Extended physical education in children aged 6-15 years was associated with improved academic achievement in boys.

AIM: Physical activity (PA) has been associated with enhanced cognition, brain development and concentration. This study evaluated whether increased physical education (PE) improved academic achievement. METHODS: We recruited 304 children (55% boys) from a Swedish school in Skane County in 1998-2002 when they were six to seven years of age and followed them through all nine mandatory school years. Their PE level was increased from 60 to 200 minutes per week, and their results were compared with 73 885 control children (51% boys) in the county who graduated in the same years and did the standard 60 minutes of PE per week. Their academic achievements were measured as their final grade scores and the proportion of students eligible for upper secondary school. RESULTS: The eligibility for further education increased in the intervention boys by 6.8 percentage points and the mean grade score by 12.1 points, while in the control group as a whole, the eligibility rate decreased by 0.7 percentage points and the mean grade score increased by 1.7 points. No changes in eligibility rates or mean grade scores were seen in the intervention girls. CONCLUSION: Increasing weekly PE over nine years was associated with improved academic achievement in boys.

Low physical activity is related to clustering of risk factors for fracture-a 2-year prospective study in children.

The study investigates the effect of physical activity (PA) on a composite score for fracture risk in pre-pubertal children. Low PA in children is related to the composite score for fracture risk and the pre-pubertal years seem to be a period when PA positively affects the score. INTRODUCTION: This study evaluates if PA in children is related to clustering of risk factors for fracture. Research questions are the following: (i) What is the effect of physical activity (PA) on single traits and a composite score for fracture risk? (ii) Could this score be used to identify the level of PA needed to reach beneficial effects? METHODS: This prospective population-based study included 269 children, aged 7-9 years at baseline while 246 attended the 2-year follow-up. We estimated duration of PA by questionnaires and measured traits that independently predict fractures. We then calculated gender specific Z-scores for each variable. The mean Z-score of all traits was used as a composite score for fracture risk. We tested correlation between duration of PA, each trait, and the composite score and group differences between children in different quartiles of PA. RESULTS: At baseline, we found no correlation between duration of PA and any of the traits or the composite score. At follow-up, we found a correlation between PA and the composite score. Physical activity had an effect on composite score, and children in the lowest quartiles of PA had unbeneficial composite score compared to children in the other quartiles. CONCLUSION: Low PA in children is related to clustering of risk factors for fracture, and the pre-pubertal years seem to be a period when PA positively affects the composite score.

Recent hip fracture trends in Sweden and Denmark with age-period-cohort effects.

This study used nationwide hip fracture data from Denmark and Sweden during 1987-2010 to examine effects of (birth) cohort and period. We found that time trends, cohort, and period effects were different in the two countries. Results also indicated that hip fracture rates may increase in the not so far future. INTRODUCTION: The reasons for the downturn in hip fracture rates remain largely unclear but circumstances earlier in life seem important. METHODS: We ascertained hip fractures in the populations ≥50 years in Denmark and Sweden in national discharge registers. Country- and sex-specific age-period-cohort (APC) effects during 1987-2010 were evaluated by log-likelihood estimates in Poisson regression models presented as incidence rate ratios (IRR). RESULTS: There were 399,596 hip fractures in SE and 248,773 in DK. Age-standardized hip fracture rate was stable in SE men but decreased in SE women and in DK. Combined period + cohort effects were generally stronger in SE than DK and in women than men. IRR per period ranged from 1.05 to 1.30 in SE and 0.95 to 1.21 in DK. IRR per birth cohort ranged from 1.07 to 3.13 in SE and 0.77 to 1.67 in DK. Relative period effects decreased with successive period in SE and described a convex curve in DK. Relative cohort effects increased with successive birth cohort in both countries but with lower risks for DK women and men and SE women born around the 1930s (age 75-86 years today and responsible for most hip fractures) partly explaining the recent downturn. Men and women born thereafter however seem to have a higher hip fracture risk, and we expect a reversal of the present decline in rates, with increasing hip fracture rates in both Denmark and Sweden during the upcoming decade. CONCLUSIONS: Time trends, cohort, and period effects were different in SE and DK. This may reflect differences in general health as evident in known differences in life expectancy, healthcare organization, and prevention such as use of anti-osteoporosis drugs. Analyses indicate that hip fracture rates may increase in the not so far future.

