ROSPEC has now been extended down to include epithermal and thermal neutrons by adding two 2 in. (3)He counters. Also, an optional simple scintillation spectrometer was designed to extend the upper limit of ROSPEC up to 18 MeV.

LET dependence of bubble detector response to heavy ions.

A series of experiments have been recently performed at the Heavy Ion Medical Accelerator in Chiba (HIMAC) laboratory to study the response of bubble detectors to high-mass high-energy (HZE) particles. The motivation for this study was to improve our ability to interpret measurements of neutron energy spectra in space. A recent analysis showed that emulsions of light halocarbons display common properties when they are characterised by a quantity called 'reduced superheat'. This quantity evolved from the examination of neutron and gamma responses of many types of detectors. In this study, we describe direct irradiations with N, Ar and Kr charged particles at HIMAC. It was observed that when the linear energy transfer (LET) corresponding to bubble formation was plotted vs. reduced superheat, different curves were obtained for a particular ion for detectors at different temperatures. Different curves were also obtained when data from different ions were plotted. These results confirm that bubble nucleation is not a simple function of particle LET and that an analysis based on track-structure appears warranted.

Characterisation of bubble detectors for aircrew and space radiation exposure.

The Earth's atmosphere acts as a natural radiation shield which protects terrestrial dwellers from the radiation environment encountered in space. In general, the intensity of this radiation field increases with distance from the ground owing to a decrease in the amount of atmospheric shielding. Neutrons form an important component of the radiation field to which the aircrew and spacecrew are exposed. In light of this, the neutron-sensitive bubble detector may be ideal as a portable personal dosemeter at jet altitudes and in space. This paper describes the ground-based characterisation of the bubble detector and the application of the bubble detector for the measurement of aircrew and spacecrew radiation exposure.

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is ∼70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data.

Use of a systematic risk analysis method to improve safety in the production of paediatric parenteral nutrition solutions.

BACKGROUND: Until recently, the preparation of paediatric parenteral nutrition formulations in our institution included re-transcription and manual compounding of the mixture. Although no significant clinical problems have occurred, re-engineering of this high risk activity was undertaken to improve its safety. Several changes have been implemented including new prescription software, direct recording on a server, automatic printing of the labels, and creation of a file used to pilot a BAXA MM 12 automatic compounder. The objectives of this study were to compare the risks associated with the old and new processes, to quantify the improved safety with the new process, and to identify the major residual risks. METHODS: A failure modes, effects, and criticality analysis (FMECA) was performed by a multidisciplinary team. A cause-effect diagram was built, the failure modes were defined, and the criticality index (CI) was determined for each of them on the basis of the likelihood of occurrence, the severity of the potential effect, and the detection probability. The CIs for each failure mode were compared for the old and new processes and the risk reduction was quantified. RESULTS: The sum of the CIs of all 18 identified failure modes was 3415 for the old process and 1397 for the new (reduction of 59%). The new process reduced the CIs of the different failure modes by a mean factor of 7. The CI was smaller with the new process for 15 failure modes, unchanged for two, and slightly increased for one. The greatest reduction (by a factor of 36) concerned re-transcription errors, followed by readability problems (by a factor of 30) and chemical cross contamination (by a factor of 10). The most critical steps in the new process were labelling mistakes (CI 315, maximum 810), failure to detect a dosage or product mistake (CI 288), failure to detect a typing error during the prescription (CI 175), and microbial contamination (CI 126). CONCLUSIONS: Modification of the process resulted in a significant risk reduction as shown by risk analysis. Residual failure opportunities were also quantified, allowing additional actions to be taken to reduce the risk of labelling mistakes. This study illustrates the usefulness of prospective risk analysis methods in healthcare processes. More systematic use of risk analysis is needed to guide continuous safety improvement of high risk activities.

Esophageal carcinoma masquerading as recurrent acute suppurative thyroiditis.

A 61-year-old woman had clinical features of acute suppurative thyroiditis that was recurrent and refractory to antibiotic therapy. The diagnosis of acute suppurative thyroiditis was established by a fine-needle aspiration biopsy procedure, yielding suppurative material from which anaerobic and aerobic bacteria grew. Subsequent investigation with a barium swallow study followed by esophagoscopy and biopsy confirmed extensive esophageal carcinoma with a fistulous tract extending into the perithyroidal region.

Bubble detector characterization for space radiation.

In light of the importance of the neutron contribution to the dose equivalent received by space workers in the near-Earth radiation environment, there is an increasing need for a personal dosimeter that is passive in nature and able to respond to this neutron field in real time. Recent Canadian technology has led to the development of a bubble detector, which is sensitive to neutrons, but insensitive to low linear energy transfer (LET) radiation. By changing the composition of the bubble detector fluid (or "superheat"), the detectors can be fabricated to respond to different types of radiation. This paper describes a preliminary ground-based research effort to better characterize the bubble detectors of different compositions at various charged-particle accelerator facilities, which are capable of simulating the space radiation field.

A Canadian high-energy neutron spectrometry system for measurements in space.

