Hip offset and leg-length restoration in revision hip arthroplasty with a monoblock, hydroxyapatite-coated stem

AIMS

Restoration of normal hip biomechanics in arthroplasty surgery is important in order to achieve good muscle function and joint stability.

METHODS

In this retrospective cohort study, we examined the postoperative radiographs of 131 femoral revision arthroplasty procedures using a monoblock, fully hydroxyapatite (HA)-coated titanium stem. Femoral offset, modified-global offset and leg length were measured of the operated and contralateral hips.

RESULTS

Femoral offset was restored to ±10 mm in 108 cases (82%), modified-global offset was restored ±10 mm in 93 cases (71%) and leg length was restored to ±10 mm in 102 cases (81%). There were 4 dislocations with a mean follow-up period of 38 months.

CONCLUSIONS

Restoration of hip biomechanics is achievable with a monoblock stem and thus is a viable option in revision hip arthroplasty.

Clinical outcomes and cost analysis of one- versus two-stage bilateral hip arthroplasty. A retrospective study of a single surgeon experience

Purpose:

One in 10 patients presenting for total hip arthroplasty (THA) will have significant osteoarthritis in both hips. In appropriately selected individuals, one-stage bilateral THA is a treatment option. This study aims to compare outcomes of one-stage bilateral THA with two-stage procedure.

Methods:

A retrospective review of a single surgeon series was conducted comparing One-stage bilateral THA (n = 59) with two-stage bilateral THA (n = 50). The primary outcomes were post-operative complication and the Oxford Hip Score. The secondary outcome was a financial analysis.

Results:

Complications were infrequent and comparable between both groups. Oxford hip scores were slightly higher in the one-stage group. One-staged bilateral THA had a lower cost but hospital tariff is higher for two-stage bilateral THA.

Conclusion:

In appropriately selected patients with bilateral hip arthritis, one-stage bilateral THA gives good clinical outcomes. However, the current payment system in the NHS makes two-stage bilateral THA more financially viable to the hospital.

Survivorship and Radiological Analysis of a Monoblock, Hydroxyapatite-Coated Titanium Stem in Revision Hip Arthroplasty

BACKGROUND

We evaluated the survivorship, incidence of complications, radiological subsidence, proximal stress shielding, and patient-reported outcomes of a conservative, monoblock, hydroxyapatite-coated femoral stem.

METHODS

This retrospective cohort study reports on 254 revision hip arthroplasties between January 2006 and June 2016. The mean age of patients was 71 years. The mean length of follow-up was 62 months (range 12-152).

RESULTS

There were 13 stem re-revisions: infection (4), periprosthetic fracture (4), aseptic stem loosening (3), stem fracture (1), and extended trochanteric osteotomy nonunion (1). Kaplan-Meier aseptic stem survivorship was 97.33% (confidence interval 94-100) at 6 years. There were 29 intraoperative fractures. There were 6 cases of subsidence greater than 10 mm; however, none required revision. Ninety-six percent of cases showed no proximal stress shielding. Thigh pain was reported in 3% of cases.

CONCLUSION

This study confirms that this stem provides good survivorship at 6 years, acceptable complication rates, adequate proximal bone loading, low incidences of thigh pain, and reliable clinical performance in revision hip arthroplasty.

KEY MESSAGE

A monoblock, fully hydroxyapatite-coated titanium stem is reliable in revision arthroplasty with mild-moderate femur deficiencies.

The clinical relevance of sound changes produced during cementless hip arthroplasty: a correctly sized femoral broach creates a distinctive pattern of audio frequencies directly related to bone geometry

AIMS

Cementless femoral stems must be correctly sized and well-seated to obtain satisfactory biological fixation. The change in sound that occurs during impaction of the femoral broach is said to indicate good fit, but this has not been widely studied. We set out to find whether the presence or absence of these sound changes could predict correct sizing.

