Effects of twelve-month strength training subsequent to twelve-month stretching exercise in treatment of chronic neck pain

Previously, in a randomized study, we showed that women with chronic neck pain were able to perform intensive training for neck and shoulder muscles and that the increase in strength was accompanied by a reduction in pain and disability. The changes were significantly greater in the training groups compared with controls. The aim of the present study was to evaluate whether the controls would achieve similar results. Thus, 59 women in the control group initiated high-intensity strength training. Maximal isometric neck strength increased by 44% in both flexion and rotation and 27% in extension at the 2-year follow-up. Statistically and also clinically significant decreases in neck pain and disability indices occurred. Stretching and aerobic exercising during the first follow-up year produced only minor changes in both subjective and functional measures. Adding progressive strength training for the second year led to a significant improvement in neck strength and also to a considerable decrease in the pain and disability scores. Thus, to achieve effective rehabilitation in cases of chronic neck pain, a combination of strength training and stretching exercises are recommended.     

Vegetation Dynamics and Forest Landscape Restoration in the Upper Min River Watershed, Sichuan, China

The Upper Min River (UMR) watershed, with an area of 23,000 km² in the Upper Yangtze basin in Sichuan province, is ecologically and environmentally fragile. This situation is due to natural catastrophes and increasing anthropogenic disturbance. Forest cover has decreased dramatically, especially along the main Min River. Restoration of the vegetation in a watershed needs to consider the natural vegetation distribution and dynamics. In the UMR watershed, 625 sample plots were randomly placed to study the soil types, current vegetation distribution, vegetation dynamics, afforestation, and potential tree species for restoration. We investigated the relationship between vegetation types and soil orders, predicted the percentages of potential tree species for forest landscape restoration using logistic regression, identified priority areas for rapid restoration, and pinpointed areas for forest restoration where low precipitation is a constraint. The results showed that the vegetation types were well correlated with soil orders, and the latter could be used to deduce the potential vegetation for areas of degraded secondary forest. Priority areas for rapid restoration were demonstrated, and the difficult areas with precipitation as a limiting factor for vegetation restoration were specified. Suitable tree species were suggested for restoration on different soil orders at different elevations.     

Body mass patterns of Little Stints at different latitudes during incubation and chick-rearing

Due to the ‘double‐clutch’ mating system found in the arctic‐breeding Little Stint Calidris minuta, each parent cares for a clutch and brood alone. The resulting constraint on feeding time, combined with the cold climate and a small body size, may cause energetic bottlenecks. Based on the notion that mass stores in birds serve as an ‘insurance’ for transient periods of negative energy balance, but entail certain costs as well, body mass may vary in relation to climatic conditions and stage of the breeding cycle. We studied body mass in Little Stints in relation to breeding stage and geographical location, during 17 expeditions to 12 sites in the Eurasian Arctic, ranging from north Norway to north‐east Taimyr. Body mass was higher during incubation than during chick‐rearing. Structural size, as estimated by wing length, increased with latitude. This was probably caused by relatively more females (the larger sex) incubating further north, possibly after leaving a first clutch to be incubated by a male further south. Before and after correction for structural size, body mass was strongly related to latitude during both incubation and chick‐rearing. In analogy to a similar geographical pattern in overwintering shorebirds, we interpret the large energy stores of breeding Little Stints as an insurance against periods of cold weather which are a regular feature of arctic summers. Climate data showed that the risk of encountering cold spells lasting several days increases with latitude over the species’ breeding range, and is larger in June than in July. Maintaining these stores is therefore less necessary at southern sites and during the chick‐rearing period than in the incubation period. When guarding chicks, feeding time is less constrained than during incubation, temperatures tend to be higher than in the incubation period, reducing energy expenditure, and the availability of insect prey reaches a seasonal maximum. However, the alternative interpretation that the chick‐tending period is more energetically stressful than the incubation period, resulting in a negative energy balance for the parent, could not be rejected on the present evidence.     

