Association of Cardiovascular Disease With Respiratory Disease

Background

The relationship between respiratory diseases and individual cardiovascular diseases, and the impact of cardiovascular diseases on mortality in patients with respiratory disease, are unclear.

Use of an Objective Structured Clinical Examination (OSCE) for the assessment of physician performance in the ultrasound evaluation of trauma.

BACKGROUND: A reliable means of assessing physician competency in performing ultrasound (US) is critical for training and credentialing. Objective Structured Clinical Examinations (OSCE) have been used successfully to assess clinical competency in other areas of surgical education but have not been applied previously to trauma ultrasound training. The objectives of this study were to assess physician performance in the focused abdominal sonography in trauma (FAST) examination by using a specifically designed OSCE, and to determine whether the OSCE detects differences in two determinants of competency (knowledge acquisition and clinical interpretation skills). METHODS: Eighty-two physicians in surgery (n = 49) and emergency medicine (n = 33) at a Level I trauma center were evaluated. All participated in a FAST course consisting of didactic sessions on US physics, indications, and technique, FAST examination videos, and a hands-on session with human models. The OSCE consisted of two parts: written examination that assessed factual knowledge, and videotape of real-time US examinations that assessed interpretation skills. The OSCE was administered before and after the FAST course. RESULTS: Significant improvements in postcourse OSCE scores were observed for factual knowledge (52.5 +/- 2.0 vs. 87.5 +/- 1.1, p < 0.001) and interpretation skills (27.2 +/- 1.4 vs. 62.9 +/- 1.3, p < 0.007). Scores for US interpretation were significantly lower than those for factual knowledge at both precourse (27.2 +/- 1.4 vs. 52.5 - 2.0, p < 0.001) and postcourse (62.9 +/- 1.3 vs. 87.5 +/- 1.1, p < 0.01). No performance differences were observed between surgeons and emergency medicine physicians and no effect of training level on test scores was observed. CONCLUSION: Knowledge acquisition and US interpretation skills can be assessed reliably with a specifically designed OSCE. Although both skills improved after participation in a FAST course, US interpretation scores were consistently lower than those for factual knowledge. This study supports the use of the objective structured clinical examination in both the design of ultrasound teaching programs and the assessment of physician competency.     

Addressing Breast Cancer Health Disparities in the Mississippi Delta Through an Innovative Partnership for Education,Detection, and Screening

Projects to reduce disparities in cancer treatment and research include collaborative partnerships and multiple strategies to promote community awareness, education, and engagement. This is especially needed in underserved areas such as the Mississippi Delta where more women are diagnosed at regional and distant stages of breast cancer. The purpose for this project was to increase the relatively low screening rate for African American women in the Mississippi Delta through a partnership between the Mississippi Network for Cancer Control and Prevention at The University of Southern Mississippi, The Fannie Lou Hamer Cancer Foundation and the Mississippi State Department of Health to decrease health disparities in breast cancer through increased awareness on self-early detection methods, leveraging resources to provide mammography screenings, and adequate follow-up with services and treatment for abnormal findings. Through this collaborative effort, over 500 women in three rural Mississippi Delta counties were identified, provided community education on early self-detection, and given appointments for mammography screenings within one fiscal year.     

Chronic low‐level lead exposure affects the monoaminergic system in the mouse superior olivary complex

Low‐level lead (Pb) exposure is associated with behavioral and cognitive dysfunction, but it is not clear how Pb produces these behavioral changes. Pb has been shown to alter auditory temporal processing in both humans and animals. Auditory temporal processing occurs in the superior olivary complex (SOC) in the brainstem, where it is an important component in sound detection in noisy environments and in selective auditory attention. The SOC receives a serotonergic innervation from the dorsal raphe, and serotonin has been implicated in auditory temporal processing within the brainstem and inferior colliculus. Because Pb exposure modulates auditory temporal processing, the serotonergic system is a potential target for Pb. The current study was undertaken to determine whether developmental Pb exposure preferentially changes the serotonergic system within the SOC. Pb‐treated mice were exposed to no Pb, very low Pb (0.01 mM), or low Pb (0.1 mM) throughout gestation and through 21 days postnatally. Brainstem sections from control and Pb‐exposed mice were immunostained for the vesicular monoamine transporter 2 (VMAT2), serotonin (5‐HT), and dopamine‐β‐hydroxylase (DβH; a marker for norepinephrine) in order to elucidate the effect of Pb on monoaminergic input into the SOC. Sections were also immunolabeled with antibodies to vesicular glutamate transporter 1 (VGLUT1), vesicular γ‐aminobutyric acid (GABA) transporter (VGAT), and vesicular acetylcholine transporter (VAChT) to determine whether Pb exposure alters the glutaminergic, GABAergic, or cholinergic systems. Pb exposure caused a significant decrease in VMAT2, 5‐HT, and DβH expression, whereas VGLUT1, VGAT, and VAChT showed no change. These results provide evidence that Pb exposure during development alters normal monoaminergic expression in the auditory brainstem. J. Comp. Neurol. 513:542–558, 2009. © 2009 Wiley‐Liss, Inc.     