Increased risk of hip fracture among spouses-evidence of a homogamy effect.

Spouses tend to share habits and therefore have an increased risk of same diseases. We followed all married couples in Sweden, born 1902 to 1942, in hospital records from 1987 to 2002, and found that individuals whose spouse had a hip fracture had an increased risk of hip fracture. INTRODUCTION: The purpose of this study was to determine whether spouses of hip fracture patients have an elevated risk of hip fracture. METHODS: We performed a retrospective cohort study of all couples married for at least 5 years in Sweden and born between 1902 and 1942 (n = 904,451) and all patients registered with a hip fracture (n = 218,285) in the National Inpatients Register in Sweden from 1987 to 2002. RESULTS: During the period 1987 to 2002 hip fractures occurred among spouses in 4212 married couples. The hazard ratio (HR) for hip fracture in a married woman following hip fracture in the husband was 1.11 (95 % confidence interval 1.07 to 1.16) compared to a woman whose husband did not have hip fracture. The corresponding HR for a married man was 1.20 (1.15 to 1.26) compared to a man whose wife did not have hip fracture. The risk was significantly elevated over the age range 60 to 90 years. The increased risk for hip fracture among spouses remained after adjustments for income, education, geographical latitude and urbanisation. In a common model with spouses and their siblings, the HR for spousal effect were 1.63 (1.01 to 2.64) and for sibling effect 2.18 (1.55 to 3.06) compared to married with spouse and sibling respectively without hip fracture. CONCLUSION: The novel finding of an increased risk for hip fracture among spouses provides evidence indicating that there is a homogamy effect due to common social and lifestyle factors but could also be due to assortative mating.

FRAX predicts incident falls in elderly men: findings from MrOs Sweden.

UNLABELLED: Falls and fractures share several common risk factors. Although past falls is not included as an input variable in the FRAX calculator, we demonstrate that FRAX probability predicts risk of incident falls in the MrOs Sweden cohort. INTRODUCTION: Although not included in the FRAX® algorithm, it is possible that increased falls risk is partly dependent on other risk factors that are incorporated into FRAX. The aim of the present study was to determine whether fracture probability generated by FRAX might also predict risk of incident falls and the extent that a falls history would add value to FRAX. METHODS: We studied the relationship between FRAX probabilities and risk of falls in 1836 elderly men recruited to the MrOS study, a population-based prospective cohort of men from Sweden. Baseline data included falls history, clinical risk factors, bone mineral density (BMD) at femoral neck, and calculated FRAX probabilities. Incident falls were captured during an average of 1.8 years of follow-up. An extension of Poisson regression was used to investigate the relationship between FRAX, other risk variables, and the time-to-event hazard function of falls. All associations were adjusted for age and time since baseline. RESULTS: At enrolment, 15.5 % of the men had fallen during the preceding 12 months (past falls) and 39 % experienced one or more falls during follow-up (incident falls). The risk of incident falls increased with increasing FRAX probabilities at baseline (hazard ratio (HR) per standard deviation (SD), 1.16; 95 % confidence interval (95%CI), 1.06 to 1.26). The association between incident falls and FRAX probability remained after adjustment for past falls (HR per SD, 1.12; 95%CI, 1.03 to 1.22). High compared with low baseline FRAX score (>15 vs <15 % probability of major osteoporotic fracture) was strongly predictive of increased falls risk (HR, 1.64; 95%CI, 1.36 to 1.97) and remained stable with time. Whereas past falls were a significant predictor of incident falls (HR, 2.75; 95%CI, 2.32 to 3.25), even after adjustment for FRAX, the hazard ratio decreased markedly with increasing follow-up time. CONCLUSIONS: Although falls are not included as an input variable, FRAX captures a component of risk for future falls and outperforms falls history with an extended follow-up time.