PATIENTS AND METHODS

We recorded the sound generated during femoral broaching for 105 cementless total hip arthroplasties using the Corail stem. Four cases were excluded, leaving 101 recordings for analysis. There were 36 male patients and 65 female patients, with a mean age of 69.9 years (sd 12.3) and median body mass index (BMI) of 29 kg/m ² (interquartile range (IQR) 26 to 32). The recordings were analyzed to identify the frequencies of the sounds produced during impaction of the femoral broach.

RESULTS

The emergence of a low-frequency band of sound in the 1 kHz range, during the final femoral broaching, was a strong predictor of a well-sized implant stem. The frequency was related to femoral length, supporting our hypothesis that the sound arose from the bone itself.

CONCLUSION

The low-frequency sound generated during femoral broaching can be monitored spectrographically, its frequency can be predicted from femoral length, and it is a good predictor of appropriate stem sizing.

Risk of subsidence and peri-prosthetic fractures using collared hydroxyapatite-coated stem for hip arthroplasty in the elderly

INTRODUCTION

Subsidence has been noted with both cemented and uncemented stems in hip arthroplasty. On most occasions, it's minimal (i.e. less than 2 mm) and stabilises at 1 year. However, when its progressive and significant, it causes loss of length and horizontal offset, and when symptomatic warrants a revision.

MATERIALS AND METHODS

A retrospective radiological review of the patient database was carried out to identify all patients with age ≥ 70 years who underwent elective hip arthroplasty using uncemented HA coated collared stem and had radiographs at 1 year follow up. A total of 176 patients were identified from January 2009 to June 2010. 2 independent investigators classified the proximal femur based on Dorr type and calculated the subsidence based on Engh and Massin method of calculating the distance between the tip of greater trochanter and shoulder of the prosthesis.

RESULTS

7 patients (4 Bs, 2 As, 1 C) had a subsidence of ≥ 2 mm (2-3.2 mm) at 1 year. None of them was symptomatic. 1 of them was secondary to a missed calcar crack and continued to subside for 9 mm before it stabilised on the lesser trochanter at 4 years follow up. There were Dorr 22 (12.5%) type A, 147(83.5%) type B and 7(4%) type C. The mean age was 77.4 years (70-91 years) and male: female ratio was 7:15. 3 patients had an intraoperative calcar crack requiring cabling. All were mobilised full weight-bearing postoperatively, and none had a subsidence of >2 mm at 1 year follow-up.

DISCUSSION

Our subgroup analysis identified that subsidence can happen when the collar is "non-functional" and the initial press fit of the stem wasn't achieved. It can also occur in an event of calcar crack, which is missed intraoperatively. In cases of calcar crack which went on to have to cable during the primary procedure, it neither changed the post-operative rehabilitation nor did it show an increased risk of subsidence.

CONCLUSION

A fully hydroxyapatite (HA) coated collared stem, when used in elderly age group for elective THR, has only 2% risk of intraoperative periprosthetic fracture. There's a 4% risk of radiologically significant subsidence (i.e. ≥2 mm), however, it has not proven to be clinically significant in our study. Dorr canal type had no bearing on either risk of periprosthetic fracture or subsidence. Collared stems did not have a statistically significant difference in risk of subsidence and peri-prosthetic fracture in comparison to un-collared stem, although there was a non-significant trend in favour of collar use.

The Sensory Striatum Is Permanently Impaired by Transient Developmental Deprivation

Corticostriatal circuits play a fundamental role in regulating many behaviors, and their dysfunction is associated with many neurological disorders. In contrast, sensory disorders, like hearing loss (HL), are commonly linked with processing deficits at or below the level of the auditory cortex (ACx). However, HL can be accompanied by non-sensory deficits, such as learning delays, suggesting the involvement of regions downstream of ACx. Here, we show that transient developmental HL differentially affected the ACx and its downstream target, the sensory striatum. Following HL, both juvenile ACx layer 5 and striatal neurons displayed an excitatory-inhibitory imbalance and lower firing rates. After hearing was restored, adult ACx neurons recovered balanced excitatory-inhibitory synaptic gain and control-like firing rates, but striatal neuron synapses and firing properties did not recover. Thus, a brief period of abnormal cortical activity may induce cellular impairments that persist into adulthood and contribute to neurological disorders that are striatal in origin.