Hormonal regulation of osteocalcin plasma production and clearance in sheep

The plasma osteocalcin (OC) concentration correlates with histological parameters of bone formation and has been used as an index of osteoblast activity. Although the rate of OC synthesis is likely to be a major determinant of the plasma OC level, the contribution of other processes, for example, OC plasma clearance, should be evaluated if changes in the plasma OC concentration are to be interpreted meaningfully. We have treated oophorectomized sheep with 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and glucocorticoids to alter the plasma OC concentration and used an 125I-OC infusion method to measure changes in the OC plasma clearance (PCR) and to calculate production (PPR) rates. 1,25-(OH)2D3 (8 micrograms/day by iv injection) increased plasma OC levels from 15.8 +/- 2.1 to 52.7 +/- 5.3 ng/ml (n = 10; P less than 0.0005) and the OC PPR from 0.9 +/- 0.08 to 2.6 +/- 0.17 mg/day (n = 5, P less than 0.0005). There was no effect on the OC PCR. Both triamcinolone acetonide (TA) and cortisol, administered by iv infusion, decreased the plasma OC concentration to less than 4 ng/ml and the OC PPR to less than 0.4 mg/day when infused in the doses 0.05-1.0 mg/h (TA) and 2.0 mg/h (cortisol). TA (0.05 mg/h) decreased plasma OC to an undetectable level within 24 h. The effect of cortisol infusion on the plasma OC level and the OC PPR was dose dependent in the range 0.2-2.0 mg/h. TA, infused at the rates of 0.25 and 1.0 mg/h, increased the OC PCR from 3.0 +/- 0.10 to 4.0 liters/h (P less than 0.005; n = 4) and from 2.6 +/- 0.10 to 3.9 +/- 0.10 liters/h (P less than 0.01; n = 3), respectively. It is concluded that the OC PPR and the plasma OC concentration in sheep are responsive to treatment with 1,25-(OH)2D3 and glucocorticoids. Although the changes in plasma OC concentration were attributable largely to effects on OC production, high infusion rates of the glucocorticoid TA led to a highly significant increase in OC plasma clearance. These findings suggest that alterations in OC clearance may contribute to the changes in plasma OC levels seen in some disease states, for example, glucocorticoid excess.     

Steroidogenesis by equine preovulatory follicles: relative roles of theca interna and granulosa cells

Estrous cycles in mares have several unique characteristics, including the presence of a long period of estrus and the absence of a typical LH surge. Like follicles of other species, equine preovulatory follicles are characterized by their ability to secrete large amounts of 17 beta-estradiol, but it is not clear which follicular cell type is responsible for estradiol synthesis in mares. To better understand the relative roles of theca interna and granulosa cells in follicular steroidogenesis, presumptive ovulatory follicles were obtained from mares during early estrus (first or second day of estrus; n = 4) and during late estrus (fourth or fifth day of estrus; n = 4). Preparations of theca interna and granulosa cells were cultured for 3 days in medium with or without equine LH, FSH, LH plus FSH, or CG (100 ng/ml) in the presence or absence of 0.5 microM testosterone, and culture media were assayed for progesterone, androstenedione, and 17 beta-estradiol. Progesterone was the predominant steroid secreted by granulosa cells in the absence of exogenous testosterone. Its accumulation was significantly higher in cultures of granulosa cells from late vs. early estrus (P less than 0.05), and all gonadotropins stimulated progesterone secretion at both stages of follicular development (P less than 0.05). In contrast, granulosa cells secreted very low amounts of androstenedione in vitro, and only very small amounts of 17 beta-estradiol were produced when cells were cultured in medium without testosterone. However, the addition of testosterone caused a 170-fold increase over control values in estradiol accumulation over 3 days of culture (P less than 0.0001), clearly indicating the presence of a very active aromatase enzyme system in equine granulosa cells. Steroid secretion by theca interna differed in several respects from secretion by granulosa cells. Theca interna from early and late estrous follicles secreted negligible amounts of progesterone in vitro, and equine gonadotropins had no effect on its secretion. Also, theca interna secreted only small amounts of estradiol in vitro, and its accumulation was not increased by the addition of exogenous testosterone. Also, in contrast to granulosa cell cultures, androstenedione was the predominant steroid secreted by theca interna from early and late estrous follicles. In conclusion, this study does not support the current model of equine follicular steroidogenesis, which holds that 17 beta-estradiol biosynthesis derives primarily from the theca interna layer.(ABSTRACT TRUNCATED AT 400 WORDS)     

Mutually opposing forces during locomotion can eliminate the tradeoff between maneuverability and stability