The associations of physical activity with fracture risk--a 7-year prospective controlled intervention study in 3534 children.

SUMMARY: This is the first study indicating an association between gradually diminished risk of fractures and years of increased physical activity. Our results could imply great benefits not only for the individual but also for the healthcare burden and cost of society. INTRODUCTION: Physical activity (PA) in childhood is associated with high bone mass and beneficial neuromuscular function. We investigate if increased PA also is associated with fracture risk. METHODS: We registered fractures in 3534 children aged 6 to 8 years at study start for up to 7 years; 1339 with 40 min of moderate PA every school day (intervention) and 2195 with the Swedish standard curriculum of 60 min of PA per school week (controls). In a subsample of 264 children, we measured areal bone mineral density (aBMD; g/cm(2)) with dual-energy X-ray absorptiometry (femoral neck and total spine) and muscle strength (peak torque for knee extension and flexion; Nm) with computerized dynamometer at baseline and after 7 years. We estimated annual fracture incidence rate ratios (IRR) in the intervention group compared to the control group as well as changes in bone mass and muscle strength. Data is given as mean (95% CI). RESULTS: The IRR of fractures decreased with each year of the PA intervention (r = -0.79; p = 0.04). During the seventh year, IRR was almost halved [IRR 0.52 (0.27, 1.01)]. The intervention group had a statistically significant greater gain in total spine aBMD with a mean group difference of 0.03 (0.00, 0.05) g/cm(2) and peak flexion torque 180° with a mean group difference of 5.0 (1.5, 8.6) Nm. CONCLUSIONS: Increased PA is associated with decreased fracture risk, probably in part due to beneficial gains in aBMD and muscle strength.

Surgery for adult acquired flatfoot due to posterior tibial tendon dysfunction reduces pain, improves function and health related quality of life.

BACKGROUND: Patients with adult acquired flatfoot deformity (AAFD) due to posterior tibial tendon dysfunction (PTTD) may require surgery but few reports have evaluated the outcome. METHODS: We evaluated 21 patients with a median age of 60 (range 37-72) years who underwent different surgical reconstructions due to stage II AAFD before and 6 and 24 months after surgery by the validated Self-Reported Foot and Ankle Score (SEFAS), Short Form 36 (SF-36) and Euroquol 5 Dimensions (EQ-5D). RESULTS: The improvement from before to 24 months after surgery was in SEFAS mean 12 (95% confidence interval 8-15), SF-36 physical function 21 (10-22), SF-36 bodily pain 28 (17-38), EQ-5D 0.2 (0.1-0.3) and EQ-VAS 11 (2-21). CONCLUSION: Surgery for AFFD due to PTTD results in reduced pain and improved function and health related quality of life. The outcome scores have been demonstrated as useful. It has also been shown, since there is a further improvement between 6 and 24 months after surgery, that a minimum follow-up of 2 years is needed. LEVEL OF CLINICAL EVIDENCE: III - prospective observational cohort study.

The number and characteristics of prevalent vertebral fractures in elderly men are associated with low bone mass and osteoporosis.