First Searches for Axions and Axionlike Particles with the LUX Experiment

The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons g_{Ae} is tested using data collected in 2013 with an exposure totaling 95 live days ×118  kg. A double-sided, profile likelihood ratio statistic test excludes g_{Ae} larger than 3.5×10^{-12} (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12  eV/c^{2}, while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6  eV/c^{2} are excluded. For galactic axionlike particles, values of g_{Ae} larger than 4.2×10^{-13} are excluded for particle masses in the range 1-16  keV/c^{2}. These are the most stringent constraints to date for these interactions.

Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5  kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=1.6×10^{-41}  cm^{2} (σ_{p}=5×10^{-40}  cm^{2}) at 35  GeV c^{-2}, almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

Results from a Search for Dark Matter in the Complete LUX Exposure

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4}  kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50  GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46}  cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46}  cm^{2} at 50  GeV c^{-2}.

Trends in health care utilization and costs attributable to hepatocellular carcinoma, 2002-2009: a population-based cohort study

BACKGROUND

The incidence of hepatocellular carcinoma (hcc) and the complexity of its diagnosis and treatment are increasing. We estimated trends in net health care utilization, costs of care attributable to hcc in Ontario, and rate ratios of resource use at various stages of care.

METHODS

This population-based retrospective cohort study identified hcc patients and non-cancer control subjects, and health care resource utilization between 2002 and 2009. Generalized estimating equations were then used to estimate net health care utilization (hcc patients vs. the matched control subjects) and net costs of care attributable to hcc. Generalized linear models were used to analyze rate ratios of resource use.

RESULTS

We identified 2832 hcc patients and 2808 matched control subjects. In comparison with the control subjects, hcc patients generally used a greater number of health care services. Overall, the mean net cost of care per 30 patient-days (2013 Canadian dollars) attributable to outpatient visits and hospitalizations was highest in the pre-diagnosis (1 year before diagnosis), initial (1st year after diagnosis), and end-of-life (last 6 months before death, short-term survivors) phases. Mean net homecare costs were highest in the end-of-life phase (long-term survivors). In the end-of-life phase (short-term survivors), mean net costs attributable to outpatient visits and total services significantly increased to $14,220 from $1,547 and to $33,121 from $14,450 (2008-2009 and 2002-2003 respectively).

CONCLUSIONS

In hcc, our study found increasing resource use and net costs of care, particularly in the end-of-life phase among short-term survivors. Our findings offer a basis for resource allocation decisions in the area of cancer prevention and control.

Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment

We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4×10^{4}  kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=9.4×10^{-41}  cm^{2} (σ_{p}=2.9×10^{-39}  cm^{2}) at 33  GeV/c^{2}. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4}  kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4  GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33  GeV c^{-2} WIMP mass.

Will Large DSO-Managed Group Practices Be the Predominant Setting for Oral Health Care by 2025? Two Viewpoints: Viewpoint 1: Large DSO-Managed Group Practices Will Be the Setting in Which the Majority of Oral Health Care Is Delivered by 2025 and Viewpoint 2: Increases in DSO-Managed Group Practices Will Be Offset by Models Allowing Dentists to Retain the Independence and Freedom of a Traditional Practice

