Philippe P. Perrin

Bio: Philippe P. Perrin is an academic researcher from University of Lorraine. The author has contributed to research in topics: Balance (ability) & Posturography. The author has an hindex of 34, co-authored 74 publications receiving 3909 citations. Previous affiliations of Philippe P. Perrin include National Institutes of Health & Henri Poincaré University.

Five times sit to stand test is a predictor of recurrent falls in healthy community-living subjects aged 65 and older.

Abstract: in nonrenal anemia. A study of 1,005 subjects aged 65 and older demonstrated that the endogenous erythropoietin response is sluggish with age and decline in renal function, contributing to anemia. The findings in Table 1 lend some credibility to the fact that chronic anemia in the Agnihotri et al. study may have been, at least in part, secondary to CKD, in which the endogenous erythropoietin response to declining hemoglobin is known to be blunted, but the response to recombinant epoetin alfa therapy is favorable. In summary, many patients in the study, with a mean age in the 70s, may conceivably have had CKD of varying severity (with or without additional comorbid conditions that cause chronic anemia), and their favorable response to epoetin alfa was to be expected. However, the relatively larger doses of epoetin used (20–40,000 U weekly) bring into consideration the presence of factors that cause resistance to epoetin. Once hemoglobin increases in response to epoetin alfa, better QOL (and less fatigue) likely follows. Analyzing the data in Table 1 further, one would like to know which category of patients (based on GFR, normal versus CKD Stages 1 to 4, ferrokinetics, and non-renal anemias) had a better or poorer response to epoetin and accordingly an effect on QOL. Is it ‘‘chronic anemia’’ (of any etiology, based on the higher doses of epoetin used), or is it ‘‘anemia of CKD,’’ one cause of anemia of chronic disease, that responded favorably to epoetin therapy and improved QOL? These specific conclusions from the present study may have important implications for management of chronic anemia; the cause of anemia does matter!

Effects of physical and sporting activities on balance control in elderly people.

Abstract: OBJECTIVE: Balance disorders increase with aging and raise the risk of accidental falls in the elderly. It has been suggested that the practice of physical and sporting activities (PSA) efficiently counteracts these age related disorders, reducing the risk of falling significantly. METHODS: This study, principally based on a period during which the subjects were engaged in PSA, included 65 healthy subjects, aged over 60, who were living at home. Three series of posturographic tests (static, dynamic with a single and fast upward tilt, and dynamic with slow sinusoidal oscillations) analysing the centre of foot pressure displacements or electromyographic responses were conducted to determine the effects of PSA practice on balance control. RESULTS: The major variables of postural control were best in subjects who had always practised PSA (AA group). Those who did not take part in PSA at all (II group) had the worst postural performances, whatever the test. Subjects having lately begun PSA practice (IA group) had good postural performances, close to those of the AA group, whereas the subjects who had stopped the practice of PSA at an early age (AI group) did not perform as well. Overall, the postural control in the group studied decreased in the order AA > IA > AI > II. CONCLUSIONS: The period during which PSA are practised seems to be of major importance, having a positive bearing on postural control. It seems that recent periods of practice have greater beneficial effects on the subject's postural stability than PSA practice only at an early age. These data are compatible with the fact that PSA are extremely useful for elderly people even if it has not been a lifelong habit.

Posturography and risk of recurrent falls in healthy non-institutionalized persons aged over 65

Abstract: Background: A poor postural stability in older people is associated with an increased risk of falling. The posturographic tool has widely been used to assess balance control; howeve

Influence of Visual Control, Conduction, and Central Integration on Static and Dynamic Balance in Healthy Older Adults

Abstract: Aging is associated with decreased balance abilities, resulting in an increased risk of fall. In order to appreciate the visual, somatosensory, and central signals involved in balance control, sophisticated methods of posturography assessment have been developed, using static and dynamic tests, eventually associated with electromyographic measurements. We applied such methods to a population of healthy older adults in order to appreciate the respective importance of each of these sensorial inputs in aging individuals. Posture control parameters were recorded on a force-measuring platform in 41 healthy young (age 28.5 ± 5.9 years) and 50 older (age 69.8 ± 5.9 years) adults, using a static test and two dynamic tests performed by all individuals first with eyes open, then with eyes closed. The distance covered by the center of foot pressure, sway area, and anteroposterior oscillations were significantly higher, with eyes open or closed, in older people than in young subjects. Significant differences were noted in dynamic tests with longer latency responses in the group of old people. Dynamic recordings in a sinusoidal test had a more regular pattern when performed eyes open in both groups and evidenced significantly greater instability in old people. These data suggest that vision remains important in maintaining postural control while conduction and central integration become less efficient with age.

