Early cartilage abnormalities at the hip are associated with obesity and body composition measures – a 3.0T MRI community-based study

IntroductionAlthough obesity is a risk factor for hip osteoarthritis (OA), the role of body composition, if any, is unclear. This study examines whether the body mass index (BMI) and body composition are associated with hip cartilage changes using magnetic resonance imaging (MRI) in community-based adults.Methods141 community-based participants with no clinical hip disease, including OA, had BMI and body composition (fat mass and fat free mass) measured at baseline (1990 to 1994), and BMI measured and 3.0 T MRI performed at follow-up (2009–2010). Femoral head cartilage volume was measured and femoral head cartilage defects were scored in the different hip regions.ResultsFor females, baseline BMI (β = −26 mm³, 95% Confidence interval (CI) -47 to −6 mm³, p = 0.01) and fat mass (β = −11 mm³, 95% CI −21 to −1 mm³, p = 0.03) were negatively associated with femoral head cartilage volume. Also, while increased baseline fat mass was associated with an increased risk of cartilage defects in the central superolateral region of the femoral head (Odds Ratio (OR) = 1.08, 95% CI 1.00–1.15, p = 0.04), increased baseline fat free mass was associated with a reduced risk of cartilage defects in this region (OR = 0.82, 95% CI 0.67–0.99; p = 0.04). For males, baseline fat free mass was associated with increased femoral head cartilage volume (β = 40 mm³, 95% CI 6 to 74 mm³, p = 0.02).ConclusionsIncreased fat mass was associated with adverse hip cartilage changes for females, while increased fat free mass was associated with beneficial cartilage changes for both genders. Further work is required to determine whether modifying body composition alters the development of hip OA.     

Soldier-relevant loads impact lower limb biomechanics during anticipated and unanticipated single-leg cutting movements

This study quantified how body borne load impacts hip and knee biomechanics during anticipated and unanticipated single-leg cutting maneuvers. Fifteen male military personnel performed a series of single-leg cutting maneuvers with three different load configurations (light, ~6 kg, medium, ~20 kg, and heavy, ~40 kg). Subject-based means of the specific lower limb biomechanical variables were submitted to repeated measures ANOVA to test the main and interaction effects of body borne load and movement type. With body borne load, stance time (P<0.001) increased, while larger hip (P=0.027) and knee flexion (P=0.004), and hip adduction (P<0.001) moments, and decreased hip (P=0.002) and knee flexion (P<0.001), and hip adduction (P=0.003) postures were evident. Further, the hip (P<0.001) and ankle (P=0.024) increased energy absorption, while the knee (P=0.020) increased energy generation with body borne load. During the unanticipated maneuvers, the hip (P=0.009) and knee (P=0.032) increased energy generation, and peak hip flexion moment (P=0.002) increased relative to the anticipated movements. With the body borne load, participants adopted biomechanical patterns that decreased their locomotive ability including larger moments and reduced flexion postures of the lower limb. During the single-leg cut, participants used greater energy absorption from the large, proximal muscles of the hip and greater energy generation from the knee with the addition of load. Participant?s performance when carrying a range of loads was not compromised by anticipation, as they did not exhibit the hip and knee kinetic and kinematic adaptations previously demonstrated when reacting to an unplanned stimulus.     

The optimal value of BMI for the lowest risk of osteoporosis in postmenopausal women aged 40–88 years

The aim of this paper is to establish the optimal values of the body mass index (BMI) which would indicate the most favourable preservation of the bone mineral density in postmenopausal women. The material consists of the data of 369 healthy women aged between 40 and 88 years (mean age 67.84, SD = 6.70) inhabitants of Wroc?aw, which were followed up between 2001 and 2006. The absolute measure of bone mineral density (BMD) of the femoral neck was assessed using dual energy X-ray absorptiometry (DEXA), expressed in g/(100 mm²) and was transformed to T-score values. According to the value of BMI, the women were divided into eight groups, the reference group with value between 18.0 and 21.9 kg/m² and seven other groups beginning with the value 22.0 with a 2-point interval. Postmenopausal status was defined according to the occurrence of menstruation within the last 360 days. The women with osteopenia and osteoporosis were pooled together and comprised the risk group, whereas the other women comprised the normal group (T-score values above −1.0). The adjusted odds ratio showed the highest value for intervals between 24.0 and 25.9 units of BMI, and the lowest value for interval 26.0–27.9 units of BMI. The Youden index showed the lowest value in the 26.0–27.9 BMI kg/m² interval. For our sample the optimal value of BMI, with the lowest risk of osteopenia and/or osteoporosis was the value of 26.9 kg/m². A further increase of BMI does not result in a favourable effect on the bones, it rather intensifies negative phenomena in the body resulting in the onset of many diseases.     