We sought to determine whether specific characteristics of vertebral fractures in elderly men are associated with low bone mineral density (BMD) and osteoporosis. Mister Osteoporosis Sweden is a population based cohort study involving 3014 men aged 69 to 81 years. Of these, 1427 had readable lateral radiographs of the thoracic and lumbar spine. Total body (TB) BMD (g/cm²) and total right hip (TH) BMD were measured by dual energy x-ray absorptiometry. The proportion of men with osteoporosis was calculated from TH BMD. There were 215 men (15.1%) with a vertebral fracture. Those with a fracture had lower TB BMD than those without (p < 0.001). Among men with a fracture, TB BMD was lower in those with more than three fractures (p = 0.02), those with biconcave fractures (p = 0.02) and those with vertebral body compression of > 42% (worst quartile) (p = 0.03). The mean odds ratio (OR) for having osteoporosis when having any type of vertebral fracture was 6.1 (95% confidence interval (CI) 3.9 to 9.5) compared with those without a fracture. A combination of more than three fractures and compression in the worst quartile had a mean OR of 114.2 (95% CI 6.7 to 1938.3) of having osteoporosis compared with those without a fracture. We recommend BMD studies to be undertaken in these subcohorts of elderly men with a vertebral fracture.

Exercise in youth: High bone mass, large bone size, and low fracture risk in old age.

Physical activity is favorable for peak bone mass but if the skeletal benefits remain and influence fracture risk in old age is debated. In a cross-sectional controlled mixed model design, we compared dual X-ray absorptiometry-derived bone mineral density (BMD) and bone size in 193 active and retired male elite soccer players and 280 controls, with duplicate measurements of the same individual done a mean 5 years apart. To evaluate lifetime fractures, we used a retrospective controlled study design in 397 retired male elite soccer players and 1368 controls. Differences in bone traits were evaluated by Student's t-test and fracture risk assessments by Poisson regression and Cox regression. More than 30 years after retirement from sports, the soccer players had a Z-score for total body BMD of 0.4 (0.1 to 0.6), leg BMD of 0.5 (0.2 to 0.8), and femoral neck area of 0.3 (0.0 to 0.5). The rate ratio for fracture after career end was 0.6 (0.4 to 0.9) and for any fragility fracture 0.4 (0.2 to 0.9). Exercise-associated bone trait benefits are found long term after retirement from sports together with a lower fracture risk. This indicates that physical activity in youth could reduce the burden of fragility fractures.

Groin pain and soccer players: male versus female occurrence.

AIM: Groin pain is common in soccer players. Comparison of results from different studies, especially between genders, is difficult as studies use different definitions and data collection procedures. Therefore we conducted a study of both male and female soccer players enabling direct gender comparison. METHODS: The study enrolled 479 male soccer players aged 25 years (17-43) (mean with range) and 144 female soccer players aged 23 years (16-47), who answered a mailed questionnaire that included specific questions on groin pain and sports history. Data are presented as proportions (%) or as mean with 95% confidence intervals (95% CI). RESULTS: Groin pain was experienced by 55% of male soccer players and 28% of female soccer players, resulting in an odds ratio (OR) of 2.9 (95% CI 1.9, 4.5). Groin pain occurred more often in the preseason, than during the rest of the season in both male and female players (both P<0.001). Playing position in the team or playing league did not seem to influence the risk of suffering groin pain. CONCLUSION: In soccer players, male gender and preseasonal training appear to be risk factors for developing groin pain.

Bone mass and anthropometry in patients with osteoarthritis of the foot and ankle.

BACKGROUND: Patients with hip and knee osteoarthritis (OA) have high bone mineral density (BMD) and high BMI. If the same accounts for patients with foot or ankle OA is unknown. METHODS: We measured BMD and femoral neck (FN) width by dual-energy X-ray absorptiometry in 42 women and 19 men with idiopathic OA in the foot or ankle, and in 99 women and 82 men as controls. RESULTS: Women with OA had significant higher BMI than controls. Women with OA had higher BMI-adjusted BMD (p<0.01) and smaller BMI-adjusted FN width (p<0.01) than controls. Men with OA had higher BMI adjusted-BMD (p<0.05) and smaller BMI-adjusted FN width (p<0.01) than controls. CONCLUSION: Patients with OA in the foot or ankle have higher BMD and smaller bone size than being expected by their BMI. This phenotype may provide unfavourable forces across the joint and is hypothetically important for development of OA.

