Conservation management options and actions: putative decline of coral cover at Palmyra Atoll, Northern Line Islands, as a case study.

Localised loss of live coral cover at Palmyra Atoll (central Pacific Ocean) has been attributed to increased temperature and/or sedimentation arising from alterations made to the lagoon system. It has been hypothesised that a causeway spanning the lagoon hinders water circulation, resulting in warmer and/or more turbid water flowing towards a site of high coral cover and diversity (Coral Gardens). Analyses of a multi-site and multi-year data set revealed no differences in mean temperature or turbidity values on either side of the causeway and provided no evidence of significantly warmer or more turbid water at Coral Gardens. We conclude that the putative decline in live coral cover cannot be attributed to the presence of the causeway and that proposed management actions involving modification to the causeway cannot achieve the conservation outcomes suggested of them.

Tarsal navicular fractures in major league baseball players at bat.

Tarsal navicular fractures in athletes, although rare, can present both a diagnostic and therapeutic dilemma. Failure to recognize this injury and initiate treatment early can have devastating consequences. The physician must have a high index of suspicion for the injury in any patient with midfoot pain after a direct blow. Two case reports of tarsal navicular fractures sustained by baseball players at bat in which the diagnosis was not made early are presented.

Experimental and computational simulation of total hip arthroplasty dislocation.

Other than fatal pulmonary embolism and deep infection, dislocation following total hip replacement remains probably the most vexing complication to patient and surgeon. Subluxation and dislocation are complex, poorly understood phenomena. Many important questions in this area unfortunately do not lend themselves well to clinical or registry study. Appropriate realistic laboratory models have been lacking. This article synthesizes new work undertaken independently by two groups of biomechanical investigators using very different, but complimentary, methodologies to study the mechanisms of dislocation, and especially the influence of specific design and surgical variables.

Topographic matching of selected donor and recipient sites for osteochondral autografting of the articular surface of the femoral condyles.

The purpose of this study was to define the topography of the articular surface of the femoral condyles and to develop a method for computerized topographic matching of donor and recipient sites for osteochondral transplantation. The condyles of seven fresh cadaveric femurs were mounted on the rotating stage of a laser-based coordinate measuring machine. An anatomic coordinate system defining the articular surface of the condyles was created. Customized software was developed to allow selection and topographic matching of osteochondral graft donor and recipient sites from any location on the surface of the condyles. For cartilage defects within the weightbearing portions of the medial or lateral femoral condyles, grafts taken from sites from the most medial or lateral portions of the patellar groove provided a significantly better topographic match than did grafts taken from the central intercondylar notch.

Differences in personal models among Latinos and European Americans: implications for clinical care.

OBJECTIVE: To describe and contrast the personal models of type 2 diabetes in European Americans (EAs) and Latinos and to highlight differences that require a reorientation of clinical care. RESEARCH DESIGN AND METHODS: A total of 116 EAs and 76 Latino individuals with type 2 diabetes were interviewed about their personal model of diabetes. Responses to open-ended questions about the perceived cause, nature, seriousness, course, and future course of diabetes and its impact on everyday life were analyzed using an iterative process, and categories of response were established. Responses were examined within ethnic group, and comparisons across ethnic groups were made for clinically significant differences. RESULTS: Disease descriptions about the nature of the disease were categorized as experiential, biomedical, or psychosocial. Disease descriptions varied significantly by ethnicity (chi2 = 35.92, 2 df, P < 0.001), with more Latinos using an experiential model and more EAs using a biomedical model. Significant differences in life changes caused by the disease were found, with EAs reporting changes in exercise and spontaneity and Latinos in fatigue and mood. Individuals with diabetes from both ethnic groups gave comparable assessments about the cause, seriousness, and effectiveness of treatments for the disease. CONCLUSIONS: Clinical practice that attends to the concerns and experiences of individuals with diabetes from diverse ethnic groups is warranted. Broad assessment of personal models in diverse ethnic groups is recommended.

Airways obstruction in patients with sarcoidosis: expiratory CT scan findings.

In patients with pulmonary sarcoidosis, air trapping as evidenced by expiratory high-resolution computed tomography (HRCT) is not specific for a given stage of disease. Air trapping can occur at the level of the secondary lobule, as well as in distributions suggesting sublobular, subsegmental, and segmental involvement. While air trapping can be a nonspecific finding, it is a common feature in patients with pulmonary sarcoidosis and is a supportive diagnostic finding.

The effect of femoral component head size on posterior dislocation of the artificial hip joint.

