Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures

Estimation of Ligament Loading and Anterior Tibial Translation in Healthy and ACL-Deficient Knees During Gait and the Influence of Increasing Tibial Slope Using EMG-Driven Approach

The purpose of this study was to develop a biomechanical model to estimate anterior tibial translation (ATT), anterior shear forces, and ligament loading in the healthy and anterior cruciate ligament (ACL)-deficient knee joint during gait. This model used electromyography (EMG), joint position, and force plate data as inputs to calculate ligament loading during stance phase. First, an EMG-driven model was used to calculate forces for the major muscles crossing the knee joint. The calculated muscle forces were used as inputs to a knee model that incorporated a knee–ligament model in order to solve for ATT and ligament forces. The model took advantage of using EMGs as inputs, and could account for the abnormal muscle activation patterns of ACL-deficient gait. We validated our model by comparing the calculated results with previous in vitro, in vivo, and numerical studies of healthy and ACL-deficient knees, and this gave us confidence on the accuracy of our model calculations. Our model predicted that ATT increased throughout stance phase for the ACL-deficient knee compared with the healthy knee. The medial collateral ligament functioned as the main passive restraint to anterior shear force in the ACL-deficient knee. Although strong co-contraction of knee flexors was found to help restrain ATT in the ACL-deficient knee, it did not counteract the effect of ACL rupture. Posterior inclination angle of the tibial plateau was found to be a crucial parameter in determining knee mechanics, and increasing the tibial slope inclination in our model would increase the resulting ATT and ligament forces in both healthy and ACL-deficient knees

Widespread platinum anomaly documented at theYounger Dryas onset in North American sedimentary sequences

Previously, a large platinum (Pt) anomaly was reported in the Greenland ice sheet at the Younger Dryas boundary (YDB) (12,800 Cal B.P.). In order to evaluate its geographic extent, fire-assay and inductively coupled plasma mass spectrometry (FA and ICP-MS) elemental analyses were performed on 11 widely separated archaeological bulk sedimentary sequences. We document discovery of a distinct Pt anomaly spread widely across North America and dating to the Younger Dryas (YD) onset. The apparent synchroneity of this widespread YDB Pt anomaly is consistent with Greenland Ice Sheet Project 2 (GISP2) data that indicated atmospheric input of platinum-rich dust. We expect the Pt anomaly to serve as a widely-distributed time marker horizon (datum) for identification and correlation of the onset of the YD climatic episode at 12,800 Cal B.P. This Pt datum will facilitate the dating and correlating of archaeological, paleontological, and paleoenvironmental data between sequences, especially those with limited age control

Opportunities for improving pLDH-based malaria diagnostic tests

<p>Abstract</p> <p>Background</p> <p>Monoclonal antibodies to <it>Plasmodium </it>lactate dehydrogenase (pLDH) have been previously used to format immunochromatographic tests for the diagnosis of malaria. Using pLDH as an antigen has several advantages as a sensitive measure of the presence of parasites within patient blood samples. However, variable results in terms of specificity and sensitivity among different commercially available diagnostic kits have been reported and it has not been clear from these studies whether the performance of an individual test is due simply to how it is engineered or whether it is due to the biochemical nature of the pLDH-antibody reaction itself.</p> <p>Methods</p> <p>A series of systematic studies to determine how various pLDH monoclonal antibodies work in combination was undertaken. Different combinations of anti-pLDH monoclonal antibodies were used in a rapid-test immunochromatographic assay format to determine parameters of sensitivity and specificity with regard to individual <it>Plasmodium </it>species.</p> <p>Results</p> <p>Dramatic differences were found in both species specificity and overall sensitivity depending on which antibody is used on the immunochromatographic strip and which is used on the colorimetric colloidal-gold used for visual detection.</p> <p>Discussion</p> <p>The results demonstrate the feasibility of different test formats for the detection and speciation of malarial infections. In addition, the data will enable the development of a universal rapid test algorithm that may potentially provide a cost-effective strategy to diagnose and manage patients in a wide range of clinical settings.</p> <p>Conclusion</p> <p>These data emphasize that using different anti-pLDH antibody combinations offers a tractable way to optimize immunochromatographic pLDH tests.</p

Mobility and other predictors of hospitalization for urinary tract infection: a retrospective cohort study