Prevention of falls in the elderly--a review.

The proportion of elderly in the society increases and fall frequency increases with advancing age. Many falls result in fractures and also soft tissue injuries, longstanding pain, functional impairment, reduced quality of life, increased mortality, and excess in healthcare costs. Due to the magnitude of these negative effects, a variety of single- and multicomponent fall-preventive intervention programs has been initiated.This review identifies programs that, in randomized controlled trials (RCTs), have been shown with fall-reductive effects.The most effective strategies in community-dwelling elderly include regular physical training with program that includes several different training modalities. Modification of the overall or patient-specific risk factor profile in home hazard modification program has been proven to decrease fall risk in community-living elderly. The elderly in the community benefit also from wearing antislip shoe devices when walking in icy conditions, from adjustment of psychotropic medication, and from structured modification of multipharmacy. If vitamin D levels in blood are low, supplementation is beneficial as is the first eye cataract surgery and pacemaker implantation in patients with cardioinhibitory carotid sinus hypersensitivity. In addition to modification of specific risk factors, generalized and individualized multifactorial preventive programs, all including some sort of physical training, have been found to decrease the fall risk. In summary, there is now strong evidence in the literature that structured fall-preventive programs in the elderly, especially in high-risk groups, are beneficial in reducing both the number of fallers and the number of falls in community.

Bone mass following physical activity in young years: a mean 39-year prospective controlled study in men.

UNLABELLED: This is a study on exercise-associated bone mineral density (BMD) which in men is maintained three decades after cessation of sports. In this prospective controlled cohort study active athletes had a BMD Z-score of 1.0 and after 39 years 0.5 to 1.2 depending on the measured region), using the same single-photon absorptiometry device, dual X-ray absorptiometry (DXA), and peripheral computed tomography (pQCT). INTRODUCTION: The aims of this study were to prospectively evaluate BMD changes in male athletes from activity into long-term retirement and to simultaneously evaluate other bone traits. METHODS: Bone mineral density (grams per square centimeter) was measured in 46 male athletes with a mean age of 22 years (range, 15-40) by using the same single-photon absorptiometry device, both at active career and a mean of 39 years (range, 38-40) later when they had long-term retired. At follow-up, BMD was also evaluated by DXA and pQCT. Twenty-four non-athletic males of similar age served as controls. Between-group differences are presented as means with 95% confidence intervals. RESULTS: The active athletes (baseline) had a BMD Z-score of 1.0 (0.7, 1.4) in the femoral condyles. The retired athletes (follow-up) had a BMD Z-score of 0.5 to 1.2 depending on the measuring technique and the measured region. The tibial cortical area Z-score at follow-up was 0.8 (0.5, 1.2) and the tibial strength index Z-score 0.7 (0.4, 1.0). There were no changes in BMD Z-scores from activity to retirement, neither when estimated by the same device in different regions [∆ Z-score -0.3 (-0.8, 0.2)] nor in the same region with different devices [∆ Z-score 0.0 (-0.4, 0.4)]. The benefits remained after adjustments for anthropometrics and lifestyle. No correlation was seen with years since retirement. CONCLUSIONS: Exercise-associated high BMD in young years seems, in men, to be maintained three decades after cessation of high-level physical activity.

Training and bone - from health to injury.

Mechanical load through physical activity has been shown to be one of the best stimuli to increase the bone strength. This effect of mechanical load accounts for both the accrual of bone mineral and structural skeletal adaptations. Exercise prescription also includes a "window of opportunity" in the late pre- and early peri-pubertal period, where exercise is supposed to insert the most obvious beneficial effects, even if physical activity provides recordable skeletal benefits during all growth. There is also evidence that benefits in bone mass and bone structure obtained by mechanical load during growth may be maintained at advanced age. The notion that former male athletes have lower fracture risk than expected by age, support this view. Physical activity could therefore to be recommended at growth and adolescence as one possible strategy to reduce the future burden of fragility fractures.