BACKGROUND: Posterior dislocation continues to be a relatively common complication following total hip arthroplasty. In addition to technical and patient-associated factors, prosthetic features have also been shown to influence stability of the artificial hip joint. In this study, a dynamic model of the artificial hip joint was used to examine the influence of the size of the head of the femoral component on the range of motion prior to impingement and posterior dislocation following total hip replacement. METHODS: Six fresh cadaveric specimens were dissected, and an uncemented total hip prosthesis was implanted in each. Each specimen was mounted in a mechanical testing machine and loaded with use of a system of seven cables attached to the femur and pelvis that simulated the action of the major muscle groups crossing the hip joint. The hip was taken through a range of motion similar to that experienced when rising from a seated position. The three-dimensional position of the femur at the points of impingement and dislocation was recorded electronically. The range of joint motion was tested with prosthetic femoral heads of four different diameters (twenty-two, twenty-six, twenty-eight, and thirty-two millimeters). RESULTS: Significant associations were noted between the femoral head size and the degree of flexion at dislocation in ten (p = 0.001), twenty (p < 0.001), and thirty (p = 0.003) degrees of adduction. Increasing the femoral head size from twenty-two to twenty-eight millimeters increased the range of flexion by an average of 5.6 degrees prior to impingement and by an average of 7.6 degrees prior to posterior dislocation; however, increasing the head size from twenty-eight to thirty-two millimeters did not lead to more significant improvement in the range of joint motion. The site of impingement prior to dislocation varied with the size of the femoral head. With a twenty-two-millimeter head, impingement occurred between the neck of the femoral prosthesis and the acetabular liner, whereas with a thirty-two-millimeter head, impingement most frequently occurred between the osseous femur and the pelvis. CONCLUSIONS: With the particular prosthesis that was tested, increasing the diameter of the femoral head component increased the range of motion prior to impingement and dislocation, decreased the prevalence of prosthetic impingement, and increased the prevalence of osseous impingement. CLINICAL RELEVANCE: These results suggest that femoral heads with a twenty-eight-millimeter diameter increase the range of motion after total hip replacement. This may be beneficial when additional factors compromising joint stability are encountered.

The family and disease management in Hispanic and European-American patients with type 2 diabetes.

OBJECTIVE: To determine the relationship between the characteristics of families involved in disease management and the self-care practices of Hispanic and European-American (EA) patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 74 Hispanic patients and 113 EA patients with type 2 diabetes recruited from managed care settings were assessed on three domains of family life (family structure/organization, family world view, and family emotion management [four scales]) and five areas of disease management (biological, general health and function status, emotional tone, quality of life, and behavioral [seven scales]). Analyses assessed the independent associations of patient sex, family, and sex by family interactions with disease management. RESULTS: Both sex and the three domains of family life were related to disease management, but the results varied by ethnic group. For EA patients, sex, family world view, and family emotion management were related to disease management (scores for Family Coherence were negatively associated with HbA1c level and depression, and poor scores for Conflict Resolution were linked with high depression); for Hispanic patients, sex and family structure/organization were related to disease management (high scores for Organized Cohesiveness were associated with good diet and exercise, and high scores for Family Sex-Role Traditionalism were related to high quality of life). No significant interactions with sex occurred. CONCLUSIONS: Characteristics of the family setting in which disease management takes place are significantly linked to patient self-care behavior, and these linkages vary by patient ethnicity. A family's multiple independent dimensions provide multiple targets for intervention, and differences in family norms, structures, and emotion management should be considered to ensure that interventions are compatible with the setting of disease management.

Disease management status: a typology of Latino and Euro-American patients with type 2 diabetes.

The number of indicators of chronic disease management is large and no practical framework is available to guide selection for use in intervention programs. In addition, it is often difficult to integrate multiple disease management indicators into a comprehensive picture of patient functioning. The authors present a heuristic framework for creating a profile of disease management and an empirically based descriptive typology of disease management behavior. From the literature, they identified 5 domains of disease management indicators: biologic, general health and functional status, emotional tone, quality of life, and behavioral. They selected 11 scales and assessed 187 patients with type 2 diabetes. Five statistically replicable patient disease management types were derived from exploratory and confirmatory cluster analyses and a descriptive narrative was created for each: balanced (33%), problematic (6%), coasters (34%), discouraged (16%), and distressed (11%). The typology describes different presentations of disease management that can be linked with patient-tailored interventions for patients with type 2 diabetes.

Beyond the biopsychosocial model: new approaches to doctor-patient interactions.