This Point/Counterpoint article discusses the transformation of dental practice from the traditional solo/small-group (partnership) model of the 1900s to large Dental Support Organizations (DSO) that support affiliated dental practices by providing nonclinical functions such as, but not limited to, accounting, human resources, marketing, and legal and practice management. Many feel that DSO-managed group practices (DMGPs) with employed providers will become the setting in which the majority of oral health care will be delivered in the future. Viewpoint 1 asserts that the traditional dental practice patterns of the past are shifting as many younger dentists gravitate toward employed positions in large group practices or the public sector. Although educational debt is relevant in predicting graduates' practice choices, other variables such as gender, race, and work-life balance play critical roles as well. Societal characteristics demonstrated by aging Gen Xers and those in the Millennial generation blend seamlessly with the opportunities DMGPs offer their employees. Viewpoint 2 contends the traditional model of dental care delivery-allowing entrepreneurial practitioners to make decisions in an autonomous setting-is changing but not to the degree nor as rapidly as Viewpoint 1 professes. Millennials entering the dental profession, with characteristics universally attributed to their generation, see value in the independence and flexibility that a traditional practice allows. Although DMGPs provide dentists one option for practice, several alternative delivery models offer current dentists and future dental school graduates many of the advantages of DMGPs while allowing them to maintain the independence and freedom a traditional practice provides.

Spiteful interactions between sympatric natural isolates of Xenorhabdus bovienii benefit kin and reduce virulence

Spite occurs when an individual harms itself in the act of harming others. Spiteful behaviour may be more pervasive in nature than commonly thought. One of the clearest examples of spite is the costly production and release of bacteriocins, antimicrobial toxins noted for their ability to kill conspecifics. A key question is to what extent these toxins provide a fitness advantage to kin of the producer cell, especially in natural communities. Additionally, when bacteria are involved in parasitic relationships, spiteful interactions are predicted to lower bacterial densities within a host, causing a reduction in parasite-induced virulence. Using five sympatric, field-collected genotypes of the insect pathogen Xenorhabdus bovienii, we experimentally demonstrate that bacteriocin production benefits kin within the host, and that it slows the mortality rate of the host. These results confirm that spite among naturally coexisting bacterial clones can be a successful kin-selected strategy that has emergent effects on virulence.

Assessing dental students' competence: best practice recommendations in the performance assessment literature and investigation of current practices in predoctoral dental education

In this article, the Task Force on Student Outcomes Assessment of the American Dental Education Association's Commission on Change and Innovation in Dental Education describes the current status of student outcomes assessment in U.S. dental education. This review is divided into six sections. The first summarizes the literature on assessment of dental students' performance. Section two discusses catalysts, with a focus on problem-based learning, for development of new assessment methods, while the third section presents several resources and guides that can be used to inform selection of assessment techniques for various domains of competence. The fourth section describes the methodology and results of a 2008 survey of current assessment practices in U.S. dental schools. In the fifth section, findings from this survey are discussed within the context of competency-based education, the educational model for the predoctoral curriculum endorsed by the American Dental Education Association and prescribed by the Commission on Dental Accreditation. The article concludes with a summary of assessments recommended as optimal strategies to measure three components of professional competence based on the triangulation model. The survey of assessment practices in predoctoral education was completed by 931 course directors, representing 45 percent of course directors nationwide, from fifty-three of the fifty-six U.S. dental schools. Survey findings indicate that five traditional mainstays of student performance evaluation-multiple-choice testing, lab practicals, daily grades, clinical competency exams, and procedural requirements-still comprise the primary assessment tools in dental education. The survey revealed that a group of newer assessment techniques, although frequently identified as best practices in the literature and commonly used in other areas of health professions education, are rarely employed in predoctoral dental education.

Does faculty development enhance teaching effectiveness?