Body segment inertial parameters and low back load in individuals with central adiposity

There is a paucity of information regarding the impact of central adiposity on the inertial characteristics of body segments. Deriving low back loads during lifting requires accurate estimate of inertial parameters. The purpose was to determine the body segment inertial parameters of people with central adiposity using a photogrammetric technique, and then to evaluate the impact on lumbar spine loading. Five participants with central adiposity (waist:hip ratio>0.9, waist circumference>102 cm) were compared to a normal BMI group. A 3D wireframe model of the surface topography was constructed, partitioned into 8 body segments and then body segment inertial parameters were calculated using volumetric integration assuming uniform segment densities for the segments. Central adiposity dependent increases in body segment parameters ranged from 12 to 400%, varying across segments (greatest for trunk) and parameters. The increase in mass distribution to the trunk was accompanied by an anterior and inferior shift of the centre of mass. A proximal shift in centre of mass was detected for the extremities, along with a reduction in mass distribution to the lower extremity. L5/S1 torques (392 vs 263 Nm) and compressive forces (5918 vs 3986 N) were substantially elevated in comparison to the normal BMI group, as well as in comparison to torques and forces predicted using published BSIP equations. Central adiposity resulted in substantial but non-uniform increases in inertial parameters resulting in task specific increases in torque and compressive loads arising from different inertial and physical components.     

Características de la fractura de cadera y posterior recuperación en pacientes mayores de 65 años con historia de caídas recurrentes

Recurrent falls affect between 14.8% and 19% of the elderly population, and are associated with an increased risk of fracture. We know little about the influence the history of recurrent falls may have on recovery after hip fracture.

Methods

Cohort study. The patients included were, over 65 years admitted during a 1 year period to the General University Hospital of Albacete with a hip fracture due to a fall. Recurrent falls were defined as a history of two or more falls within the 6 months prior to the fracture. Variables: demographic data, circumstances of fall, number of falls in the previous 6 months, type of fracture and its repair, comorbidity and drug treatment, cognitive status at admission (Pfeiffer test) and independence for activities of daily living (Barthel Index - BI) were collected. A subsample of patients with pre-fracture BI≥60 and Pfeiffer at admission≤4 was followed up at 3, 6 and 12 months.

Results

A total of 335 patients were admitted. Data were collected on 279 of them, 19.4% of whom had previously suffered two or more falls. The recurrent fallers had a worse mental status on admission, a higher number of associated diseases, a lower percentage of independence in dressing and in bed-chair transferring than patients without history of recurrent falls, all statistically significant. In the 201 patients followed up, the impairment on the BI after 12 months compared to the BI previous to fracture was higher in recurrent fallers (-20.8 ± 31.54 vs -10.73 ± 20.21, P = .04), focusing more on independence in eating (76% vs 91.9%, P < .05), grooming (72% vs 91,9%, P < .01), faecal continence (60% vs 78.7%, p < .05) and walking indoors (80% vs 93.3%, P < .05).

Conclusions

The recovery of independence after hip fracture is significantly lower in the group of recurrent fallers in patients without moderate or severe functional impairment previous to fracture and cognitively stable.     

Could martial arts fall training be safe for persons with osteoporosis?: a feasibility study

Background

Osteoporosis is a well-established risk factor for fall-related hip fractures. Training fall arrest strategies, such as martial arts (MA) fall techniques, might be useful to prevent hip fractures in persons with osteoporosis, provided that the training itself is safe. This study was conducted to determine whether MA fall training would be safe for persons with osteoporosis extrapolated from the data of young adults and using stringent safety criteria.

