No description available.

No description available.

Adult articular cartilage of many species including humans has a limited capacity for repair following injury. The hypothesis that this might be related to a lack of responsiveness to growth factors involved in growth was investigated. Cartilage explants from 4 child and 5 adult human donors were cultured in the presence of various growth factors. Incorporation of $ sp{35}$SO$ sb4$ into proteoglycans and $ sp3$H-thymidine into deoxyribonucleic acid used as measures of the biosynthetic response of cartilage. / Young cartilage showed the ability to behave in an autocrine or paracrine manner to stimulate its basal biosynthetic rate. Immature chondrocytes respond well to somatomedin C (insulin-like growth factor, IGF-I) and insulin but there was no significant stimulation in old cartilage. This data suggests a specific loss of responsiveness to IGF-I in mature cartilage. However, adult cartilage was stimulated by IGF-I and insulin after prolonged incubation times. Adult cartilage could also be stimulated by the addition of fetal calf serum and to some degree by platelet derived growth factor, indicating that adult chondrocytes still have the capacity to respond to external stimuli. The relevance of these results is discussed.

Complications resulting in flap failure and tissue necrosis constitute a serious and frequent problem to the plastic surgeon. Oxygen derived free radicals have been implicated in a variety of pathological processes including the ischemia reperfusion injury (IRI) occurring in skin flaps. Previous work with experimental rat skin flaps has suggested that the xanthine oxidase (XO) enzymatic system may be the major source for these toxic radicals. Before the clinician and the patient can benefit from these experimental findings an animal model which closer resembles the clinical setting needs to be tested. In the laboratory I examined the role of XO and its potent inhibitor allopurinol in the IRI of skin and myocutaneous flaps. I have found negligible levels of XO enzyme in pig and human skin when compared to the rat. I have also found that no beneficial effect on survival could be observed by treating the flaps with several different dose regimens of allopurinol. Based on my results I conclude that it is unlikely that xanthine oxidase is of major importance in the IRI of skin flaps.

Dynamic muscle function was studied in human normal, pathological (rheumatoid arthritic, post-meniscectomy) and prosthetic knee joints. Function in the knee extensor and flexor muscles was defined from data derived from evaluations of joint motion, strength and electromyographic activity. Strength was measured during maximal voluntary isokinetic knee extension and flexion movements (torque-angle curves) at 30(DEGREES)/s, 90(DEGREES)/s, and 180(DEGREES)/s. Electromyograms (surface electrodes, rectified, time averaged) were recorded from five muscles of the lower extremity during knee movements in activities: gait, stair ascent and descent and chair rising and sitting. Analysis of the electromyographic activity emphasized the pattern, relative amplitude and coordination of activation in the different muscles. Using these methods of evaluation, characteristic deviations in functional dynamic capacity in the knee extensor and flexor muscles were described for the three patient groups. These data are applicable to the optimization of therapeutic approaches and to the improvement of prosthetic design.

There are many theories but little sound data available to explain cutaneous sensory mechanisms. The high frequency of traumatic peripheral nerve injuries and cutaneous reconstructive procedures offers the clinician a colorful spectrum of phenomena with altered sensibility; however, the processes underlying hyperpathic or paresthetic and false localization states still elude our understanding. This experimental work addresses the topic of cutaneous reinnervation subsequent to nerve injury at the trunk level or at the region of the skin receptors. For the first time, single afferent fiber recordings are utilized to study reinnervation in the glabrous skin of the primate following nerve crush and cut injury. Also for the first time processes of reinnervation of skin transplants are investigated by neurophysiological analysis. Finally, patterns of hairy skin reinnervation are addressed subsequent to nerve transection and repair.

Transforming growth factor-beta (TGF-beta) signaling is involved in a wide array of cellular responses in both physiological and pathological conditions. Dysregulation of TGF-beta action can lead to impaired tissue homeostasis and several developmental defects. Mechanisms regulating TGF-beta signal transduction include modulation of TGF-beta signaling receptor activity by accessory receptors. Our group has recently identified a GPI-anchored TGF-beta1 binding protein, r150, and has shown that it is implicated in the regulation of TGF-beta signaling in keratinocytes. Recent molecular cloning of r150 in our laboratory shows that it represents CD109, a novel member of the alpha2-macroglobulin/complement (AMCOM) gene family. / We provided evidence showing that r150 contains an intact internal thioester bond, which is one of the defining characteristics of almost all members of the alpha2M/complement family, including CD109. Using affinity labeling, immunoprecipitation and Western blot analysis, we demonstrated that r150 binds TGF-beta1 with high affinity and associates with the TGF-beta receptors indicating that it is a component of the TGF-beta signaling complex. In addition, overexpression of r150 resulted in a significant decrease in TGF-beta-induced wound closure and TGF-beta-mediated growth inhibition. In contrast, blocking the expression of r150 by an antisense approach enhanced the above responses. Importantly, immunohistochemical analysis showed that r150 expression is markedly decreased in psoriatic lesions when compared to adjacent normal skin. / In summary, our results demonstrated that r150 is a negative modulator of TGF-beta responses in keratinocytes, and that it might be a potential marker or molecular target for therapeutic intervention in modulating TGF-beta action in human diseases where TGF-beta plays a pathophysiological role.