Academic dentists and members of the practice community have been hearing, for more than a decade, that our educational system is in trouble and that the profession has lost its vision and may be wavering in the achievement of its goals. A core of consistently recommended reforms has framed the discussion of future directions for dental education, but as yet, most schools report little movement toward implementation of these reforms in spite of persistent advocacy. Provision of faculty development related to teaching and assessment strategies is widely perceived to be the essential ingredient in efforts to introduce new curricular approaches and modify the educational environment in academic dentistry. Analyses of the outcomes of efforts to revise health professions curricula have identified the availability and effectiveness of faculty development as a predictor of the success or failure of reform initiatives. This article will address faculty development for purposes of enhancing teaching effectiveness and preparing instructors for potential new roles associated with curriculum changes. Its overall purpose is to provide information and insights about faculty development that may be useful to dental schools in designing professional growth opportunities for their faculty. Seven questions are addressed: 1) What is faculty development? 2) How is faculty development accomplished? 3) Why is faculty development particularly important in dental education? 4) What happens when faculty development does not accompany educational reform? 5) Why are teaching attitudes and behaviors so difficult to change? 6) What outcomes can be expected from faculty development? and 7) What does the available evidence tell us about the design of faculty development programs? Evidence from systematic reviews pertaining to the teaching of evidence-based dentistry, strategies for continuing professional education, and the Best Evidence in Medical Education review of faculty development outcomes are presented to answer this question: does faculty development enhance teaching effectiveness? Characteristics consistently associated with effective faculty development are described.

The dental education environment

The second in a series of perspectives from the ADEA Commission on Change and Innovation in Dental Education (CCI), this article presents the CCI's view of the dental education environment necessary for effective change. The article states that the CCI's purpose is related to leading and building consensus in the dental community to foster a continuous process of innovative change in the education of general dentists. Principles proposed by CCI to shape the dental education environment are described; these are critical thinking, lifelong learning, humanistic environment, scientific discovery and integration of knowledge, evidence-based oral health care, assessment, faculty development, and the health care team. The article also describes influences external to the academic dental institutions that are important for change and argues that meaningful and long-lasting change must be systemic in nature. The CCI is ADEA's primary means to engage all stakeholders for the purpose of educating lifelong learners to provide evidence-based care to meet the needs of society.

Educational strategies associated with development of problem-solving, critical thinking, and self-directed learning

This article was developed for the Commission on Change and Innovation in Dental Education (CCI), established by the American Dental Education Association. CCI was created because numerous organizations within organized dentistry and the educational community have initiated studies or proposed modifications to the process of dental education, often working to achieve positive and desirable goals but without coordination or communication. The fundamental mission of CCI is to serve as a focal meeting place where dental educators and administrators, representatives from organized dentistry, the dental licensure community, the Commission on Dental Accreditation, the ADA Council on Dental Education and Licensure, and the Joint Commission on National Dental Examinations can meet and coordinate efforts to improve dental education and the nation's oral health. One of the objectives of the CCI is to provide guidance to dental schools related to curriculum design. In pursuit of that objective, this article summarizes the evidence related to this question: What are educational best practices for helping dental students acquire the capacity to function as an entry-level general dentist or to be a better candidate to begin advanced studies? Three issues are addressed, with special emphasis on the third: 1) What constitutes expertise, and when does an individual become an expert? 2) What are the differences between novice and expert thinking? and 3) What educational best practices can help our students acquire mental capacities associated with expert function, including critical thinking and self-directed learning? The purpose of this review is to provide a benchmark that faculty and academic planners can use to assess the degree to which their curricula include learning experiences associated with development of problem-solving, critical thinking, self-directed learning, and other cognitive skills necessary for dental school graduates to ultimately become expert performers as they develop professionally in the years after graduation.

The case for change in dental education

This article introduces a series of white papers developed by the ADEA Commission on Change and Innovation (CCI) to explore the case for change in dental education. This preamble to the series argues that there is a compelling need for rethinking the approach to dental education in the United States. Three issues facing dental education are explored: 1) the challenging financial environment of higher education, making dental schools very expensive and tuition-intensive for universities to operate and producing high debt levels for students that limit access to education and restrict career choices; 2) the profession's apparent loss of vision for taking care of the oral health needs of all components of society and the resultant potential for marginalization of dentistry as a specialized health care service available only to the affluent; and 3) the nature of dental school education itself, which has been described as convoluted, expensive, and often deeply dissatisfying to its students.