Cold acclimation in silver birch (Betula pendula). Development of freezing tolerance in different tissues and climatic ecotypes

A number of environmental cues including short day photoperiod (SD) and low temperature (LT) are known to interact in triggering growth cessation, cold acclimation and other adaptive responses in temperate-zone tree species. Proper timing of these responses is particularly important for survival of trees in the boreal and subarctic regions. Therefore, we used a northern tree species, silver birch ( Betula pendula Roth) as an experimental model to investigate the effect of SD and LT on development of freezing tolerance and on levels of endogenous abscisic acid (ABA) in short-term experiments under controlled conditions. We characterized differences in SD and LT-induced cold acclimation between three different climatic ecotypes from southern, central and northern habitats. The results demonstrated that cold acclimation was rapidly triggered by exposing the plants to SD or LT, and that a combination of the different treatments had an additive effect on freezing tolerance. Freezing tolerance induction was not uniform in the different tissues, the buds and leaves developed freezing tolerance more rapidly than the stem, and the young leaves had a higher freezing tolerance than the old leaves. The ability of the leaves to respond to SD and LT and similarity of the bud and leaf responses indicate that birch leaves provide a rapid and convenient system for studies on molecular mechanisms of cold acclimation. Development of freezing tolerance was dependent on the climatic ecotype, the northern ecotype was clearly more responsive to both SD and LT than the two more southern ecotypes. Development of freezing tolerance induced by SD and LT was accompanied by transient changes in ABA levels. These alterations in ABA levels were ecotype-dependent, the northern ecotype reacting more strongly to the environmental cues.     

Na+-K+-ATPase alpha 2-gene and skeletal muscle characteristics in response to long-term overfeeding.

The role of Na(+)-K(+)-ATPase alpha2-gene BglII polymorphism in the changes of skeletal muscle metabolic properties after a 100-day overfeeding protocol conducted with 12 pairs of monozygotic twins is reported. The activities of oxoglutarate dehydrogenase (OGDH) and phosphofructokinase (PFK) were determined from muscle biopsies. A larger increase in the total fat mass (127 vs. 61%) (P < 0.05) and low-density lipoprotein cholesterol (20 vs. 0.7%) (P = 0.05) in 8.0/8.0-kb [3.3-kb negative (-); n = 7 pairs] than in 8.0/3.3 + 3.3/3.3-kb [3.3-kb positive (+); n = 5 pairs] subjects was observed. OGDH activity decreased in 3.3-kb(-) (-15%), whereas PFK (+26%) as well as the PFK-to-OGDH ratio (90%) increased. In contrast, among 3.3-kb(+), OGDH increased (+54%) together with a decrease in PFK (-1%) and PFK-to-OGDH ratio (-5%). These changes were significantly different between genotypes (P from <0.05 to 0.01). In conclusion, fat mass, low-density lipoprotein cholesterol, and skeletal muscle glycolytic-to-oxidative enzyme ratio increased more in the alpha2-gene 3.3-kb(-) subjects with overfeeding, suggesting more unfavorable metabolic changes compared with the 3.3-kb(+) subjects.     

Identification of the human cytochrome P450 enzymes involved in the in vitro biotransformation of lynestrenol and norethindrone

This study examined the cytochrome P450 (CYP) enzyme selectivity of in vitro bioactivation of lynestrenol to norethindrone and the further metabolism of norethindrone. Screening with well-established chemical inhibitors showed that the formation of norethindrone was potently inhibited by CYP3A4 inhibitor ketoconazole (IC(50)=0.02 microM) and with CYP2C9 inhibitor sulphaphenazole (IC(50)=2.13 microM); the further biotransformation of norethindrone was strongly inhibited by ketoconazole (IC(50)=0.09 microM). Fluconazole modestly inhibited both lynestrenol bioactivation and norethindrone biotransformation. Lynestrenol bioactivation was mainly catalysed by recombinant human CYP2C9, CYP2C19 and CYP3A4; rCYP3A4 was responsible for the hydroxylation of norethindrone. A significant correlation was observed between norethindrone formation and tolbutamide hydroxylation, a CYP2C9-selective activity (r=0.63; p=0.01). Norethindrone hydroxylation correlated significantly with model reactions of CYP2C19 and CYP3A4. The greatest immunoinhibition of lynestrenol bioactivation was seen in incubations with CYP2C-Ab. The CYP3A4-Ab reduced norethindrone hydroxylation by 96%. Both lynestrenol and norethindrone were weak inhibitors of CYP2C9 (IC(50) of 32 microM and 46 microM for tolbutamide hydroxylation, respectively). In conclusion, CYP2C9, CYP2C19 and CYP3A4 are the primary cytochromes in the bioactivation of lynestrenol in vitro, while CYP3A4 catalyses the further metabolism of norethindrone.     

