Linköping University

About: Linköping University is a education organization based out in Linköping, Sweden. It is known for research contribution in the topics: Population & Health care. The organization has 15671 authors who have published 50013 publications receiving 1542189 citations.

Arthroscopic partial and total meniscectomy: A long-term follow-up study with matched controls

Abstract: Purpose: The purpose of this study was to compare the clinical and radiographic outcome of arthroscopic partial and total meniscectomy. Type of Study: Retrospective outcome study. Methods: Thirty-six male patients with stable knees, no previous knee injury, and arthroscopic meniscectomy were matched into 2 groups: partial or total. In addition, a group of individuals with no known history of knee injury was matched to each patient with meniscectomy. All patients were re-examined by a clinical and radiographic examination 14 years after surgery. Results: At follow-up, radiographic changes, including Fairbank changes and joint space narrowing, were seen in 6 of 18 patients (33%) after partial meniscectomy and in 13 of 18 patients (72%) after total meniscectomy ( P 50% of the joint space was seen in 1 patient after partial meniscectomy but was present in 7 patients after total meniscectomy. In the healthy controls, 4 of 36 patients (11%) had radiographic changes but none had joint space narrowing. Fourteen years after surgery almost 70% of patients had a Lysholm score >94 (i.e., normal). Only 5 of 36 patients (14%) in the total meniscectomy group had knee symptoms during activities of daily living. A similar decline in activity levels according to Tegner was seen over time in the control group and in the 2 meniscectomy groups. Conclusions: The frequency of radiographic changes 14 years after meniscectomy is related to the size of the meniscus removed, but the grades of these changes are low and have little influence on activity and knee function. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 2 (February), 2002: pp 183–189

Oxidative stress causes relocation of the lysosomal enzyme cathepsin D with ensuing apoptosis in neonatal rat cardiomyocytes.

Abstract: Exposing neonatal rat heart myocytes to the redox cycling quinone naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) for 15 to 45 minutes led to a time-dependent release of cathepsin D from many secondary lysosomes to the cytosol, as analyzed by morphometry. Cathepsin D was detected electron microscopically using a pre-embedding immunostaining technique that utilizes antibodies conjugated to ultra-small (0.8-nm) gold particles and subsequent silver enhancement. The exposure to naphthazarin also caused a decrease in both the pH and the ATP level of the cells within the same time frame. Lipid peroxidation was, however, not detected. Pretreatment of the cultures with alpha-tocopherol succinate prevented cathepsin D relocation, as shown by immunofluorescence. After exposure to naphthazarin, cells were washed, and normal culture conditions were re-established for 18 hours. Many cells then showed apoptotic morphology (ie, cellular shrinkage and chromatin condensation) as analyzed by Giemsa staining. Also, 41% of the cells stained positive with the TUNEL technique, and DNA fragmentation was detected by separation of intact and fragmented DNA. Apoptosis was significantly decreased in cultures pretreated with alpha-tocopherol succinate.

In vivo studies concerning a pH gradient in human stratum corneum and upper epidermis.

Abstract: Human skin has an acid mantle of pH 4-6, contrasting with the almost neutral pH of the interior body and implying the existence of a pH gradient over the horny layer that might influence a variety of epidermal processes. In an attempt to characterize the pH gradient, we applied a glass electrode to the volar surface of the forearm before and after consecutive strippings with sello-tape. Before stripping, the surface pH (mean +/- SD) was 4.5 +/- 0.2 in men (n = 7) and 5.3 +/- 0.5 in women (n = 7), the values gradually increasing to pH 6.9 +/- 0.4 in men and 6.8 +/- 0.5 in women after about 100-120 tape strippings, which completely removed the stratum corneum. When plotted against the number of strippings, the pH values usually conformed to a sigmoid curve with inflection (50% change) after about 60 strippings, at a level corresponding histologically to the lower third of stratum corneum. Similar gradients were found also in skin of the abdomen and calf. Stripping with cyanoacrylate resin produced a similar gradient, even though this form of stripping was 10 times more effective. The healing process after tape stripping was studied by determining pH and transepidermal water loss in 5 persons over a period of 14 days. The importance of the re-established pH gradient is discussed in relation to the many pH-dependent enzymes operating in stratum corneum.

The PPH1 phosphatase is specifically involved in LHCII dephosphorylation and state transitions in Arabidopsis.

Abstract: The ability of plants to adapt to changing light conditions depends on a protein kinase network in the chloroplast that leads to the reversible phosphorylation of key proteins in the photosynthetic membrane. Phosphorylation regulates, in a process called state transition, a profound reorganization of the electron transfer chain and remodeling of the thylakoid membranes. Phosphorylation governs the association of the mobile part of the light-harvesting antenna LHCII with either photosystem I or photosystem II. Recent work has identified the redox-regulated protein kinase STN7 as a major actor in state transitions, but the nature of the corresponding phosphatases remained unknown. Here we identify a phosphatase of Arabidopsis thaliana, called PPH1, which is specifically required for the dephosphorylation of light-harvesting complex II (LHCII). We show that this single phosphatase is largely responsible for the dephosphorylation of Lhcb1 and Lhcb2 but not of the photosystem II core proteins. PPH1, which belongs to the family of monomeric PP2C type phosphatases, is a chloroplast protein and is mainly associated with the stroma lamellae of the thylakoid membranes. We demonstrate that loss of PPH1 leads to an increase in the antenna size of photosystem I and to a strong impairment of state transitions. Thus phosphorylation and dephosphorylation of LHCII appear to be specifically mediated by the kinase/phosphatase pair STN7 and PPH1. These two proteins emerge as key players in the adaptation of the photosynthetic apparatus to changes in light quality and quantity.