Neutrophil maturation and activation determine anatomic site of clearance from circulation

The long-term disposition of circulating neutrophils and the site of disappearance from circulation remain unclear. We investigated neutrophil localization in mice using (111)In-labeled murine peripheral blood neutrophils, mature bone marrow neutrophils, and peritoneal exudate neutrophils to track in vivo localization of these different cell populations. Infused peripheral neutrophils were found to localize equally between liver and marrow sites by 4 h (31.2 +/- 1.9 vs. 31.9 +/- 1.8%), whereas exudate neutrophils predominantly localized to liver (42.0 +/- 1.1%) and marrow-derived neutrophils to the marrow (65.9 +/- 6.6%) where they were found to localize predominantly in the hematopoietic cords. Stimulation of marrow neutrophils before infusion caused a shift in localization from marrow to liver, and subsequent induction of an inflammatory site after infusion and marrow sequestration led to remobilization of infused marrow neutrophils but not of peripheral neutrophils. These results indicate that the marrow participates in removing neutrophils from circulation, with evidence supporting both storage and perhaps disposal functions. Furthermore, models for circulating neutrophil homeostasis should consider that the site of retention is governed by the maturation and activation states of the cell.

Conceptual database modeling: a method for enabling end users (radiologists) to understand and develop their information management applications

As medical technology advances at a rapid pace, clinicians become further and further removed from the design of their own technological tools. This is particularly evident with information management. For radiologists, clinical histories, patient reports, and other pertinent information require sophisticated tools for data handling. However, as databases grow more powerful and sophisticated, systems require the expertise of programmers and information technology personnel. The radiologist, the clinician end-user, must maintain involvement in the development of system tools to insure effective information management. Conceptual database modeling is a design method that serves to bridge the gap between the technological aspects of information management and its clinical applications. Conceptual database modeling involves developing information systems in simple language so that anyone can have input into the overall design. This presentation describes conceptual database modeling, using object role modeling, as a means by which end-users (clinicians) may participate in database development.

Conceptual Database Modeling for Understanding and Developing Information Management Applications

In response to rising health care costs and changing expectations concerning the quality of health care, information management is becoming increasingly important in the practice of medicine; more specifically, it is beginning to effect significant changes in radiology practice and patient care. Radiologic applications of information management include reporting diagnostic information generated from film interpretation as well as tracking utilization patterns of different imaging modalities and the variability of clinical outcomes, documenting the type of information sought by and provided to clinicians, and evaluating departmental quality standards and performance goals. Conceptual database modeling enables radiologists to understand and participate in the development of information systems, thereby improving the likelihood of successful results. In object-role modeling, groups of relevant objects and roles are identified and used to create elementary facts that form the "building blocks" for information models. The resultant models can easily be communicated, reviewed, and revised, allowing decreased development time and optimizing inclusion of relevant features in the target relational database. Increasing the amount of clinical and management input in the development process may help information systems better meet user needs, become accepted and more often used, and ultimately succeed.

Role of p38 mitogen-activated protein kinase in a murine model of pulmonary inflammation

Early inflammatory events include cytokine release, activation, and rapid accumulation of neutrophils, with subsequent recruitment of mononuclear cells. The p38 mitogen-activated protein kinase (MAPK) intracellular signaling pathway plays a central role in regulating a wide range of inflammatory responses in many different cells. A murine model of mild LPS-induced lung inflammation was developed to investigate the role of the p38 MAPK pathway in the initiation of pulmonary inflammation. A novel p38 MAPK inhibitor, M39, was used to determine the functional consequences of p38 MAPK activation. In vitro exposure to M39 inhibited p38 MAPK activity in LPS-stimulated murine and human neutrophils and macrophages, blocked TNF-alpha and macrophage inflammatory protein-2 (MIP-2) release, and eliminated migration of murine neutrophils toward the chemokines MIP-2 and KC. In contrast, alveolar macrophages required a 1000-fold greater concentration of M39 to block release of TNF-alpha and MIP-2. Systemic inhibition of p38 MAPK resulted in significant decreases in the release of TNF-alpha and neutrophil accumulation in the airspaces following intratracheal administration of LPS. Recovery of MIP-2 and KC from the airspaces was not affected by inhibition of p38 MAPK, and accumulation of mononuclear cells was not significantly reduced. When KC was instilled as a proinflammatory stimulus, neutrophil accumulation was significantly decreased by p38 MAPK inhibition independent of TNF-alpha or LPS. Together, these results demonstrate a much greater dependence on the p38 MAPK cascade in the neutrophil when compared with other leukocytes, and suggest a means of selectively studying and potentially modulating early inflammation in the lung.