Abstract Background Many hospitalizations for residents of skilled nursing facilities are potentially avoidable. Factors that could prevent hospitalization for urinary tract infection (UTI) were investigated, with focus on patient mobility. Methods A retrospective cohort study was conducted using 2003–2004 data from the Centers for Medicare and Medicaid Services. The study included 408,192 residents of 4267 skilled nursing facilities in California, Florida, Michigan, New York, and Texas. The patients were followed over time, from admission to the skilled nursing facility to discharge or, for those who were not discharged, for 1 year. Cox proportional hazards regression was conducted with hospitalization for UTI as the outcome. Results The ability to walk was associated with a 69% lower rate of hospitalization for UTI. Maintaining or improving walking ability over time reduced the risk of hospitalization for UTI by 39% to 76% for patients with various conditions. For residents with severe mobility problems, such as being in a wheelchair or having a missing limb, maintaining or improving mobility (in bed or when transferring) reduced the risk of hospitalization for UTI by 38% to 80%. Other potentially modifiable predictors included a physician visit at the time of admission to the skilled nursing facility (Hazard Ratio (HR), 0.68), use of an indwelling urinary catheter (HR, 2.78), infection with Clostridium difficile or an antibiotic-resistant microorganism (HR, 1.20), and use of 10 or more medications (HR, 1.31). Patient characteristics associated with hospitalization for UTI were advancing age, being Hispanic or African-American, and having diabetes mellitus, renal failure, Parkinson's disease, dementia, or stroke. Conclusion Maintaining or improving mobility (walking, transferring between positions, or moving in bed) was associated with a lower risk of hospitalization for UTI. A physician visit at the time of admission to the skilled nursing facility also reduced the risk of hospitalization for UTI.http://deepblue.lib.umich.edu/bitstream/2027.42/112369/1/12877_2008_Article_125.pd

Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons

The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions

Mental health problems in youths committed to juvenile institutions: prevalences and treatment needs

Many international studies show that adolescents in coercive institutional care display high prevalences of mental disorders, especially in the form of disruptive behavior disorders [including attention-deficit/hyperactivity disorder (AD/HD), oppositional defiant disorder, and conduct disorder], anxiety disorders, and mood disorders. High degrees of overlap across mental disorders have also been reported. In addition, institutionalized adolescents are often traumatized. Despite this well-documented psychiatric morbidity, the mental health care needs of detained adolescents are often overlooked. The main objective of this study is to assess prevalences of psychiatric disorders, results of intelligence tests, and previous contacts with child and adolescent psychiatric services among adolescents in institutional care. DSM-IV diagnoses, mental health contacts, substance abuse, neurocognitive abilities, and school performance were registered in 100 adolescents (92 boys, 8 girls) aged 12–19 years (mean age 16.0; SD ± 1.5) consecutively committed to Swedish juvenile institutions between 2004 and 2007. At least one psychiatric disorder was diagnosed in 73% of the subjects: 48% met DSM-IV diagnostic criteria for AD/HD, 17% for an autism spectrum disorder, and 10% for a mental retardation. The collapsed prevalence for psychiatric disorders requiring specialist attention was 63%. Our data indicate that systematic diagnostic procedures are crucial in the treatment planning for institutionalized adolescents. Adequate treatment strategies need to be designed and implemented to meet the extensive mental health care needs of this vulnerable population

Design and validation of the Health Professionals' Attitudes Toward the Homeless Inventory (HPATHI)

BACKGROUND: Recent literature has called for humanistic care of patients and for medical schools to begin incorporating humanism into medical education. To assess the attitudes of health-care professionals toward homeless patients and to demonstrate how those attitudes might impact optimal care, we developed and validated a new survey instrument, the Health Professional Attitudes Toward the Homeless Inventory (HPATHI). An instrument that measures providers' attitudes toward the homeless could offer meaningful information for the design and implementation of educational activities that foster more compassionate homeless health care. Our intention was to describe the process of designing and validating the new instrument and to discuss the usefulness of the instrument for assessing the impact of educational experiences that involve working directly with the homeless on the attitudes, interest, and confidence of medical students and other health-care professionals. METHODS: The study consisted of three phases: identifying items for the instrument; pilot testing the initial instrument with a group of 72 third-year medical students; and modifying and administering the instrument in its revised form to 160 health-care professionals and third-year medical students. The instrument was analyzed for reliability and validity throughout the process. RESULTS: A 19-item version of the HPATHI had good internal consistency with a Cronbach's alpha of 0.88 and a test-retest reliability coefficient of 0.69. The HPATHI showed good concurrent validity, and respondents with more than one year of experience with homeless patients scored significantly higher than did those with less experience. Factor analysis yielded three subscales: Personal Advocacy, Social Advocacy, and Cynicism. CONCLUSIONS: The HPATHI demonstrated strong reliability for the total scale and satisfactory test-retest reliability. Extreme group comparisons suggested that experience with the homeless rather than medical training itself could affect health-care professionals' attitudes toward the homeless. This could have implications for the evaluation of medical school curricula