Clostridium infection in a knee extensor mechanism allograft: case report and review

An unusual case of Clostridium perfringens infection after an allograft reconstruction of an extensor mechanism in a multiply revised total knee arthroplasty is reported. The case occurred in an elderly patient with an underlying bleeding dyscrasia who had previously undergone two revision total knee arthroplasties. The patient was treated by open irrigation, debridement, removal of allograft and prosthesis, intravenous antibiotics, and implantation of an antibiotic impregnated cement spacer utilizing an intramedullary rod.     

Academic Portfolio in the Digital Era: Organizing and Maintaining a Portfolio Using Reference Managers

The academic portfolio has become an integral part of the promotions process. Creating and maintaining an academic portfolio in paper-based or web-based formats can be a cumbersome and time-consuming task. In this article, we describe an alternative way to efficiently organize an academic portfolio using a reference manager software, and discuss some of the afforded advantages. The reference manager software Papers (Mekentosj, Amsterdam, The Netherlands) was used to create an academic portfolio. The article outlines the key steps in creating and maintaining a digital academic portfolio. Using reference manager software (Papers), we created an academic portfolio that allows the user to digitally organize clinical, teaching, and research accomplishments in an indexed library enabling efficient updating, rapid retrieval, and easy sharing. To our knowledge, this is the first digital portfolio of its kind.     

Cellular and protein changes in bronchial lavage fluid after late asthmatic reaction in patients with red cedar asthma

To investigate the sequence of cellular and protein changes after a late asthmatic reaction (LAR), bronchial lavage was carried out in 44 patients with red cedar asthma at different time intervals after bronchial challenge with plicatic acid. The results were compared to five patients with red cedar asthma who became asymptomatic after removal from exposure to red cedar for more than 2 months and 31 healthy subjects without asthma. The LAR was found to be associated with an increase in eosinophils in the lavage fluid, an increase in sloughing of bronchial epithelial cells, and an increase in degenerated cells consisting mainly of degenerated epithelial cells and alveolar macrophages. There was an increase in vascular permeability as reflected by an increase in albumin in the lavage fluid. Although there was a slight but significant increase in neutrophils 48 hours after bronchial challenge, neutrophil infiltration was not a prominent feature earlier. The potential role of loss of epithelial cells to account for an increase in nonspecific bronchial hyperresponsiveness after an LAR was discussed.     

Long-term posttreatment functioning among patients with unipolar depression: an integrative model

This study tested an integrative structural equation model of posttreatment functioning among 165 depressed patients followed for an average of 9 years after the end of an episode of treatment. The model examined (a) the link between life change and psychosocial resource change and (b) the role of resource change in mediating the relationship between life change and change in depression. An increase in the preponderance of negative over positive life events was associated with a decline in resources and an increase in depressive symptoms. A decline in resources was associated with an increase in depressive symptoms. The association between changes in events and depressive symptoms was completely mediated through resource change. These findings indicate that life stressors contribute to posttreatment depression through an erosion of personal and social resources.     

A serendipitous isolate of Histoplasma capsulatum

This is a report of an unexpected laboratory diagnosis of Histoplasma capsulatum. The fungus was isolated from an acute cellulitic lesion on the forearm of an elderly male patient with a functioning renal transplant. The patient resides within the environs of Brisbane and has not travelled outside Australia. We consider the isolation of H. capsulatum from a rare site in a patient resident in a non-endemic area indicative of a latent opportunistic infection in an immunocompromised patient.     

The x-ray light valve: a low-cost, digital radiographic imaging system--spatial resolution

An x-ray light valve (XLV) coupled with an optical scanner has the potential to meet the need for a low-cost, high quality digital imaging system for general radiography. The XLV/scanner concept combines three well-established, and hence, low-cost technologies: An amorphous selenium (a-Se) layer as an x-ray-to-charge transducer, a liquid crystal (LC) cell as an analog display, and an optical scanner for image digitization. The XLV consists of an a-Se layer and LC cell in a sandwich structure which produces an optical image in the LC layer upon x-ray exposure. The XLV/scanner system consists of an XLV in combination with an optical scanner for image readout. Here, the effect of each component on the spatial resolution of an XLV/scanner system is investigated. A theoretical model of spatial resolution of an XLV is presented based on calculations of the modulation transfer function (MTF) for a-Se and a LC cell. From these component MTFs, the theoretical MTF of the XLV is derived. The model was validated by experiments on a prototype XLV/scanner system. The MTF of the scanner alone was obtained by scanning an optical test target and the MTF of the XLV/scanner system was measured using x rays. From the measured MTF of the scanner, the theoretical MTF of the XLV/scanner system was established and compared with the experimental results. Good general agreement exists between experimental and theoretical results in the frequency range of interest for general radiography, although the theoretical curves slightly overstate the measured MTFs. The experimental MTF of the XLV was compared with the MTF of two clinical systems and was shown to have the capability to exceed the resolution of flat-panel detectors. From this, the authors can conclude that the XLV has an adequate resolution for general radiography. The XLV/scanner also has the potential to eliminate aliasing while maintaining a MTF that exceeds that of a flat-panel imager.     

