Forearm postural control during unloading: anticipatory changes in elbow stiffness

 In this study, the equilibrium-point hypothesis of muscle-torque generation is used to evaluate the changes in central control parameters in the process of postural-maintenance learning. Muscle torque is described by a linear spring equation with modifiable stiffness, viscosity, and equilibrium angle. The stiffness is considered to be the estimation of the central command for antagonist-muscle coactivation and the equilibrium angle to be the estimation of the reciprocal command for a shift of invariant characteristics of the joint. In the experiments, a load applied to the forearm was released. The subjects were instructed to maintain their forearm in the initial horizontal position. Five sessions of approximately twenty trials each were carried out by eight subjects. During two ”control” series, the load release was triggered by the experimenter. During three ”learning” series, the load supported by one forearm was released by the subject’s other hand. The elbow-joint angle, the angular acceleration, and the external load on the postural forearm were recorded. These recordings as well as anthropometric forearm characteristics were used to calculate the elbow-joint torque (which we called ”experimental”). Linear regression analysis was performed to evaluate the equilibrium angle, joint stiffness, and viscosity at each trial. The ”theoretical” torque was calculated using a linear spring equation with the found parameters. The good agreement observed between experimental and theoretical joint-torque time courses, apart from the very early period following unloading, argues in favor of the idea that the movement was mainly performed under a constant central command presetting the joint stiffness and the equilibrium angle. An overall increase in the stiffness occurred simultaneously with a decrease in the equilibrium angle during the ”learning” series in all the subjects. This suggests that subjects learn to compensate for the disturbing effects of unloading by increasing the joint stiffness. The mechanism possibly responsible for the presetting of the central control parameters is discussed. Received: 19 August 1997 / Accepted: 22 June 1998     

Prognosis of hematologic malignancies does not predict intensive care unit mortality

OBJECTIVE: To evaluate the correlation between specific prognosis of hematologic malignancies on the one hand and intensive care unit and hospital mortality in critically ill patients with hematologic malignancies on the other hand. DESIGN: Observational study during a 10-yr period. SETTING: A 22-bed medical-surgical intensive care unit. PATIENTS: A total of 84 consecutive patients with nonterminal hematologic malignancies with medical complications requiring intensive care. INTERVENTIONS: None. MEASUREMENTS: Demographic factors, acute physiology and organ dysfunction scores, microbiology, therapeutic support, and hematologic factors data on admission and during the intensive care unit stay were collected, together with mortality follow-up. Based on specific-disease prognostic factors and related published survival curves, the prognosis of hematologic malignancies was assessed and defined as good, intermediate, or poor according to a 3-yr survival probability of >50%, 20-50%, or <20%, respectively. MAIN RESULTS: Prognosis of hematologic malignancies does not predict intensive care unit or hospital mortality and almost reaches significance for 6-mo mortality (53%, 71%, and 84% rate for patients with good, intermediate, and poor prognosis, respectively, p =.058), but it determines long-term survival (p =.008). Intensive care unit, hospital, and 6-mo overall mortality rates were 38%, 61%, and 75%, respectively. Using multivariate analysis, intensive care unit mortality was best predicted on admission by respiratory failure and fungal infection, whereas hospital mortality was predicted by the number of organ failures, the bone marrow transplant status, and the presence of fungal infection. The Acute Physiology and Chronic Health Evaluation II and the Simplified Acute Physiology Score II had no prognostic value, whereas the difference of the Multiple Organ Dysfunction Score between at the time of admission and at day 5 allowed quick prediction of hospital mortality. Diseases with the poorest 6-mo prognosis were acute myeloid leukemia and non-Hodgkin lymphoma.CONCLUSION The severity of the underlying hematologic malignancies does not influence intensive care unit or hospital mortality. Short-term prognosis is exclusively predicted by acute organ dysfunctions and by a pathogen's aggressiveness. Therefore, reluctance to admit patients with nonterminal hematologic malignancies to the intensive care unit based only on the prognosis of their underlying hematologic malignancy does not seem justified.     