Structural, biochemical, and physiological characterization of photosynthesis in two C4 subspecies of Tecticornia indica and the C3 species Tecticornia pergranulata (Chenopodiaceae)

Among dicotyledon families, Chenopodiaceae has the most C(4) species and the greatest diversity in structural forms of C(4). In subfamily Salicornioideae, C(4) photosynthesis has, so far, only been found in the genus Halosarcia which is now included in the broadly circumscribed Tecticornia. Comparative anatomical, cytochemical, and physiological studies on these taxa, which have near-aphyllous photosynthetic shoots, show that T. pergranulata is C(3), and that two subspecies of T. indica (bidens and indica) are C(4) (Kranz-tecticornoid type). In T. pergranulata, the stems have two layers of chlorenchyma cells surrounding the centrally located water storage tissue. The two subspecies of T. indica have Kranz anatomy in reduced leaves and in the fleshy stem cortex. They are NAD-malic enzyme-type C(4) species, with mesophyll chloroplasts having reduced grana, characteristic of this subtype. The Kranz-tecticornoid-type anatomy is unique among C(4) types in the family in having groups of chlorenchymatous cells separated by a network of large colourless cells (which may provide mechanical support or optimize the distribution of radiation in the tissue), and in having peripheral vascular bundles with the phloem side facing the bundle sheath cells. Also, the bundle sheath cells have chloroplasts in a centrifugal position, which is atypical for C(4) dicots. Fluorescence analyses in fresh sections indicate that all non-lignified cell walls have ferulic acid, a cell wall cross-linker. Structural-functional relationships of C(4) photosynthesis in T. indica are discussed. Recent molecular studies show that the C(4) taxa in Tecticornia form a monophyletic group, with incorporation of the Australian endemic genera of Salicornioideae, including Halosarcia, Pachycornia, Sclerostegia, and Tegicornia, into Tecticornia.     

New Fluorescence Parameters for the Determination of QA Redox State and Excitation Energy Fluxes

A number of useful photosynthetic parameters are commonly derived from saturation pulse-induced fluorescence analysis. We show, that q(P), an estimate of the fraction of open centers, is based on a pure 'puddle' antenna model, where each Photosystem (PS) II center possesses its own independent antenna system. This parameter is incompatible with more realistic models of the photosynthetic unit, where reaction centers are connected by shared antenna, that is, the so-called 'lake' or 'connected units' models. We thus introduce a new parameter, q(L), based on a Stern-Volmer approach using a lake model, which estimates the fraction of open PS II centers. We suggest that q(L) should be a useful parameter for terrestrial plants consistent with a high connectivity of PS II units, whereas some marine species with distinct antenna architecture, may require the use of more complex parameters based on intermediate models of the photosynthetic unit. Another useful parameter calculated from fluorescence analysis is Phi(II), the yield of PS II. In contrast to q(L), we show that the Phi(II) parameter can be derived from either a pure 'lake' or pure 'puddle' model, and is thus likely to be a robust parameter. The energy absorbed by PS II is divided between the fraction used in photochemistry, Phi(II), and that lost non-photochemically. We introduce two additional parameters that can be used to estimate the flux of excitation energy into competing non-photochemical pathways, the yield induced by downregulatory processes, Phi(NPQ), and the yield for other energy losses, Phi(NO).     

In vitro methods in the prediction of kinetics of drugs: focus on drug metabolism

The absorption, distribution, metabolism, excretion and toxicity (ADMET) properties of a candidate drug influence its final clinical success. These properties have traditionally been evaluated by using various in vivo animal approaches, but recently, a number of in vitro and in silico methods have been introduced to determine key ADMET features. Basic events, such as absorption through the gut wall, binding to plasma proteins, active and passive transfer through the blood-brain barrier, and various metabolic parameters, can now be screened with rapid in vitro and computer modelling methods. The focus in this short review is on the basic in vitro and in silico methods that are used for studying the metabolism properties of new drug molecules.     

Living nanovesicles--chemical and physical survival strategies of primordial biosystems

Life on Earth and Mars could have started with self-assembled nanovesicles similar to the present nanobacteria (NB). To resist extreme environmental stress situations and periods of nutritional deprivation, nanovesicles would have had a chemical composition protected by a closed mineralized compartment, facilitating their development in a primordial soup, or other early wet environment. Their survivability would have been enhanced if they had mechanisms for metabolic communication, and an ability to collect primordially available energy forms. Here, we establish an irreducible model system for life formation starting with NB.