Methods

Young adults performed sideways and forward MA falls from a kneeling position on both a judo mat and a mattress as well as from a standing position on a mattress. Hip impact forces and kinematic data were collected. For each condition, the highest hip impact force was compared with two safety criteria based on the femoral fracture load and the use of a hip protector.

Results

The highest hip impact force during the various fall conditions ranged between 1426 N and 3132 N. Sideways falls from a kneeling and standing position met the safety criteria if performed on the mattress (max 1426 N and 2012 N, respectively) but not if the falls from a kneeling position were performed on the judo mat (max 2219 N). Forward falls only met the safety criteria if performed from a kneeling position on the mattress (max 2006 N). Hence, forward falls from kneeling position on a judo mat (max 2474 N) and forward falls from standing position on the mattress (max 3132 N) did not meet both safety criteria.

Conclusions

Based on the data of young adults and safety criteria, the MA fall training was expected to be safe for persons with osteoporosis if appropriate safety measures are taken: during the training persons with osteoporosis should wear hip protectors that could attenuate the maximum hip impact force by at least 65%, perform the fall exercises on a thick mattress, and avoid forward fall exercises from a standing position. Hence, a modified MA fall training might be useful to reduce hip fracture risk in persons with osteoporosis.

     

Characteristic gait patterns in older adults with obesity—Results from the Baltimore Longitudinal Study of Aging

Obesity in older adults is a growing public health problem. Excess weight causes biomechanical burden to lower extremity joints and contribute to joint pathology. The aim of this study was to identify specific characteristics of gait associated with body mass index (BMI). Preferred and maximum speed walking and related gait characteristics were examined in 164 (50–84 years) participants from Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted. Participants were divided into three groups based on their BMI: normal weight (19≤BMI<25 kg/m²), overweight (25≤BMI<30 kg/m²) and obese (BMI 30≤BMI<40 kg/m²). Total ankle generative mechanical work expenditure (MWE) in the anterior–posterior (AP) plane was progressively and significantly lower with increase in BMI for both preferred (p=0.026) and maximum speed walking (p<0.001). In the medial–lateral (ML) plane, total knee generative MWE was higher in obese participants in the preferred speed task (p=0.002), and total hip absorptive MWE was higher in obese in both preferred speed (p<0.001) and maximum speed (p=0.002) walking task compared to the normal weight participants. Older adults with obesity show spatiotemporal gait patterns that may help in reducing contact impacts. In addition, in obese persons mechanical energy usages tend to be lower in the AP plane and higher in the ML plane. Since forward progression forces are mainly implicated in normal walking, this pattern found in obese participants is suggestive of lower energetic efficiency.     

Methodological considerations of task and shoe wear on joint energetics during landing

To better understand methodological factors that alter landings strategies, we compared sagittal plane joint energetics during the initial landing phase of drop jumps (DJ) vs. drop landings (DL), and when shod vs. barefoot. Surface electromyography, kinematic and kinetic data were obtained on 10 males and 10 females during five consecutive drop landings and five consecutive drop jumps (0.45 m) when shod and when barefoot. Energy absorption was greater in the DJ vs. DL (P = .002), due to increased energy absorption at the hip during the DJ. Joint stiffness/impedance was more affected by shoe condition, where overall stiffness/impedance was greater in shod compared to barefoot conditions (P = .036). Further, hip impedance was greater in shod vs. barefoot for the DL only (via increased peak hip extensor moment in DL), while ankle stiffness was greater in the barefoot vs. shod condition for the DJ only (via decreased joint excursion and increased peak joint moment in DJ vs. DL) (P = .011). DJ and DL place different neuromechanical demands upon the lower extremities, and shoe wear may alter impact forces that modulate stiffness/impedance strategies. The impact of these methodological differences should be considered when comparing landing biomechanics across studies.     