Increased lipolysis by secretory phospholipase A(2) group V of lipoproteins in diabetic dyslipidaemia.

BACKGROUND: Lipolysis of lipoproteins by secretory phospholipase A(2) group V (sPLA(2)-V) promotes inflammation, lipoprotein aggregation and foam cell formation--all considered as atherogenic mechanisms. OBJECTIVE: In this study, we compared the susceptibility to sPLA(2)-V lipolysis of VLDL and LDL from individuals with type 2 diabetes and the metabolic syndrome (T2D-MetS) and from healthy controls. Design. VLDL and LDL were isolated from 38 T2D-MetS subjects and 38 controls, treated pair-wise. Extent of sPLA(2)-V lipolysis was measured as release of nonesterified free fatty acids (NEFA). In a subset of the subjects, lipoprotein composition was determined as a relationship between lipid and apolipoprotein components. RESULTS: Mean paired increase in sPLA(2)-V lipolysis after 1 h for T2D-MetS versus control was 2.0 micromol NEFA l(-1) for VLDL (P = 0.004) and 0.75 micromol NEFA l(-1) for LDL (P = 0.001). There were also substantial differences in lipoprotein composition between the groups. T2D-MetS VLDL had higher triglyceride and cholesterol contents than control VLDL. T2D-MetS LDL was smaller and contained more triglycerides and less cholesterol than control LDL. Both VLDL and LDL from T2D-MetS subjects also contained more apolipoprotein CIII per particle. CONCLUSION: VLDL and LDL from T2D-MetS individuals were more susceptible to sPLA(2)-V lipolysis than those from control individuals. This may result in elevated levels of NEFA and lysophosphatidylcholine, both in circulation and in LDL, possibly contributing to the elevated inflammatory state and increased risk of cardiovascular diseases seen in these individuals.

The peritoneal microcirculation in peritoneal dialysis.

This paper deals with the peritoneal microcirculation and with peritoneal exchange occurring in peritoneal dialysis (PD). The capillary wall is a major barrier to solute and water exchange across the peritoneal membrane. There is a bimodal size-selectivity of solute transport between blood and the peritoneal cavity, through pores of radius approximately 40-50 A as well as through a very low number of large pores of radius approximately 250 A. Furthermore, during glucose-induced osmosis during PD, nearly 40% of the total osmotic water flow occurs through molecular water channels, termed "aquaporin-1." This causes an inequality between 1 - sigma and the sieving coefficient for small solutes, which is a key feature of the "three-pore model" of peritoneal transport. The peritoneal interstitium, coupled in series with the capillary walls, markedly modifies small-solute transport and makes large-solute transport asymmetric. Thus, although severely restricted in the blood-to-peritoneal direction, the absorption of large solutes from the peritoneal cavity occurs at a high clearance rate ( approximately 1 mL/min), largely independent of molecular radius. True absorption of macromolecules to the blood via lymphatics, however, seems to be occurring at a rate of approximately 0.2 mL/min. Several controversial issues regarding transcapillary and transperitoneal exchange mechanisms are discussed in this paper.

Transcytosis inhibitor N-ethylmaleimide increases microvascular permeability in rat muscle.

N-ethylmaleimide (NEM) has been claimed to markedly inhibit the transvascular passage of small proteins and albumin by interacting with the docking and fusion of plasmalemmal vesicles with their target membranes. To investigate the role of transcytosis in the transcapillary passage of albumin, we assessed the effects of NEM on (125)I-labeled radioiodinated serum albumin clearance (RISA-Cl) from blood to muscle in isolated and maximally vasodilated perfused rat hindquarters, in which vascular pressures, pre- and postcapillary resistances, and the capillary filtration coefficient (CFC) were continuously monitored. NEM (0.3-0.5 mM) caused a marked increase mainly in precapillary vascular resistance. Thus the arterial-to-venous resistance ratio in NEM-treated animals was 3.12 +/- 0.56 versus 1.66 +/- 0.17 during the control period (P < 0.05). Despite that, there was a doubling of both CFC from 0.0363 +/- 0.0028 to 0.0778 +/- 0.0101 ml x min(-1) x mmHg(-1) x 100 g(-1) (P < 0.01) and RISA-Cl, compared with the control situation, signaling markedly increased microvascular permeability. Our results strongly suggest that NEM, besides producing marked vasoconstriction, also causes damage to the capillary endothelium. Thus, instead of inhibiting transvascular transport, NEM may induce increases in the bulk transport of albumin from blood to tissue.