Strict regulation of cell growth, apoptosis and differentiation is essential for normal kidney development. The expression and activation of the Ste20-like kinase, SLK, is increased during renal development and recovery from ischemic acute renal failure, which recapitulates certain aspects of kidney development. SLK promotes apoptosis and may, therefore, regulate cell growth during development and healing. We propose that activation of SLK may be due to upregulation of expression, which may then favor homodimerization and/or reversal of autoinhibition. To test this hypothesis, the cDNA encoding the SLK catalytic domain (amino acids 1-373) was fused with a cDNA for a modified FK506 binding protein, Fv2E (Fv2E-SLK(1-373)). The plasmid was transfected into COS-1 cells, and a fusion protein of the expected molecular mass was expressed. Addition of AP20187 (an analog of FK506) induced dimerization of Fv2E-SLK(1-373). In an in vitro immune complex kinase assay, the dimeric Fv2E-SLK(1-373) displayed 1.7 fold greater activity, compared with the monomer. Glomerular epithelial cells were transiently transfected with Fv2E-SLK(1-373) and were treated with or without AP20187. Compared with the monomer, dimeric SLK(1-373) increased activation- specific phosphorylation of c-Jun N-terminal kinase and p38 kinase (1.5-2.1 fold) reflecting enhanced signaling via stress kinase pathways. In a second assay of SLK signaling, we monitored p53 transactivation following transient transfection of a luciferase reporter plasmid that contains a p53 cis-acting enhancer element. Addition of AP20187 to cells transfected with Fv2E-SLK(1-373) enhanced p53 reporter activity, compared with untreated. Finally, we monitored the effect of SLK dimerization on the activation of the proapoptotic protein, Bax. Cells were cotransfected with Fv2E-SLK(1- 373) and Bax-luciferase reporter cDNAs. Stimulation of the Bax reporter by SLK was 2.5 fold in the presence of AP20187 and 1.8 fold in / La régulation de la croissance cellulaire, de l'apoptose et de la différentiation cellulaire sont essentielles pour le développement rénal. L'expression et l'activation de la protéine kinase SLK (« Ste20-like kinase ») sont augmentés durant le développement rénal et la récupération d'une ischémie suite a un dommage rénal, qui en fait récapitule certains aspects du développement rénal. La kinase SLK peut promouvoir la mort cellulaire et pourrait être impliquée dans la régulation de la croissance durant le développement et le processus de guérison. Nous proposons que l'activation de la kinase SLK soit due à l'augmentation de son expression favorisant ainsi son homodimérisation et/ou le déblocage de son auto-inhibition. Pour tester cette hypothèse l'ADN complémentaire (ADNc) codant pour le domaine catalytique de SLK (acides aminés 1-373) a été fusionné avec un ADNc codant pour une version modifiée de la protéine de liaison FK506, appelée Fv2E. La construction résultante, Fv2E-SLK (1-373), a été transfectée dans des cellules COS-1 pour exprimer la protéine fusion résultante. L'addition d'AP20187 (un analogue de FK506) peut ensuite induire la dimérisation de Fv2E-SLK (1-373). In vitro, le dimère Fv2E-SLK (1-373) montre une augmentation de son activité de 1.7 fois par rapport à la version monomère. Des cellules épithéliales glomérulaires ont ensuite été transfectées transitoirement avec la construction Fv2E-SLK (1-373) et traitées ou non avec l'AP20187. Comparée au monomère, la forme dimérique du Fv2E-SLK (1-373) augmente la phosphorylation de c-Jun N-terminal kinase et de la kinase p38 de 1.5 à 2.1 fois respectivement, reflétant ainsi une activation qui semble liée au stress. Dans une autre expérience visant à mesurer l'activité de SLK nous avons mesuré la transactivation de p53 suite a une transfection transitoire d'un plasmide rapporteur contenant l'élément de réponse cis de p53.$