Anaerobic digestion of source-segregated domestic food waste: Performance assessment by mass and energy balance

An anaerobic digester receiving food waste collected mainly from domestic kitchens was monitored over a period of 426 days. During this time information was gathered on the waste input material, the biogas production, and the digestate characteristics. A mass balance accounted for over 90% of the material entering the plant leaving as gaseous or digestate products. A comprehensive energy balance for the same period showed that for each tonne of input material the potential recoverable energy was 405 kWh. Biogas production in the digester was stable at 642 m³ tonne⁻¹ VS added with a methane content of around 62%. The nitrogen in the food waste input was on average 8.9 kg tonne⁻¹. This led to a high ammonia concentration in the digester which may have been responsible for the accumulation of volatile fatty acids that was also observed.     

Association of leptin receptor gene Q223R polymorphism on lipid profiles in comparison study between obese and non-obese subjects

Objectives

Leptin is a hormone secreted from adipocytes. It regulates metabolism and energy homeostasis through the leptin receptor (LEPR) which is localized centrally in hypothalamus as well as in peripheral tissues. The aim of this study was to investigate the association of leptin receptor gene Q223R polymorphism on obesity in association with body mass index (BMI), lipid parameters, plasma leptin levels and homeostasis model assessment of insulin resistance (HOMA-IR).

Design and methods

The study included 110 obese and 90 non-obese subjects. The LEPR Q223R polymorphism was determined by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Plasma leptin levels, serum lipid and antropometric parameters were measured.

Results

No association was found between LEPR gene Q223R polymorphism and BMI in both study and control groups. Strikingly study group with non-obese subjects and with the RR genotype (homozygous mutant) had significantly higher serum total cholesterol (p < 0.001) and low density lipoprotein cholesterol (LDL-cholesterol) levels (p < 0.05) than QR (heterozygous) and QQ (wild type) genotypes. In obese group, subjects with the RR genotypes had significantly higher triglycerides (p < 0.05) levels, waist (p < 0.05) and hip circumferences (p < 0.001) than the QQ and QR genotypes.

Conclusions

Our results suggest that the LEPR gene Q223R polymorphism has an association with waist and hip circumferences in obese group but no direct association with obesity although there is a significant influence on lipid profile both in obese and non-obese subjects.     

Excitation energy-transfer and the relative orientation of retinal and carotenoid in xanthorhodopsin

The cell membrane of Salinibacter ruber contains xanthorhodopsin, a light-driven transmembrane proton pump with two chromophores: a retinal and the carotenoid, salinixanthin. Action spectra for transport had indicated that light absorbed by either is utilized for function. If the carotenoid is an antenna in this protein, its excited state energy has to be transferred to the retinal and should be detected in the retinal fluorescence. From fluorescence studies, we show that energy transfer occurs from the excited singlet S₂ state of salinixanthin to the S₁ state of the retinal. Comparison of the absorption spectrum with the excitation spectrum for retinal emission yields 45 ± 5% efficiency for the energy transfer. Such high efficiency would require close proximity and favorable geometry for the two polyene chains, but from the heptahelical crystallographic structure of the homologous retinal protein, bacteriorhodopsin, it is not clear where the carotenoid can be located near the retinal. The fluorescence excitation anisotropy spectrum reveals that the angle between their transition dipole moments is 56 ± 3°. The protein accommodates the carotenoid as a second chromophore in a distinct binding site to harvest light with both extended wavelength and polarization ranges. The results establish xanthorhodopsin as the simplest biological excited-state donor-acceptor system for collecting light.     