人唾液天疱疮抗原的纯化

Abstract: 1. Place animal in induction chamber and anesthetize the mouse and ensure sedation. 2. Once the animal is sedated, move it to a nose cone for hair removal using cream. Only apply cream to the area of the chest that will be utilized for imaging. Once the hair is removed, wipe area with wet gauze to ensure all hair is removed. 3. Move the animal to the imaging platform and tape its paws to the ECG lead plates and insert rectal probe. Body temperature should be maintained at 36-37°C. During imaging, reduce anesthesia to maintain proper heart rate. If the animal shows signs of being awake, use a higher concentration of anesthetic.

Research Agenda for Frailty in Older Adults: Toward a Better Understanding of Physiology and Etiology: Summary from the American Geriatrics Society/National Institute on Aging Research Conference on Frailty in Older Adults

Abstract: Evolving definitions of frailty, and improved understanding of molecular and physiological declines in multiple systems that may increase vulnerability in frail, older adults has encouraged investigators from many disciplines to contribute to this emerging field of research. This article reports on the results of the 2004 American Geriatrics Society/National Institute on Aging conference on a Research Agenda on Frailty in Older Adults, which brought together a diverse group of clinical and basic scientists to encourage further investigation in this area. This conference was primarily focused on physical and physiological aspects of frailty. Although social and psychological aspects of frailty are critically important and merit future research, these topics were largely beyond the scope of this meeting. Included in this article are sections on the evolving conceptualization and definitions of frailty; physiological underpinnings of frailty, including the potential contributions of inflammatory, endocrine, skeletal muscle, and neurologic system changes; potential molecular and genetic contributors; proposed animal models; and integrative, system biology approaches that may help to facilitate future frailty research. In addition, several specific recommendations as to future directions were developed from suggestions put forth by participants, including recommendations on definition and phenotype development, methodological development to perform clinical studies of individual-system and multiple-system vulnerability to stressors, development of animal and cellular models, application of population-based studies to frailty research, and the development of large collaborative networks in which populations and resources can be shared. This meeting and subsequent article were not meant to be a comprehensive review of frailty research; instead, they were and are meant to provide a more-targeted research agenda-setting process.

Functional Anatomy, Pathomechanics, and Pathophysiology of Lateral Ankle Instability.

Abstract: OBJECTIVE: To describe the functional anatomy of the ankle complex as it relates to lateral ankle instability and to describe the pathomechanics and pathophysiology of acute lateral ankle sprains and chronic ankle instability. DATA SOURCES: I searched MEDLINE (1985-2001) and CINAHL (1982-2001) using the key words ankle sprain and ankle instability. DATA SYNTHESIS: Lateral ankle sprains are among the most common injuries incurred during sports participation. The ankle functions as a complex with contributions from the talocrural, subtalar, and inferior tibiofibular joints. Each of these joints must be considered in the pathomechanics and pathophysiology of lateral ankle sprains and chronic ankle instability. Lateral ankle sprains typically occur when the rearfoot undergoes excessive supination on an externally rotated lower leg. Recurrent ankle sprain is extremely common; in fact, the most common predisposition to suffering a sprain is the history of having suffered a previous ankle sprain. Chronic ankle instability may be due to mechanical instability, functional instability, or most likely, a combination of these 2 phenomena. Mechanical instability may be due to specific insufficiencies such as pathologic laxity, arthrokinematic changes, synovial irritation, or degenerative changes. Functional instability is caused by insufficiencies in proprioception and neuromuscular control. CONCLUSIONS/RECOMMENDATIONS: Lateral ankle sprains are often inadequately treated, resulting in frequent recurrence of ankle sprains. Appreciation of the complex anatomy and mechanics of the ankle joint and the pathomechanics and pathophysiology related to acute and chronic ankle instability is integral to the process of effectively evaluating and treating ankle injuries.

Learning and Memory

Abstract: Experimental Psychology Its Scope and Method. IV. Learning and Memory. By Jean-Francois Le Ny, G. De Montpellier, G. Oleron and Cesar Flores. Translated by Louise Elkington. Edited by P. Fraisse and Jean Piaget. Pp. viii + 376. (Routledge and Kegan Paul: London, April 1970.) 80s.