Cardiopulmonary resuscitation should generally not be offered to patients who suffer from a chronic obstructive pulmonary disease (COPD) exacerbation in the setting of end-stage lung disease (ESLD). Requests for CPR in this context may sometimes be uninformed, misguided, and the result of an unresolved grieving process by familial surrogates. While understandable, these requests rarely represent a truly autonomous patient perspective that is grounded in a competent, informed, and enlightened deliberation. / Alternatively, life-support technology and resuscitation is used appropriately when it is offered to patients with reversible disease, a disease for which functional recovery is possible, or to maintain a patient in an acceptable quality of life. It was never intended as, nor should it become, a treatment to delay the inevitable trajectory of a conscious or permanently unconscious and imminently dying patient. / When juxtaposed against perspectives of professional integrity, non-maleficence, distributive justice and basic human dignity, requests for CPR in this context rarely seem to be ethically persuasive or in the patient's best interests. / Pour les gens souffrant d'exacerbation en stade final des maladies respiratoires (SFMR) causée par une maladie pulmonaire obstructive chronique (MPOC), la réanimation cardio-pulmonaire est généralement à proscrire. Dans un tel contexte, la demande de réanimation peut être le résultant de mauvais renseignements, d'un choix malavisé ou même etre l'expression du refus des members de la famille face au deuil qu'ils auront à faire. Quoiqu'il est compréhensible de faire une telle demande, il est rare qu'elle soit bien fondée et représentative d'un choix éclairé et autonome de la part du patient ou de la patiente. / D'autre part, les technologies maintenant la vie ainsi que la réanimation sont utilisées de facon appropriée et juste lorsqu'elles sont offertes aux patient(e)s chez qui la maladie est réversible, où le rétablissent fonctionnel est possible ou afin de maintenir une qualité de vie acceptable. En aucun temps devrait-on considérer la reanimation afin de prolonger l'inévitable parcours du patient inconscient ou conscient et du patient pour qui la mort est imminente. fr / Lorsque juxtaposée aux notions d'intégrité professionnelle, la bienfaisance, une justice distributive et de celle de la dignité humaine, la demande de réanimation cardio-pulmonaire dans ce contexte semble rarement être éthiquement persuasive ou être dans les meilleurs intérêts du patient. fr

Background: Cell therapy using Human Bone Marrow Stem Cells (HBMSCs) has been shown to improve heart function after a myocardial infarction. The harvesting technique involved with bone marrow stem cells is invasive and yields a low cell number. There is now an increasing interest in Human Adipose Derived Stem Cells (HADSCs) as they are abundant and readily accessible from liposuction material. The present study was undertaken to investigate if HADSCs are superior than HBMSCs in myocardial regenerative therapy. Results: Both HADSCs and HBMSCs proliferated in a time dependent manner, however, the proliferative ability of HADSC was greater than HBMSCs. In addition, both cells differentiated to the osteoblast lineage confirming their multipotency when treated with induction medium. Furthermore, treatment of both cells with 5-AC resulted in positive immunostaining of cardiac markers, troponinI and connexin 43, however the expression of these markers was enhanced in HADSCs. This was further confirmed by western blot analysis, however 5-AC treatment did not exhibit cell contraction or multinucleation. In addition, these results were further confirmed by our in vivo study. Both cells were injected in the heart of a rat model of myocardial infarction and was monitored for ejection fraction (EF) and fractional shortening (FS) for 24 hours, 3 weeks and 6 weeks post-surgery. The cardiac function of the rats treated with stem cells was improved as demonstrated by increase in EF and FS, however, a greater improvement was seen with HADSCs compared with HBMSCs. This notion is further substantiated by our studies on left ventricular infarct size measurement, showing that HADSC are more potent in reduction of the infarct compared to HBMSCs. Conclusion: The data suggest that HADSCs may prove to be a more ideal alternative for regenerative therapy in the future. / La thérapie cellulaire à l'aide de cellules souches humaines de la moelle osseuses (CSHMOs) a été démontré d'améliorer la fonction cardiaque après un infarctus du myocarde. La technique de récolte des CSHMOs est pourtant invasive et donne un nombre de cellules viables faible. Il y a maintenant un intérêt croissant dans les cellules souches humaines dérivés du tissu adipeux (CSHTAs), car elles sont abondantes et facilement accessibles à partir des amas de graisses provenant des chirurgies de liposuccion. La présente étude a été menée pour vérifier si les CSHTAs sont supérieures aux CSHMOs dans la thérapie régénératrice du myocarde. Résultats: Les CSHTAs ainsi que les CSHMOs ont proliféré dans une manière temps dépendante, cependant, la capacité proliférative des CSHTAs était supérieure à celle des CSHMOs. De plus, les deux types de cellules souches ce sont différenciées en lignée ostéoblastique, affirmant leur capacité multipotent lorsqu'elles sont traitées avec le milieu d'induction. En outre, le traitement des deux types de cellules souches avec le 5-AC a entraîné l'immunomarquage positif de troponin I et de connexine 43, marqueurs cardiaques, cependant l'expression de ces marqueurs était plus robuste dans les CSHTAs. Cela a été confirmé par analyse d'immunobuvardage de type Western, cependant les cellules traité au 5-AC ne présentait pas de contraction des cellules ou le développement de plusieurs noyaux. En plus, ces résultats ont été confirmés par nos études in vivo. Les deux types de cellules ont été injectées dans le cœur d'un modèle de rat d'infarctus du myocarde et a été suivie pour la fraction d'éjection (FE) et la fraction de raccourcissement (FR) pour 24 heures, 3 semaines et 6 semaines post-chirurgie. La fonction cardiaque des rats traités avec les cellules souches a été améliorée, fait démontré par l'augmentation de l'FE et le FR, cependant, une plus grande amélioration de ce