Association between ABO blood group and osteoporosis among postmenopausal women of North India

The present study is an attempt to examine possible associations between ABO blood groups and the risk of osteoporosis among postmenopausal women of North India. This cross-sectional study involved 250 postmenopausal women from North India, ranging in age from 45 to 80 years. Four anthropometric measurements (height, weight, waist circumference and hip circumference), blood sample (ABO status and haemoglobin concentration) and grip strength (dominant as well as non-dominant hand) of all the participants were taken. Bone mineral density (BMD) was evaluated by using dual energy X-ray absorptiometry (DXA) at lumbar spine (L1–L4) and proximal femur. Analysis of data revealed that at lumbar spine (L1–L4) osteoporosis was more prevalent among individuals with blood group A (31.58%), followed by those with blood group B (29.67%), AB (28.57%) and then blood group O (15%), whereas for proximal femur individuals with blood group AB (21.43%) showed the highest prevalence of osteoporosis followed by a decreasing trend from blood group A (17.54%) to B (12.08%) and then O (5%). Total prevalence of osteoporosis was 26.4% in lumbar spine and 13.2% in proximal femur, indicating that lumbar spine had an elevated risk for osteoporosis among postmenopausal women. All the anthropometric variables, haemoglobin concentration as well as grip strength of individuals with blood group O demonstrated non-significant differences with non-O blood group except for weight and body mass index, where differences were statistically significant. Women with blood group O exhibited significantly higher bone mineral density for lumbar spine (0.90 g/cm² vs. 0.85 g/cm², p < 0.05) and proximal femur (0.87 g/cm² vs. 0.79 g/cm², p < 0.05) as compared to those with non-O blood group, thereby suggesting an increasing risk of osteoporosis among individuals with non-O blood group.     

Influence of sward maturity and pre-conditioning temperature on the energy production from grass silage through the integrated generation of solid fuel and biogas from biomass (IFBB): 2. Properties of energy carriers and energy yield

In order to determine influencing parameters on energy production of the IFBB process, herbage from a lowland hay meadow (Arrhenaterion) was sampled and ensiled at eight dates between 27 April and 21 June 2007. The silage from each date was processed in six IFBB treatments with and without hydrothermal conditioning at different temperatures. Methane yields and higher heating values were determined and an energy balance was calculated with whole-crop digestion (WCD) of the silage as reference system. Maximum net energy yields were 10.2 MWh ha⁻¹ for the IFBB treatment without hydrothermal conditioning and 9.0 MWh ha⁻¹ for the treatment with hydrothermal conditioning at 50 °C. WCD achieved a maximum net energy yield of 3.7 MWh ha⁻¹. Energy conversion efficiency ranged from 0.24 to 0.54 and was predicted with high accuracy by temperature of hydrothermal conditioning as well as concentration of neutral detergent fibre and dry matter in the silage (R² = 0.90).     

Synthesis, characterization and electrode adsorption studies of porphyrins coordinated to ruthenium(II) polypyridyl complexes

Two new porphyrins, meso-tris-3,4-dimethoxyphenyl-mono-(4-pyridyl)porphyrin (H₂MPy3,4DMPP) and meso-tris-3-methoxy-4-hydroxyphenyl-mono-(4-pyridyl)porphyrin (H₂MPy3M4HPP), and their ruthenium analogs obtained by coordination of [Ru(bpy)₂Cl]⁺ groups (where bpy = 2,2′-bipyridine) to the pyridyl nitrogens have been synthesized and studied by electronic absorption spectroscopy, cyclic voltammetry and spectroelectrochemistry. These ruthenated porphyrins couple Ru chromophores to porphyrins containing electroactive meso-substituents. The highest energy electronic absorption for the ruthenated complexes is assigned as a bpy(π) → bpy(π*) intraligand charge transfer while the next lowest energy electronic absorption is assigned as Ru(dπ) → bpy(π*) metal-to-ligand charge transfer (MLCT) transition. The Ru^III/II couples occur at approximately 0.95 V versus the SHE reference electrode in acetonitrile solutions. The first oxidation of the porphyrin is localized on the 3,4-dimethoxyphenyl and 3-methoxy-4-hydroxyphenyl substituents, respectively. Electroactive surfaces result from adsorption of these compounds onto glassy carbon electrodes followed by anodic cycling in acidic media.     