A surprising feature of animal locomotion is that organisms typically produce substantial forces in directions other than what is necessary to move the animal through its environment, such as perpendicular to, or counter to, the direction of travel. The effect of these forces has been difficult to observe because they are often mutually opposing and therefore cancel out. Indeed, it is likely that these forces do not contribute directly to movement but may serve an equally important role: to simplify and enhance the control of locomotion. To test this hypothesis, we examined a well-suited model system, the glass knifefish Eigenmannia virescens, which produces mutually opposing forces during a hovering behavior that is analogous to a hummingbird feeding from a moving flower. Our results and analyses, which include kinematic data from the fish, a mathematical model of its swimming dynamics, and experiments with a biomimetic robot, demonstrate that the production and differential control of mutually opposing forces is a strategy that generates passive stabilization while simultaneously enhancing maneuverability. Mutually opposing forces during locomotion are widespread across animal taxa, and these results indicate that such forces can eliminate the tradeoff between stability and maneuverability, thereby simplifying neural control.Animals routinely produce muscle commands that result in “antagonistic” (mutually opposing) forces during locomotion that either cancel out at each instant of time or average to zero over each gait cycle (1–5). This may seem surprising because these antagonistic forces do not contribute to the cycle-averaged movement of the center of mass of the animal. Such antagonistic forces are not only present during forward locomotion but in hovering for animals such as hummingbirds, hawkmoths, and electric fish; these animals produce large antagonistic forces and exhibit extraordinary maneuverability during station keeping (6–9). In this study, we demonstrate that active generation and differential control of such antagonistic forces can eliminate the tradeoff between stability and maneuverability during locomotion.Stability is generally defined as the resistance to, and recovery from, disturbances to an intended trajectory (10). Although maneuverability can be defined in several ways (11, 12), it is perhaps most generally recognized as the relative amplitude of the control signal required to change movement direction (13). That is, if a small change in the control amplitude effects a rapid change in direction, the system would be considered highly maneuverable. The potential for a tradeoff between the resistance to changes in direction and the ability to change direction appears self-evident (5, 10, 13, 14), and this tradeoff is indeed considered a fundamental challenge for the engineering design of airborne, submarine, and terrestrial vehicles (14–17). Many swimming, flying, and running animals, however, appear to use locomotor strategies that are extremely stable and yet facilitate the control of extraordinary maneuvers (4, 10, 18, 19).To investigate the relationship between antagonistic forces and locomotor control, we studied the glass knifefish, Eigenmannia virescens, that hovers and rapidly changes direction while producing opposing forces using a single elongated fin (Fig. 1A). Glass knifefish, like other knifefish, generate thrust force primarily through undulatory motions of an elongated anal fin (20–22). The ribbon fin consists of 217 ± 27 downward-pointing rays (table 4 in ref. 23; all statistics are quoted as mean ± SD unless otherwise noted), with each ray independently controlled by a set of muscles. These rays are oscillated in a plane transverse to the body axis and can be coordinated to produce a wave that travels longitudinally along the fin. In this study, we integrate biological experiments (Fig. 2), computational modeling, and experiments with a biomimetic robot (Fig. 1B and Fig. S1) to understand how the fish achieves both stability and maneuverability during rapid adjustments of its fore–aft position. Eigenmannia and other similar species of knifefish often partition their ribbon fin into two inward-counterpropagating waves (22) (Movie S1). The fin kinematics can be idealized as a pair of inward-traveling waves with parameters including oscillation frequency (f), wavelength (λ), and angular amplitude (θ) (Fig. 1C). We term the point where these two waves meet the “nodal point.” Although much is understood about the kinematics and mechanics of unidirectional traveling waves in a fluid (20, 24–28), far less is known (22, 29) about counterpropagating waves, particularly in relation to control.Open in a separate windowFig. 1.Three testbeds considered in this paper include the glass knifefish, a biomimetic robot, and a model of the swimming dynamics. (A) The glass knifefish E. virescens. Experiments with a biomimetic robot match force measurements predicted by a computational model of ribbon fin propulsion. (B) A biomimetic robot that has a ventral ribbon fin to emulate the fin of knifefish. The biomimetic robotic fin consists of 32 independently controlled rays, allowing for a wide range of fin kinematics, such as counterpropagating waves. (C) Fin is modeled as a pair of inward-traveling waves. Directions of head and tail waves and kinematics of the ribbon fin are shown in this schematic: angular deflection (θ), wavelength (λ), lengths of the two waves (L_head and L_tail), length of whole fin (L_fin), temporal frequency (f), and nodal point (red circle).Open in a separate windowFig. 2.Experimental apparatus. (A) The steady-state flow (0–12 cm/s) direction is shown. The fish keeps itself stationary relative to the PVC tube, and the kinematics of the ribbon fin are recorded from below through an angled mirror. (B) One annotated frame recorded from the experiment is shown. Both ends of the fin and nodal point are shown in red. All peaks and troughs of head and tail waves are shown with green and orange dots, respectively.     

Renal disease and the mouth

Oral manifestations of renal disease are common. They may present as unique signs of multi-system disease affecting the kidneys (such as vasculitis), or as common oral pathologies found at an increased prevalence in patients with end-stage renal disease. Despite more oral and dental disease in patients on renal replacement therapy, attendance at dental clinics is infrequent, and physician awareness of the problem is low. In our short review, aimed at renal, transplant, and general physicians, we discuss the link between clinical changes in the mouth and multi-systemic disease involving the kidney. We suggest a standardized approach to oral examination to increase diagnostic yield and discuss common oral complications in patients on dialysis or successfully transplanted. Finally, we suggest potential treatments for oral disease that nephrologists might safely institute.