Hyaluronan and peritoneal ultrafiltration: a test of the "filter-cake" hypothesis.

Adding hyaluronan (HA) to the dialysis fluid seems to improve the efficiency of peritoneal dialysis (PD). This effect may be explained by the gradual formation of a HA "filter-cake" that decreases the tissue hydraulic conductivity. A filter cake (concentration hyperpolarization layer) can be formed when a large, slowly diffusible molecule, such as HA, is partly sieved by the pores of a membrane during the process of transmembrane ultrafiltration. The filter cake then forms at the "uphill" membrane-fluid interface, thereby increasing the resistance to fluid flow across the membrane. To test the filter-cake hypothesis, we investigated the effects of intraperitoneal (IP) HA on peritoneal small solute and water transport by administering HA either during the dwells or as incubations before PD dwells in rats. In the first set of experiments, HA, 0.01% (n = 7), 0.05% (n = 6), and 0.1% (n = 7) was given in 20 mL dialysis fluid (3.86% Dianeal). Control group was instilled with 20 mL of dialysis fluid. Evans Blue (EB) albumin was given as an intra-arterial (IA) bolus and (51)Cr-EDTA as an intravenous (IV) infusion. Plasma and dialysate were sampled up to 240 minutes to determine total peritoneal clearance (Cl), clearance from dialysate to plasma (Cl-->P) of (125)I-albumin (RISA), clearance from plasma to dialysate (Cl-->D) of EB-albumin, and mass transfer area coefficients (MTAC or permeability-surface area products, PS) of (51)Cr-EDTA and glucose. Peritoneal ultrafiltration (UF) was determined from RISA dilution. In the second set of experiments, rats were first incubated with 4 mL of phosphate-buffered saline (PBS) or PBS containing 0.1% HA for 120 minutes. Rats were then dialyzed with HA-free PD fluid, and sampling of plasma and dialysate was performed for 60 minutes. For HA concentrations exceeding 0.01%, UF volumes increased with increasing doses of HA. Small solute MTACs and initial UF were unaffected when HA was either given during the dwell or as a preincubation. Compared with control, there was a significant decrease in RISA-Cl for 0.05% HA and 0.1% HA. Also, Cl-->P decreased significantly compared with control for 0.1% HA. In conclusion, the present data clearly demonstrate that small solute MTACs and the glucose-induced osmotic water transport occurring early in the dwell are not affected by HA. Only the back-filtration of fluid from peritoneum to plasma was affected.

Silicon diodes as detectors for backscatter radiation in photon fields.

We investigated the use of unencapsulated silicon semiconductor detectors for backscatter radiation detection. The results were compared with Monte Carlo (MC) calculations modelling the experimental set-up. A special diode was manufactured, which was designed so that it allowed the positioning of different materials in close contact with the detector surface. Polymethylmethacrylate (PMMA), Pb, Ti and Fe (stainless steel) were used as backscatter materials. The diode signal was measured by integrating the current when irradiating the diode with an equal photon fluence obtained from a medical Co-60 source. When compared to the signal with PMMA as backscatter material the increase in signal was 21%, 27% and 73% for Ti, Fe and Pb, respectively. This is in reasonable agreement with the MC calculations, when taking the effective measurement depth in the Si diode detector into account.