The relations between temperament and empathy in 2-year-olds

The role of infant and toddler temperament in the prediction of empathy in 2-year-old children was examined. Assessments of temperament included reactivity and affect observed at 4 months of age, as well as inhibition at Age 2. Empathy was measured in 2-year-old children's responses to simulations of distress performed by their mothers and by an unfamiliar person. Children showed relatively more concern for the mother's distress, but they were also responsive to unfamiliar victims. Infants who were unreactive and showed little affect also showed less empathy toward the unfamiliar adult almost 2 years later. Inhibition toward an unfamiliar adult (but not toward the mother) at 2 years of age was negatively related to empathy. Inhibited temperament may thus have a major impact on young children's empathy in unfamiliar contexts. Findings also highlight the need to consider early underarousal as another dimension of temperament that may dampen expressions of empathic concern.

Aberrant wound healing and TGF-beta production in the autoimmune-prone MRL/+ mouse

Wound healing is a complex process that involves inflammation, apoptosis, growth, and tissue remodeling. The autoimmune-prone inbred mouse strain MRL/+ manifests accelerated and extensive healing to ear punch wounds, suggesting a link between immune defects and wound healing. Prior studies with lupus-prone mice have shown that hematopoietic cells of lupus-prone strains can transfer disease to otherwise non-autoimmune-prone recipients. In this study we performed reciprocal bone marrow transfers between MRL and the control strain B10.BR and found that radioresistant MRL/+ host cells, rather than hematopoietic cells, are required for the healing response. We have also made the novel observations that, compared to normal controls, MRL/+ hematopoietic cells overproduce TGF-beta1 and manifest impaired inflammatory responses to lipopolysaccharide challenge. These features suggest that the aberrant wound healing phenotype of MRL mice is independent of their propensity to develop autoimmunity.

The relations between temperament and empathy in 2-year-olds

The role of infant and toddler temperament in the prediction of empathy in 2-year-old children was examined. Assessments of temperament included reactivity and affect observed at 4 months of age, as well as inhibition at Age 2. Empathy was measured in 2-year-old children's responses to simulations of distress performed by their mothers and by an unfamiliar person. Children showed relatively more concern for the mother's distress, but they were also responsive to unfamiliar victims. Infants who were unreactive and showed little affect also showed less empathy toward the unfamiliar adult almost 2 years later. Inhibition toward an unfamiliar adult (but not toward the mother) at 2 years of age was negatively related to empathy. Inhibited temperament may thus have a major impact on young children's empathy in unfamiliar contexts. Findings also highlight the need to consider early underarousal as another dimension of temperament that may dampen expressions of empathic concern.

Selective activation and functional significance of p38alpha mitogen-activated protein kinase in lipopolysaccharide-stimulated neutrophils