BACKGROUND: The biopsychosocial model has been a cornerstone for the training of family physicians; however, little is known about the use of this model in community practice. This study, conducted in an urban Native American health center, examined the application of the biopsychosocial model by an experienced family physician (Dr M). METHODS: Interactions between Dr M and 9 Native Americans with type 2 diabetes were audio-recorded following preliminary interviews. Interpretations of the interactions were elicited from Dr M through interpersonal process recall and interpretive dialogue sessions. The author analyzed this data using techniques from interpretive anthropology and narrative discourse analysis. RESULTS: In a preliminary interview, Dr M described a sophisticated biopsychosocial approach to practice. However, she viewed her actual interactions with these patients as imbued with misunderstanding, mistrust, and disconnection. This occurred in spite of her experience and commitment to providing culturally sensitive primary care. CONCLUSIONS: Biopsychosocial models of disease may conflict with patient-centered approaches to communication. To overcome difficulties in her practice environment, Dr M adopted a strategy that combined an instrumental biopsychosocial approach with a utilitarian mode of knowing and interacting with patients. The misunderstandings, mistrust, and constrained interactions point to deeper problems with the way knowledge is formed in clinical practice. We need further understanding of the interrelationships between physicians' clinical environments, knowledge of patients, and theories of disease. These elements are interwoven in the physicians' patient-specific narratives that influence their interactions in primary care settings.

The family and type 2 diabetes: a framework for intervention.

Four broad groups of factors have been linked with self-management behavior in type 2 diabetes over time: (1) characteristics of patients, (2) amount and management of stress, (3) characteristics of providers and provider-patient relationships, and (4) characteristics of the social network/context in which disease management takes place. Of these four, social network/context has received the least amount of study and has been described in terms not easily applicable to intervention. In this paper, we identified the social network/context of diabetes management as residing within the family. We defined the family for clinical purposes, reviewed the literature concerning what is known about the link between properties of the family context of care and outcomes in type 2 diabetes and other chronic diseases, and identified areas of family life that are relevant to diabetes management. This information was then used to demonstrate how a family context of care can serve as a clinical framework for integrating all four groups of factors that affect disease management. Implications of this approach for practice and research are described.

Differential receptor usage by measles virus strains.

Recently, we demonstrated that infection of cells with all measles virus (MV) strains tested was inhibited by antibodies against CD46, although not all strains caused downregulation of the MV receptor CD46 from the surface of human cells. We now show that infection of cells with MV strain WTFb, a variant of wild-type isolate WTF which has been isolated and propagated on human BJAB cells, is not inhibited by antibodies against CD46. In contrast, infection of cells with the closely related strain WTFv, a Vero cell-adapted variant of WTF, is inhibited by antibodies against CD46. This observation led us to investigate the interaction of these viruses and the vaccine strain Edmonston (Edm) with CD46 and target cells. Cellular receptors with high affinity binding for WTFb are present on BJAB cells, but not on transfected CD46-expressing CHO cells. In contrast to the Edm strain, virus particles and solubilized envelope glycoproteins of WTFb have a very limited binding capacity to CD46. Furthermore, we show that recombinant soluble CD46 either does not bind, or binds very weakly, to WTFb glycoproteins expressed on the cell surface. Our findings indicate that wild-type MV strain WTFb and vaccine strain Edm use different binding sites on human cells. In addition, the results suggest that MV strains may alternatively use CD46 and an unknown molecule as receptors, and that the degree of usage of both receptors may be MV strain-specific.

A method for open reduction and internal fixation of the unstable posterior sternoclavicular joint dislocation.

Posterior sternoclavicular joint (SCJ) dislocations are most often stable after reduction but may be associated with significant complications related to the location of the medial head of the clavicle within the mediastinum. In rare instances, a posterior SCJ dislocation is irreducible or redislocates after a closed reduction. Because of the potential hazards related to compression of vital structures within the superior mediastinum, open reduction and internal fixation is usually required. Although open reduction is widely accepted as the method of choice, the best method for achieving stable fixation remains unanswered. We present the case of an unstable SCJ stabilized, in anatomic position, with two large-bore cannulated screws in conjunction with open reduction. We believe that the risk of hardware migration reported with the use of pins and wires and its catastrophic complications are greatly minimized using our technique.

Mapping amino acids of the measles virus hemagglutinin responsible for receptor (CD46) downregulation.

We compared the amino acid sequences of groups of receptor (CD46) downregulating and nondownregulating measles virus (MV) hemagglutinins (Hs) and identified seven group-specific differences as candidates for the mediation of the observed differential effects. Using site-directed mutagenesis, we mutated the chosen amino acids of the H of MV-strain WTF (WTF-H), a nondownregulating H, and Introduced the corresponding amino acids of Edmonston-H (Edm-H), a downregulating H. We identified four amino acids, 211G, 243R, 451V, and 481Y, which influenced the downregulative function when introduced into WTF-H. The double mutation 451V and 481Y in WTF-H led to a degree of CD46 downregulation comparable to that of Edm-H. Conversely, introducing amino acids 451E and 481N into Edm-H resulted in a loss of the downregulative function. These results indicate that these amino acids play a decisive role in the H-CD46 interaction.