Using early clinical experiences to integrate quality-improvement learning into medical education.

Health care providers are delivering care in an increasingly complex environment; this requires that providers develop new competencies to better understand their work and to design changes that can help them succeed. Recognizing these new educational requirements, Dartmouth Medical School created a model two-pronged program for teaching quality improvement to its medical students. The goal of the program is to provide students with an active learning experience as well as an education in the theory and application of continuous quality improvement. The program includes two educational experiences: one curriculum is for all medical students and the other is for selected, highly motivated students. The first curriculum is incorporated in Dartmouth's required "On Doctoring" course, in which students spend time with community-based physician preceptors. The quality-improvement curriculum is designed around an improvement project developed at the students' preceptor sites. The second curriculum for students with a special interest in quality improvement is offered as an elective summer program between the first and second years of medical school. Working in groups of two, students identify an area for improvement within a preceptor's practice, assist the practice in articulating an improvement plan, help implement that plan, and write up their experiences. The authors describe the two curricula, factors associated with their successful implementation, and lessons learned.     

Systemic cell-mediated reactions in vivo. Effect of the interaction of circulating antigen with sensitized lymphocytes on glomeruli and pulmonary alveoli

The effects of systemic cell-mediated hypersensitivity reactions on glomeruli and lungs were investigated in rats. The animals were given an intravenous injection of antigen 7 days after sensitization or were given an intravenous injection of lymph node cells from sensitized syngeneic donors 1 day after antigen injection. Control animals were given an irrelevant antigen or saline. All animals received three injections of 3H-thymidine during the course of the experiments. The animals were sacrificed 2 or 3 days after antigen injection. Autoradiographs of renal and pulmonary tissue showed significantly more labeled mononuclear cells in glomeruli and pulmonary alveolar walls in the experimental groups than in the control groups. Immunofluorescence studies did not reveal antigen, rat IgG, or C3 in glomeruli. The results indicate that systemic cell-mediated reactions can lead to an accumulation of mononuclear cells in glomeruli and lungs, an effect that may contribute to tissue injury.     

In vivo evaluation of a dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to implantable medical devices

The purpose of this research effort was to evaluate in vivo a newly developed dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to an implanted device, in this case a biosensor. The microspheres were prepared using an oil/water (O/W) emulsion technique. The microsphere system was composed of drug-loaded microspheres (including newly formulated and predegraded microspheres) and free dexamethasone. The combination of the drug and drug-loaded microspheres provided burst release of dexamethasone followed by continuous release from days 2-14. Continuous release to at least 30 days was achieved by mixing predegraded and newly formulated microspheres. The ability of our mixed microsphere system to control tissue reactions to an implant then was tested in vivo using cotton thread sutures to induce inflammation subcutaneously in Sprague-Dawley rats. Two different in vivo studies were performed, the first to find the dosage level of dexamethasone that effectively would suppress the acute inflammatory reaction and the second to show how effective the dexamethasone delivered by PLGA microspheres was in suppressing chronic inflammatory response to an implant. The first in vivo study showed that 0.1 to 0.8 mg of dexamethasone at the site minimized the acute inflammatory reaction. The second in vivo study showed that our mixed microsphere system suppressed the inflammatory response to an implanted suture for at least 1 month. This study has proven the viability of microsphere delivery of an anti-inflammatory to control the inflammatory reaction at an implant site.     

E.M.G. operated electronic artificial-leg controller

The paper deals with an e.m.g.-operated prosthesis controller for locking and unlocking of the knee joint in an artificial leg for an above-knee amputee. The controller is highly reliable in operation, uses less man-prosthesis interface and has a low power consumption.     

The iron uptake mechanisms of enteropathogenic Escherichia coli: the use of haem and haemoglobin during growth in an iron-limited environment.