Activation of leukocytes by proinflammatory stimuli selectively initiates intracellular signal transduction via sequential phosphorylation of kinases. Lipopolysaccharide (LPS) stimulation of human neutrophils is known to result in activation of p38 mitogen-activated protein kinase (MAPk); however, the upstream activator(s) of p38 MAPk is unknown, and consequences of p38 MAPk activation remain largely undefined. We investigated the MAPk kinase (MKK) that activates p38 MAPk in response to LPS, the p38 MAPk isoforms that are activated as part of this pathway, and the functional responses affected by p38 MAPk activation. Although MKK3, MKK4, and MKK6 all activated p38 MAPk in experimental models, only MKK3 was found to activate recombinant p38 MAPk in LPS-treated neutrophils. Of p38 MAPk isoforms studied, only p38alpha and p38delta were detected in neutrophils. LPS stimulation selectively activated p38alpha. Specific inhibitors of p38alpha MAPk blocked LPS-induced adhesion, nuclear factor-kappa B (NF-kappaB) activation, and synthesis of tumor necrosis factor-alpha (TNF-alpha). Inhibition of p38alpha MAPk resulted in a transient decrease in TNF-alpha mRNA accumulation but persistent loss of TNF-alpha synthesis. These findings support a pathway by which LPS stimulation of neutrophils results in activation of MKK3, which in turn activates p38alpha MAPk, ultimately regulating adhesion, NF-kappaB activation, enhanced gene expression of TNF-alpha, and regulation of TNF-alpha synthesis.

In vivo delivery of recombinant human growth hormone from genetically engineered human fibroblasts implanted within Baxter immunoisolation devices

Continuous delivery of therapeutic peptide to the systemic circulation would be the optimal treatment for a variety of diseases. The Baxter TheraCyte system is a membrane encapsulation system developed for implantation of tissues, cells such as endocrine cells or cell lines genetically engineered for therapeutic peptide delivery in vivo. To demonstrate the utility of this system, cell lines were developed which expressed human growth hormone (hGH) at levels exceeding 1 microgram per million cells per day. These were loaded into devices which were then implanted into juvenile nude rats. Significant levels of hGH of up to 2.5 ng/ml were detected in plasma throughout the six month duration of the study. In contrast, animals implanted with free cells showed peak plasma levels of 0.5 to 1.2 ng four days after implantation with no detectable hGH beyond 10 days. Histological examination of explanted devices showed they were vascularized and contained cells that were viable and morphologically healthy. After removal of the implants, no hGH could be detected which confirmed that the source of hGH was from cells contained within the device. The long term expression of human growth hormone as a model peptide has implications for the peptide therapies for a variety of human diseases using membrane encapsulated cells.

Type four fracture of the medial epicondyle: a true indication for surgical intervention

Fourteen consecutive cases with type 4 fracture of the medial epicondyle were evaluated following open reduction and internal fixation of the displaced medial epicondyle. The mean age was 9.7 years (range 6-16) and the mean follow-up was 17.2 months (range 12-24). Operative treatment yielded excellent results with no loss of functional range of motion, residual deformity or instability. There were three cases with pre-operative symptoms of ulnar nerve injury which made a good recovery following neurolysis of the ulnar nerve. Type 4 fractures are commonly associated with intra-articular entrapment of the ulnar nerve and result from serious damage to the soft tissues on the medial side of the elbow. Assessing instability is therefore of key importance, as is the intra-operative gravity stress-valgus test in assessing instability.

Tumors of minor salivary glands and the analysis of 106 cases

This study is based on 106 cases of predominantly minor salivary gland tumors which were received at the University of Oklahoma College of Dentistry Department of Oral Pathology Biopsy Service from 1972 to 1995. (In this study), 55% of the cases were benign and 45% were malignant. Benign tumors include pleomorphic adenoma (68%), monomorphic adenoma (10%), oncocytoma/oncocytosis (7%), papillary cystadenoma (14%), and myoepithelioma (2%). Of the malignant tumors, 34% were mucoepidermoid carcinoma, 17% adenoid cystic carcinoma, 21% adenocarcinoma, not otherwise specified (N.O.S.), 21% polymorphous low-grade adenocarcinoma, and 6% malignant mixed tumors. There was no difference in relative incidence of benign or malignant tumors between males and females. The 7th decade was the peak occurrence age for both benign and malignant and the palate was the most frequent location.

Desmoplastic fibroma of the mandible in a child: report of a case

A 6-year-old girl was seen with a history of progressive trismus and expansion of the right mandible over a 9-month period. Desmoplastic fibroma was diagnosed on biopsy. This report reviews the diagnostic criteria and surgical management of this uncommon primary bone tumor of the maxillofacial region.