抗凝血相关因子抗体检测方法的建立及临床应用

目的抗磷脂抗体综合征(APS)患者血清中是否存在识别纤溶酶、凝血酶和活性蛋白C(APC)的抗磷脂抗体(aPL)。方法分别用凝血酶、纤溶酶和APC包被酶标板,建立抗纤溶酶、抗凝血酶和抗APC抗体的检测方法。结果在40例APS患者和40名正常对照的血清中,前者抗纤溶酶抗体阳性率为42.5%(17/40),抗凝血酶抗体阳性率为35%(14/40),对照组则两者均为阴性,差异有显著性(P<0.01)。但两组样本抗APC抗体检测结果的A值经检验差异无显著性(P>0.05)。结论APS患者的血清中可检测出抗纤溶酶、抗凝血酶和抗APC抗体,其临床意义有待进一步研究。     

SYMPTOMATIC COLITIS AS THE INITIAL PRESENTATION OF WEGENER'S GRANULOMATOSIS

SUMMARY Wegener's granulomatosis is a multisystem disorder which rarely presents with gastrointestinal involvement. We report a case in which colitis was the reason for hospital admission. Diagnosis may be difficult unless clinical, serological and histopathological features are all considered.     

Recent advances in the understanding of the role of nitric oxide in cardiovascular homeostasis

Nitric oxide synthases (NOS) are the enzymes responsible for nitric oxide (NO) generation. To date, 3 distinct NOS isoforms have been identified: neuronal NOS (NOS1), inducible NOS (NOS2), and endothelial NOS (NOS3). Biochemically, NOS consists of a flavin-containing reductase domain, a heme-containing oxygenase domain, and regulatory sites. NOS catalyse an overall 5-electron oxidation of one Nomega-atom of the guanidino group of L-arginine to form NO and L-citrulline. NO exerts a plethora of biological effects in the cardiovascular system. The basal formation of NO in mitochondria by a mitochondrial NOS seems to be one of the main regulators of cellular respiration, mitochondrial transmembrane potential, and transmembrane proton gradient. This review focuses on recent advances in the understanding of the role of enzyme and enzyme-independent NO formation, regulation of NO bioactivity, new aspects of NO on cardiac function and morphology, and the clinical impact and perspectives of these recent advances in our knowledge on NO-related pathways.     

Reflections on Jacques Paillard (1920–2006) — A pioneer in the field of motor cognition

This article reviews the scientific contributions of Jacques Paillard (1920–2006), who strengthened substantially the role of physiological psychology in the field of movement neuroscience. His research began in 1947 under the direction of the French neurophysiologist, Alfred Fessard (1900–1982), with whom he then collaborated for 9 years while an undergraduate and then graduate student and junior faculty member in psychology at the University of Paris (the Sorbonne). Paillard moved to the University of Marseille in 1957 as a Professor of Psychophysiology. In parallel, he became a founding member and administrator of the Institute of Neurophysiology and Psychophysiology, which began in 1963 on the Marseille campus of the National Center of Scientific Research (CNRS). Paillard retired from his university and CNRS positions in 1991 but he continued seminal research until his demise. Paillard advanced understanding of higher brain influences on human spinal motor mechanisms and the functional role of proprioception as revealed in patients deprived of such sensibility. He remains best known, however, for his work on human motor cognition. He reasoned that brain “maps” of the external world are constructed by the body's own movements and the central effects of their resulting central and peripheral feedback. He proposed two levels of interactive brain processing for the planning and/or execution of a reaching movement: 1) a sensorimotor level, using body posture as a key reference; and 2) a “higher” cognitive level for accurate movement performance, using learned representations of the position and shape of the environmental components, including the body, itself.     

