Word-specific cortical activity as revealed by the mismatch negativity

Neurophysiological brain activity evoked by individual spoken words and pseudowords was recorded and the mismatch negativity (MMN), an automatic index of experience-dependent auditory memory traces, was calculated. Consistent with earlier reported results, the MMN response to word-final syllables was enhanced compared with that elicited by the same syllables placed in a pseudoword context. Here we now demonstrate that the enhancement of the MMN elicited by two individual words showed different scalp topographies. The early word-specific brain activity is consistent with the assumption that the memory traces activated by individual words are carried by large neuronal ensembles that differ in their distributions over the cortex. Current source estimates localized the between-word differences in the right hemisphere and in parieto-occipital left-hemispheric areas. The differential brain responses to individual words appeared as early as ∼100 ms after the recognition points of the words, suggesting that their specific memory traces become active almost immediately after the information in the acoustic input is sufficient for word identification.     

Physical loading and performance as predictors of back pain in healthy adults A 5-year prospective study

We investigated muscle strength, aerobic power, and occupational and leisure-time physical loading as predictors of back pain in a 5-year follow-up study. A cohort of 456 adults aged 25, 35, 45 and 55 years, free of back pain, participated in measurements of anthropometric characteristics, aerobic power and muscle strength characteristics at baseline. The subjects' levels and types of physical activity and occupational physical loading were also determined. At 5 years after the baseline examinations 356 of these subjects (78.1 %) were reached by mail, and 262 of them (73.6%) properly completed and returned a questionnaire including a detailed back pain history for the 5 years following the baseline measurements. Of this number 56 subjects (21 %) who reported back pain ( > 30 on a scale from 0 to 100) and functional impairment during the 5-year follow-up composed the marked back pain group. Other subjects (n = 71, 27%) noting lesser symptoms were included in the mild back pain group; 135 subjects (52%) reported having had no back pain. The subjects with marked back pain were on average taller than the subjects without back pain, while no such difference was found in body mass. Heavy occupational musculoskeletal loading (P = 0.005) and high general occupational physical demands (P = 0.036) predicted future back pain. Leisuretime physical activity, aerobic power or muscle strength characteristics were not predictive of future back pain.     

Evidence for exercise therapy in the treatment of chronic disease based on at least three randomized controlled trials--summary of published systematic reviews

Final evidence for the overall benefits of exercise therapy in the treatment/rehabilitation of specific chronic disease comes from randomized controlled trials (RCTs). This paper summarizes current evidence that is based on a systematic review including data from at least three RCTs with contrast for exercise only. The quality of specific RCTs as well as the quality of systematic reviews varies, the newest ones usually being of higher quality than the older ones. The most consistent finding of the studies is that aerobic capacity and muscular strength of patients can be improved without causing detrimental effects on disease progression. Severe complications during these carefully tailored programs were rare. The treatment periods and follow-up times of the majority of the RCTs are of a too short duration to document group differences in disease progression. However, exercise reduces disease-related symptoms in many diseases, such as osteoarthritis, asthma and chronic obstructive pulmonary disorder. Also, RCTs studying patients with coronary heart disease as well as patients with heart failure show that all-cause mortality is lower in exercisers than in controls.     

Occurrence of chronic disease in former top-level athletes. Predominance of benefits,risks or selection effects?

Former elite athletes from most sports disciplines have lower overall morbidity risk and enjoy better self-rated health in later years compared with the general population and matched controls who were healthy at young age. This is seen particularly among former endurance athletes who have a lower incidence of coronary heart disease and type 2 diabetes mellitus. Most often data are available only for men. Based on the available data, participation in elite sports cannot be regarded as an overall health hazard. However, aside from a high risk of acute injury in specific sports, possible negative effects of long-standing athletic activity on the development of osteoarthritis should not be neglected. It should also be remembered that elite athletes are a biologically and genetically select group who are not representative of the population at large. Given the nature of the available data, the possible health consequences of recent changes in different characteristics of sports, such as training practices, professionalism and use of doping, cannot be properly predicted.     

Lower limb asymmetry and patellofemoral joint incongruence in the etiology of knee exertion injuries in athletes

The association between different knee exertion injuries and lower limb malalignments was studied in 121 male athletes with knee exertion injuries and in 20 male athletes without knee symptoms. The associations between different malalignments was also analyzed. Leg length inequality (LLI), knee valgus, and different indexes of patellofemoral joint congruence were measured using radiological methods. Male athletes with patellar apicitis (n = 59) had significantly more LLI (P less than 0.001) and patella alta (P less than 0.05) than athletes without knee symptoms. The knee valgus was of the same numerical value in the shorter and longer leg sides in subjects with LLI of at least 5 mm (n = 58). A positive correlation was found between lateral patellar displacement (LPD) and patella alta (LT/LP) (P less than 0.001). Negative correlations were found between the sulcus angle (SA) and the lateral patello-femoral angle (LPA) (P less than 0.001) as well as between the LPD and the LPA (P less than 0.001).     