Computational investigation of ethene trimerisation catalysed by cyclopentadienyl chromium complexes

Intermediates and transition states of the reaction cycle for the trimerisation of ethene catalysed by the initial catalyst precursor [η⁵-CpCrCl₂]₂ have been characterised by modeling, starting from the species η⁵-CpCrMe₂. This is a simplified model system of the actual catalytically active system containing bulky cyclopentadienyls. The ground-state multiplicity configuration was determined to be that of a quartet, in the case of non-chlorinated Cr(III) species, and a triplet for corresponding chlorinated Cr(IV) analogues. Geometry optimizations were performed on all intermediates, using their ground-state multiplicity, and all relevant transition states were located and subsequently optimised. The effect of an additional chlorine ligand on the chromium centre (viz. species of the form η⁵-CpCrClL_n) on the activation energy barriers was also determined for two key high energy transformations. It was found that the activation energy barriers are lowered significantly upon the addition of a chlorine ligand to the chromium centre. The rate determining step for the non-chlorinated, Cr(III) system, was calculated as requiring a free energy value of 88 kJ mol⁻¹, with the chlorinated Cr(IV) analogue at 56 kJ mol⁻¹ in the same step. The process of ethene tetramerisation was found to be unfeasible with the system, with a free energy barrier of 162 kJ mol⁻¹ associated with this transformation.     

Column-switching HPLC–MS/MS analysis of ropivacaine in serum,ultrafiltrate and drainage blood for validating the safety of blood reinfusion

A high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS–MS) method, using back-flush column-switching was developed for total drug concentrations of ropivacaine in serum and drainage blood in the measuring range 0.1–10 μg/mL. Samples were diluted with internal standard (²H₇-ropivacaine) and extraction buffer, centrifuged and injected directly onto a BioTrap 500 MS extraction column. Using a time programmed six-port valve switch, ropivacaine was back-flushed onto a Zorbax SB-Aq analytical column, gradient eluted and finally detected after electro spray ionisation and multiple reaction monitoring (MRM) of the transitions m/z 275 → m/z 126 and m/z 282 → m/z 133 for ropivacaine and ²H₇-ropivacaine, respectively. Accuracy (bias-%) was −1.5 to 5.8% and intermediate precision (C.V.) was 1.4–3.1%. The low sample amount required (10 μL), high specificity and short run time (6 min) makes it very suitable for determination of ropivacaine. Using the same methodology as described above and 200 μL ultrafiltrate, the free drug concentrations of ropivacaine in serum could be precisely determined with a C.V. below 3%. The method was used to investigate the safety of reinfusion of drainage blood after knee and hip arthroplasty when ropivacaine (Naropin^®) was used for local analgesia. Data for 30 patients are summarised.     

Luminostat operation: a tool to maximize microalgae photosynthetic efficiency in photobioreactors during the daily light cycle?

The luminostat regime has been proposed as a way to maximize light absorption and thus to increase the microalgae photosynthetic efficiency within photobioreactors. In this study, simulated outdoor light conditions were applied to a lab-scale photobioreactor in order to evaluate the luminostat control under varying light conditions. The photon flux density leaving the reactor (PFD_out) was varied from 4 to 20 μmol photons m⁻² s⁻¹and the productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed.Maximal volumetric productivity (1.22 g kg⁻¹ d⁻¹) and biomass yield on PAR photons (400-700 nm) absorbed (1.27 g mol⁻¹) were found when PFD_out was maintained between 4 and 6 μmol photons m⁻² s⁻¹. The resultant photosynthetic efficiency was comparable to that already reported in a chemostat-controlled reactor. A strict luminostat regime could not be maintained under varying light conditions. Further modifications to the luminostat control are required before application under outdoor conditions.     

Tradeoffs between metabolic rate and spiracular conductance in discontinuous gas exchange of Samia cynthia (Lepidoptera, Saturniidae)