Sepsis is associated with an upregulation of functional beta3 adrenoceptors in the myocardium

OBJECTIVE: To analyze the implication of the beta3-adrenoceptor (beta3-AR) pathway in human septic myocardium and a murine model of sepsis, a condition associated with myocardial depression. METHODS AND RESULTS: beta3-AR and eNOS protein abundance were increased (332+/-66.4% and 218+/-39.3; P<0.05) in hearts from septic patients. The effect of BRL37344, a beta3-AR-preferential agonist, was analyzed by videomicroscopy on the contractility of neonatal mouse ventricular myocytes (NMVM) incubated with conditioned medium from LPS-stimulated cultured macrophages (Mc-LPS+ medium). Stimulation of untreated NMVM with BRL37344 dose-dependently decreased the amplitude of contractile shortening (P<0.05). This response was abolished by L-NAME (NOS inhibitor). Incubation in Mc-LPS+ medium potentiated the depressing effect of BRL37344 (P<0.05) as well as of SR58611A (P<0.05) in wild-type myocytes. Importantly, the contractile depression was abrogated in cardiomyocytes from beta3-AR KO mice. CONCLUSIONS: beta3-AR are upregulated during sepsis in the human myocardium and by cytokines in murine cardiomyocytes, where they mediate an increased negative inotropic response to beta3 agonists. Activation of the beta3-AR pathway by catecholamines may contribute to the myocardial dysfunction in sepsis.     

Dental Expression and Role in Palliative Treatment

World Health Organization defines palliative care as the active total care of patients whose disease is not responding to curative treatment. Palliative care for the terminally ill is based on a multidimensional approach to provide whole-person comfort care while maintaining optimal function; dental care plays an important role in this multidisciplinary approach. The aim of the present study is to review significance of dentist''s role to determine whether mouth care was effectively assessed and implemented in the palliative care setting. The oral problems experienced by the hospice head and neck patient clearly affect the quality of his or her remaining life. Dentist plays an essential role in palliative care by the maintenance of oral hygiene; dental examination may identify and cure opportunistic infections and dental disease like caries, periodontal disease, oral mucosal problems or prosthetic requirement. Oral care may reduce not only the microbial load of the mouth but the risk for pain and oral infection as well. This multidisciplinary approach to palliative care, including a dentist, may reduce the oral debilities that influence the patient''s ability to speak, eat or swallow. This review highlighted that without effective assessment of the mouth, the appropriate implementation of care will not be delivered. Palliative dental care has been fundamental in management of patients with active, progressive, far-advanced disease in which the oral cavity has been compromised either by the disease directly or by its treatment; the focus of care is quality of life.     

Serum uric acid and risk of cardiovascular mortality: a prospective long-term study of 83,683 Austrian men

BACKGROUND: The role of serum uric acid (SUA) as an independent risk factor for cardiovascular disease (CVD) remains controversial, and little is known about its prognostic importance for mortality from congestive heart failure (CHF) and stroke. Few large-scale epidemiologic studies with sufficient follow-up have addressed the association of SUA and CVD mortality in apparently healthy men across a wide age range. METHODS: A cohort of 83 683 Austrian men (mean age, 41.6 years) was prospectively followed for a median of 13.6 years. We used Cox proportional hazards models adjusted for established risk factors to evaluate SUA as an independent predictor for CVD mortality. RESULTS: The highest quintile of SUA concentration (>398.81 mumol/L) was significantly related to mortality from CHF (P = 0.03) and stroke (P <0.0001); adjusted hazard ratios (95% confidence interval) for the highest vs lowest quintiles of SUA were 1.51 (1.03-2.22) and 1.59 (1.23-2.04), respectively. SUA was not associated, however, with mortality from acute, subacute, or chronic forms of coronary heart disease (CHD) after adjustment for potential confounding factors (P = 0.12). Age was a significant effect modifier for the relation of SUA to fatal CHF (P = 0.05), with markedly stronger associations found in younger individuals. CONCLUSIONS: Our study demonstrates for the first time in a large prospective male cohort that SUA is independently related to mortality from CHF and stroke. Although increased SUA is not necessarily a causal risk factor, our results suggest the clinical importance of monitoring and intervention based on the presence of an increased SUA concentration, especially because SUA is routinely measured.