The iron uptake mechanisms of enteropathogenic Escherichia coli (EPEC) were examined and compared with those of control E. coli strains. The incidence of aerobactin production was similar (39% and 37% respectively) in the two groups. The quantities of enterochelin produced by aerobactin-negative EPEC and control strains were similar, as were the quantities of enterochelin produced by aerobactin-positive EPEC and control strains. The ability to use haem or haemoglobin as an iron source in an iron-restricted environment was found in 80.4% and 60.8% of EPEC strains respectively, and in 76.6% and 56.6% of control E. coli strains. The ability of E. coli strains to use these compounds was not related to the production of enterochelin or aerobactin or to the production of haemolysins, and may be an important characteristic of bowel organisms. When growing in an iron-limited environment, the iron contained in haemoglobin was used in preference to ovotransferrin-bound iron. During periods of haemoglobin-stimulated growth, the enterochelin uptake system was shown to be fully expressed and may be involved in transport of haemoglobin-derived iron into the cell. Uptake of ovotransferrin-bound iron took place immediately upon exhaustion of haemoglobin-derived iron. The ability to use iron derived from haem compounds represents an alternative iron uptake mechanism for organisms growing in an iron-limited environment and allows greater flexibility during growth in vivo.     

The Influence of an Antimicrobial Peripherally Inserted Central Catheter on Central Line-Associated Bloodstream Infections in a Hospital Environment

BackgroundFederal agencies such as the Centers for Disease Control and Prevention have mandated reduction of hospital-acquired infections and recommended the use of antimicrobial catheters in clinical settings where central line-associated bloodstream infection (CLABSI) rates have remained high. The Infusion Nurses Society also recommends antimicrobial catheters for specific patient populations. At a California hospital, evidence-based infection prevention strategies for CLABSI prevention had been in effect for several years, but the CLABSI rate remained at an unacceptable level. For this reason, the effect of an antimicrobial peripherally inserted central catheter (PICC) on the incidence of CLABSI was studied.MethodsA quasiexperimental design was used with concurrent data collection on patients in an intervention group who received an antimicrobial PICC. Retrospective data were collected for patients in a nonintervention group who received nonantimicrobial PICCs the previous year.ResultsThe 257 patients in the nonintervention group experienced 8 CLABSIs with an infection rate of 4.18/1,000 line days. The 260 subjects in the intervention group experienced 1 CLABSI with an infection rate of 0.47/1,000 line days. The decrease in the number of infections per 1,000 line days for the intervention group was statistically significant.ConclusionsThe use of an antimicrobial PICC in conjunction with current infection prevention practices resulted in a statistically significant decrease in infection rate, which supports the recommendation for continued use of antimicrobial catheters. Treatment cost savings, which overcame the higher initial cost for the devices, were found to be an additional benefit of using antimicrobial catheters.     

Extracellular GABA in the medial hypothalamus is increased following hypocretin-1 administration

AIM: Hypocretin 1 is an hypothalamic neuropeptide that induces an increase in food intake when administered into the cerebral lateral ventricle. As it is well known that the medial hypothalamus (MH) is involved in the feeding behaviour also through GABAergic circuits, the aim of this experiment was to investigate the effect of an hypocretin 1 intracerebroventricular (icv) injection on the extracellular levels of GABA in the MH. METHODS: GABA levels in the MH were evaluated in six rats by microdialysis and high performance liquid chromatography-electrochemical detection 30 min before and every 30 min for an over all period of 6 h after an icv injection of hypocretin 1. The same procedure was used in another group of six rats but saline was injected into the lateral ventricle as control. RESULTS: The results show that extracellular GABA increases in the MH after the injection of hypocretin 1 at 60 min and at 3 h after the injection. CONCLUSION: This finding suggests a possible mechanism by which hypocretin 1 should induce hyperphagia in the first hour after injection. As it is already known that the inhibition of the MH by injection of GABA causes an increase of food intake, it is possible that hypocretin 1 causes an increase in food intake by increasing the GABA release in the MH. The lack of an increase in the GABA level after the fourth hour is consistent with the lack of an increase in food intake at this time, as we observed in previous experiments. The finding of a biphasic increase in the GABA level, at 60 min and at 3 h, was unexpected and should be further investigated.     

Clinical evaluation of the air removal characteristics of an oxygenator with integrated arterial filter in a minimized extracorporeal circuit

The use of minimized extracorporeal circuits (MECC) in cardiac surgery is an important measure to increase the biocompatibility of cardiopulmonary bypass during coronary artery bypass grafting (CABG). These circuits eliminate volume storage reservoirs and bubble traps to minimize the circuit. However, the reduction in volume may increase the risk of gaseous microemboli (GME). The MECC system as used by our group consists of a venous bubble trap, centrifugal pump, and an oxygenator. To further reduce the risk of introducing GME, an oxygenator with an integrated arterial filter was developed based on the concept of minimal volume and foreign surface. We studied the air removal characteristics of this oxygenator with and without integrated arterial filter. The quantity and volume of GME were measured with precision at both the inlet and outlet of the devices. Our results showed that integration of an arterial filter into this oxygenator increased GME reducing capacity from 69.2% to 92%. Moreover, we were able to obtain data on the impact of an arterial filter on the exact size-distribution of GME entering the arterial line. The present study demonstrates that an MECC system and oxygenator with integrated arterial filter significantly reduces the volume and size of GME. The use of an integrated arterial filter in an MECC system may protect the patient from the deleterious effects of CPB and may further improve patient safety.     