The insect tracheal system is a unique respiratory system, designed for maximum oxygen delivery at high metabolic demands, e.g. during activity and at high ambient temperatures. Therefore, large safety margins are required for tracheal and spiracular conductance. Spiracles are the entry to the tracheal system and play an important role in controlling discontinuous gas exchange (DGC) between tracheal system and atmosphere in moth pupae. We investigated the effect of modulated metabolic rate (by changing ambient temperature) and modulated spiracular conductance (by blocking all except one spiracles) on gas exchange patterns in Samia pupae. Both, spiracle blocking and metabolic rates, affected respiratory behavior in Samia cynthia pupae. While animals showed discontinuous gas exchange cycles at lower temperatures with unblocked spiracles, the respiratory patterns were cyclic at higher temperatures, with partly blocked spiracles or a combination of these two factors. The threshold for the transition from a discontinuous (DGC) to a cyclic gas exchange (^cycGE) was significantly higher in animals with unblocked spiracles (18.7 nmol g⁻¹ min⁻¹ vs. 7.9 nmol g⁻¹ min⁻¹). These findings indicate an important influence of spiracle conductance on the DGC, which may occur mostly in insects showing high spiracular conductances and low metabolic rates.     

The effects of rose hip (Rosa canina) on plasma antioxidative activity and C-reactive protein in patients with rheumatoid arthritis and normal controls: A prospective cohort study

Objectives

Rose hip (Rosa canina) has been used as an herbal remedy against a wide range of ailments including inflammatory disorders. The anti-inflammatory and antioxidant properties of rose hips have been evaluated in vitro and active constituents have been isolated. Rose hip contains antioxidant nutrients and an anti-inflammatory galactolipid. Rheumatoid arthritis (RA) is an inflammatory disease where activated cells release reactive oxygen substances. Thus it could be relevant to investigate if rose hip had an anti-inflammatory and/or antioxidant effect in this situation.

Methods

In this open case-control study 20 female patients with RA and 10 female controls were given 10.5 g rose hip powder daily (Litozin^®) for 28 days. Blood samples were analysed at baseline and follow-up for the capacity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase and the inflammatory marker C-reactive protein (CRP). The participants kept a food diary for the first 3 days and the last 3 days of the intervention period. The RA-patients completed The Stanford Health Assessment Questionnaire at baseline and follow-up.

Results

CRP-concentrations of both patients and healthy controls did not change. Nor was any effect found on the activity of antioxidant enzymes. There was no difference in food intake at baseline, but in the last week the RA-group reduced their energy intake.

Conclusions

10.5 g Litozin^® in 28 days had neither effect on clinical symptoms or laboratory measurements in patients with RA or healthy controls. This is in contrast to previous intervention studies with rose hip powder that found a reduction in the concentration of CRP. The results of the present study indicate that a daily amount of approximately 10 g rose hip powder for one month has no anti-inflammatory and/or antioxidant effect.     

Determination of the excitation migration time in Photosystem II: Consequences for the membrane organization and charge separation parameters

The fluorescence decay kinetics of Photosystem II (PSII) membranes from spinach with open reaction centers (RCs), were compared after exciting at 420 and 484 nm. These wavelengths lead to preferential excitation of chlorophyll (Chl) a and Chl b, respectively, which causes different initial excited-state populations in the inner and outer antenna system. The non-exponential fluorescence decay appears to be 4.3 ± 1.8 ps slower upon 484 nm excitation for preparations that contain on average 2.45 LHCII (light-harvesting complex II) trimers per reaction center. Using a recently introduced coarse-grained model it can be concluded that the average migration time of an electronic excitation towards the RC contributes ~ 23% to the overall average trapping time. The migration time appears to be approximately two times faster than expected based on previous ultrafast transient absorption and fluorescence measurements. It is concluded that excitation energy transfer in PSII follows specific energy transfer pathways that require an optimized organization of the antenna complexes with respect to each other. Within the context of the coarse-grained model it can be calculated that the rate of primary charge separation of the RC is (5.5 ± 0.4 ps)^− 1, the rate of secondary charge separation is (137 ± 5 ps)^− 1 and the drop in free energy upon primary charge separation is 826 ± 30 cm^− 1. These parameters are in rather good agreement with recently published results on isolated core complexes [Y. Miloslavina, M. Szczepaniak, M.G. Muller, J. Sander, M. Nowaczyk, M. Rögner, A.R. Holzwarth, Charge separation kinetics in intact Photosystem II core particles is trap-limited. A picosecond fluorescence study, Biochemistry 45 (2006) 2436-2442].