Bubble Technology Industries Inc. (BTI), with the support of the Canadian Space Agency, has finished the construction of the Canadian High-Energy Neutron Spectrometry System (CHENSS). This spectrometer is intended to measure the high energy neutron spectrum (approximately 1-100 MeV) encountered in spacecraft in low earth orbit. CHENSS is designed to fly aboard a US space shuttle and its scientific results should facilitate the prediction of neutron dose to astronauts in space from readings of different types of radiation dosimeters that are being used in various missions.

Response of the bubble detector to neutrons of various energies.

A series of Monte-Carlo simulations has been performed in order to investigate the response of the bubble detector to monoenergetic neutrons of various energies. The work was driven by the need to better understand the energy dependence of the detector for applications in space, where the neutron spectrum has a significant component with energy of >20 MeV. The response to neutrons in the range of a few keV to 500 MeV has been calculated, and good agreement between the simulations and experimental data is demonstrated over the entire energy range.

Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS.

Probability of filtration surgery in patients with open-angle glaucoma.

OBJECTIVE: To investigate the probability of undergoing filtration surgery in either 1 or both eyes in patients in whom open-angle glaucoma was newly diagnosed. METHODS AND DESIGN: A retrospective community-based study of 295 residents of Olmsted County, Minnesota, in whom open-angle glaucoma was newly diagnosed between January 1, 1965, and December 31, 1980, was performed. Kaplan-Meier methods were used to estimate the cumulative probability of undergoing filtration surgery during a 20-year period. RESULTS: At 20 years of follow-up, the Kaplan-Meier cumulative probability of undergoing filtration surgery in at least 1 eye was estimated to be 23% (95% confidence interval, 16%-30%), and in both eyes the estimate was 12% (95% confidence interval, 6%-17%). Patients with optic nerve damage at the time of diagnosis were more likely to undergo surgery than patients with elevated intraocular pressure but no damage (1 eye, 39% vs 15%; both eyes, 27% vs 5%). CONCLUSION: This retrospective study of a white population newly diagnosed as having and treated for open-angle glaucoma indicates that while most patients did not undergo filtration surgery in the course of glaucoma therapy, at least one third of those with glaucomatous damage at the time of diagnosis underwent filtration surgery.

Unwanted radiation produced by leakage neutrons from medical electron accelerators.

Monte Carlo calculations have been made to determine the energy delivered to a phantom by neutrons escaping from the head of a Varian Clinac 35 medical accelerator at an SSD of 1 m. The energy was sorted into two regions: inside and outside a volume defined by a circular beam of area 100 and 600 cm2. For the two beam sizes, the energies outside the treatment volume were 12 and 8.7 g-rad (per photon rad) respectively. Room scattering increased these values by about 20%. These energies are smaller than those delivered by scattered photons by more than ten times.

Unwanted photon and neutron radiation resulting from collimated photon beams interacting with the body of radiotherapy patients.

Monte Carlo calculations have been made to determine the energies delivered by photons and neutrons to the human body irradiated by collimated photon beams. The beams were monoenergetic and ranged from 100 keV to 40 MeV. The energy deposition in the body was sorted into two regions: inside and outside the irradiated volume. Most of the results obtained were for a beam size of 100 cm2 although some calculations were also made to 600 cm2 beams. The effect of beam size on energy deposition in the two regions was investigated for 60Co gamma rays. Graphs are presented which give the integral doses delivered by neutrons and photons to the two regions for therapy beams of various energies. These graphs can be used to calculate the integral doses which are delivered inside and outside the treatment volume for photon spectra from most medical accelerators. Calculations of energy deposition were also made for the spectra from two particular accelerators. These were done using Monte Carlo as well as by simply "folding" the spectra into the results for monoenergetic photons. The results obtained by both methods were in good agreement and indicated that the integral doses deposited outside the treatment volume by neutrons are more than two orders of magnitude smaller than those deposited by scattered photons.

Spectra and dosimetry related to neutron irradiations of the human body.

Neutron spectra at various locations in a phantom, irradiated by collimated beams of 14 MeV neutrons and neutrons from 252 Cf and Po-Be sources, were calculated using the Monte Carlo technique. These spectra give an indication of the distortion in source spectra associated with neutron irradiations of the body for therapeutic and diagnostic purposes. The effect of the spectral distortions on the dose response of several activation and damage track detectors was investigated. Of the dosemeters studied, Np has a dose response most nearly independent (+/-10%) of the spectral changes.

Diagnosing oral diseases that affect the eyes.

Dentists can often help diagnose diseases that affect the eyes. This article discusses the diseases and iatrogenic dental conditions where ophthalmic and oral findings play a key role in diagnosis and treatment.

Space radiation dosimetry using bubble detectors.

Bubble detectors--a new development in radiation detection--has only recently been used for radiation measurements in space. One important characteristic of the bubble detector is that it operates on a phenomenon which bears considerable resemblance to biological response. Recent experimental results from irradiating bubble detectors with high-energy heavy ions point to the need to re-examine the methodology used for assessing space radiation and the relevance of conventional quantities such as dose equivalent for space dosimetry. It may be that biological hazard associated with the intensely ionizing events--associated with nuclear fragmentation but delivering relatively small dose equivalent--may be much more important than that associated with lightly ionizing events which comprise the bulk of the conventional radiation dose equivalent.