A universal air-bubble detector for infusion pumps

A universal air-bubble detector has been developed for use with drip-controlled infusion pumps. Variations in the peak intensity of modulated infra-red radiation transmitted through the infusion line are used to detect the passage of an air gap or bubble. The device is unique in that bubbles in clear and opaque fluids are detected in most of the standard solution administration sets. The bubble detector is small and light and is an inexpensive way of upgrading an infusion pump to provide an air-in-line alarm facility.     

Demonstration of an anomalous connection between the left coronary artery and the pulmonary artery using a multislice CT 64

In this article, we describe two cases of anomalous connection of the left coronary artery. The first case is an infant of 4 years with an anomalous origin of the left anterior descending (LAD) artery and the diagonal branches and a circumflex artery which originated from the pulmonary artery. The second case is an adult of 50 years with the coronary artery originating from the pulmonary artery. Anomalous origin of the left coronary artery from the pulmonary artery is an uncommon congenital cardiac anomaly with an incidence of 0.25% among all congenital heart defects (Parale and Pawar [2006], J Assoc Physicians India 54:397-399). The originality of this communication consists in the use of a multislice CT scanner as a support for the angiography. The result is an original image with three dimensional details; in the case of the infant, it was determinant in the choice of the surgical approach.     

Self-calibrating interference refractometer using a linear photodiode array for anaesthetic gas analysis

The laboratory standard for measurement of gas concentrations in binary mixtures is the manually operated interfence refractometer. We describe an automatic interference refractometer for theatre use incorporating a linear photodiode array and using digital electronics for signal analysis. The support system performs automatic self-calibration, samples gases from an anaesthetic machine, feeds them to the refractometer and presents information on gas concentrations and possible alarm conditions to the anaesthetist. The instrument may be incorporated into a new anaesthetic machine or may be an addition to an existing one. The instrument may also be applied in other fields where concentrations of known gases need to be monitored automatically.     

Imiquimod 5% cream: a new treatment for Bowen's disease

Bowen's disease (BD) is a squamous cell carcinoma in situ. Recent studies suggest that human papilloma virus plays an important role in the development of BD. We investigated whether imiquimod 5%, a topical immune response modifier, is an effective treatment for BD in five immunocompetent patients. The lesions were one genital and four extragenital. The frequency of application varied from three times weekly up to twice daily, and treatment duration ranged from 8-24 weeks. Four patients achieved clinical and histological cure. The patient with the genital lesion gained an important reduction in size and infiltration, which enabled surgical removal of the remaining lesion with good functional and cosmetic result. Our results suggest that topical imiquimod 5% is an effective treatment for BD through its viral and antitumor effects.     

Alpha event-related desynchronization preceding a go/no-go task: a high-resolution EEG study

The authors delineated the time evolution of alpha event-related desynchronization over human frontal, parietal, and primary sensorimotor areas during the expectancy of a go/no-go task. The main issue under investigation was whether anticipatory processes impinged upon cortical areas in sequential or parallel mode. Compared with the control condition, in the experimental condition there was an Alpha 1 desynchronization over the central midline, an Alpha 2 desynchronization increasing over primary sensorimotor areas, and an Alpha 3 desynchronization increasing in parallel over bilateral primary sensorimotor areas. These processes had different temporal features. Results disclose an anticipatory activity of central midline areas and primary sensorimotor areas in both parallel and sequential modes. This reflects an adaptive, energy-consuming strategy rather than an economic waiting for the go stimulus.     

Inversions in the factor VIII gene: improvement of carrier detection and prenatal diagnosis in Dutch haemophilia A families.

Haemophilia A is an X linked bleeding disorder caused by a heterogeneous spectrum of mutations in the factor VIII gene. It has recently been reported that about 50% of severe haemophilia A cases are the result of an iversion in the factor VIII gene. The inversion results from homologous recombination between the A gene located in intron 22 of the FVIII gene and one of the two distal A genes, thus disrupting the coding sequence of the factor VIII gene. The inversion can be detected by conventional Southern blotting and hybridisation techniques. Here we present an analysis of 177 unrelated Dutch haemophilia A cases for the presence of an inversion. In 57% of the patients with severe disease an inversion was found and also in at least one of the 26 patients with moderately severe disease. The majority of inversions (85%) involved the most distal A gene, while in a minority (15%) the more proximal A gene was involved. We show that direct mutation detection greatly improves the assessment of carrier status and prenatal diagnosis for haemophilia A, especially in families with an isolated patient. The inversion is predominantly of grandpaternal origin.