Differential regulation of basolateral Cl-/HCO3- exchangers SLC26A7 and AE1 in kidney outer medullary collecting duct

SLC26A7 is a recently identified Cl(-)/HCO(3)(-) exchanger that co-localizes with AE1 on the basolateral membrane of Alpha intercalated cells (A-IC) in outer medullary collecting duct (OMCD). The purpose of these studies was to determine whether AE1 and SLC26A7 are differentially regulated in OMCD in pathophysiologic states. Toward this end, the expression and regulation of AE1 and SLC26A7 was examined in water deprivation, a condition known to increase the osmolality of the medulla. Rats were subjected to 3 d of water deprivation while having free access to food. Northern hybridizations demonstrated that in the outer medulla, the mRNA expression of SLC26A7 increased by approximately 300% (P < 0.01 versus control; n = 3), whereas the expression of AE1 decreased by approximately 50% (P < 0.05 versus control, n = 3) in water-deprived rats. Immunoblot analysis studies demonstrated that in the outer medulla, SLC26A7 abundance increased by approximately 3.5-fold (P < 0.02 versus control; n = 3), whereas the AE1 abundance decreased by approximately 55% (P < 0.05 versus control) in water deprivation. The expression of SLC26A7 remained unchanged in the kidney cortex and stomach in water deprivation, indicating the specificity of SLC26A7 upregulation in outer medulla. In situ hybridization indicated the exclusive expression of SLC26A7 in the outer medulla and double immunofluorescence labeling confirmed the co-localization of AE1 and SLC26A7 on the basolateral membrane of A-IC cells in OMCD. It is concluded that AE1 and SLC26A7 are differentially regulated in OMCD in water deprivation. On the basis of these results and previous functional studies indicating the activation of SLC26A7 activity by high osmolality, it is proposed that SLC26A7 may play an important role in bicarbonate reabsorption and or cell volume regulation in OMCD (specifically under hypertonic conditions).     

Familial resemblance and diversity in bone mass and strength in the population are established during the first year of postnatal life

Familial resemblance and diversity in bone structure and strength in adulthood are determined in part during growth. Whether these characteristics are established during gestation or shortly after birth is not known. Total‐body, lumbar spine, and femoral neck size and mass and indices of tibial bending strength and distal radial compressive strength were measured using bone densitometry and quantitative computed tomography in 236 girls at 18.5 years of age. Among them, 219, 141, and 105 girls had crown‐heel length (CHL) and weight recorded at birth and at 6 and 12 months of age, and then height and weight were recorded at 3, 5, 10, 13, and 15 years of age in 181, 176, 127, 111, and 228 girls, respectively. Of these girls, 101 and 93 girls also had bone structure assessed at 11 and 13 years of age, respectively. Similar bone measurements were made once in 78 mother‐father pairs. CHL and weight at birth did not correlate or did so weakly with bone traits in girls at 18 years of age. By contrast, CHL at 6 months correlated with the height, bone traits, and strength at puberty and at 18 years of age (r = 0.24–0.56, p < .001) in girls and with their parents' height and bone traits (r = 0.15–0.37, p < .05). When the girls' CHL at 6 months was stratified into quartiles, the absolute and relative differences in bone traits observed at puberty (～11.5 years) were maintained as these traits tracked during the ensuing 7 years. Similarly, weight at 6 months correlated with the girls' bone traits at puberty and 18 years of age (r = 0.22–0.55, p < .05). During puberty and at 18 years of age, the girls' bone traits correlated with the corresponding traits in their parents (r = 0.32–0.43, p < .01). It is concluded that familial resemblance in bone structural strength and the position of an individual's bone traits relative to others in adulthood are likely to be established during the first year of life. Thus susceptibility to bone fragility late in life has its antecedents established early in life. © 2010 American Society for Bone and Mineral Research     

Acute injuries in Finnish junior floorball league players

Objectives

To investigate the incidence and characteristics of acute time-loss injuries in Finnish junior floorball league players.

Magnetic resonance imaging of patellofemoral relationships

Patellofemoral relationships were analyzed in 11 patients (13 knees) with patellar dislocation and 15 asymptomatic subjects (15 knees) at 0° and 20° of flexion. The measurements were made from five consecutive axial images through the patellofemoral joint. The six indices measured were lateral patellar tilt (LPT), lateral patellofemoral angle (LPA), lateral patellar displacement (LPD), patella-lateral condyle index (L/PW), congruence angle (CA), and sulcus angle (SA). The reproducibility of the method was evaluated. The difference between the two study groups was more evident at 0° than at 20° of knee flexion. Significant differences were noted between measurements made at different levels of the joint, particularly in the controls. Isometric contraction of the quadriceps muscle lateralized and tilted the patella slightly in both groups. L/PW with and without quadriceps muscle contraction, and LPA with reference to the anterior condyles differentiated between the two study groups most clearly. LPT and LPA with reference to the anterior condyles differentiated the study groups better than LPT and LPA with reference to the posterior condyles. The reproducibility was good except for inter-observer comparison of CA and SA. The use of an imaging plane selected at the midpoint of the patellar articular cartilage increases the sensitivity of the measurements, since it takes into account both the height of the patella and the tendency towards lateralization. These results indicate that patellar tilt is best measured with the LPA index and patellar lateralization with the L/PW index at 0° knee flexion. This study should always include isometric contraction of the quadriceps muscle.