Physical fitness in relation to later body composition in pre-school children

Objectives

Although physical fitness is considered a marker of health in youth, little is known whether physical fitness in pre-school age is related to later body composition. Thus, this study investigated (i) associations of physical fitness at 4.5 years of age with body composition 12 months later and (ii) whether improvements in physical fitness during the 12-month follow-up were associated with changes in body composition.

Hypodontia and retention of third molars in Norwegian medieval skeletons: dental radiography in osteoarchaeology

Objectives: The objective of the present study is to compare the prevalence of third molar hypodontia in matched medieval and modern Norwegian sample with the aim to examine whether there are secular changes in dental anomalies. A second objective is to determine the level of primary retention of third molar in the medieval sample.

Material and methods: The medieval material consisted of 130 adult skulls, hypodontia of third molars was determined using radiography and compared to findings with panoramic film images of 400 15-year-old individuals from a contemporary Norwegian epidemiological study.

Results: Among 130 medieval skulls, hypodontia of third molar was found in 36 skulls (27.7%), and in the contemporary sample, hypodontia of third molar was found in 69 individuals (17.2%). Female predominance, although not statistically significant, was observed both in the medieval and in the contemporary group. The third molars showed absence in the mandible (21.5%) more often than the maxilla in the medieval sample, and in both jaws (11.2%) in the contemporary material. In the medieval sample, only 7.7% of the individuals had at least one retained third molar.

Conclusion: No increase in the frequency of third molar hypodontia was found from the medieval period until today. The frequency of retained third molars seems to have increased from the medieval period to modern times. The use of radiographic examination in addition to macroscopic inspection can give us a better understanding of the aetiology on a number of conditions in human skeletal remains.     

Adaptation of human skeletal muscle to endurance training of long duration

Summary. The aim of this study was to examine the adaptive response of skeletal muscle to dynamic training of long duration and low intensity. The response of m. triceps brachii, (TB) and m. quadriceps femoris, vastus lateralis (VL) to training of long duration at an intensity corresponding to approximately 45% of V?O₂, max, has been studied in six subjects. Muscle specimens were taken during training (18.5 miles (30 km)), which involved skiing with a backpack, (6 daydweek, 8 weeks), as well as during a subsequent period of detraining (33 weeks). Increases in oxidative enzyme activities and capillarization during training were limited to the TB. There were parallel increases in citrate synthase (CS) and malate dehydrogenase (MDH) during the first 3 weeks of training (30%). CS then continued to rise (to 90% above pretraining level), while the increase in MDH levelled off. The activity of 3–hydroxyacyl-CoA-dehydrogenase (HAD) and the number of capillaries per fibre increased by 50 % and 40 % respectively. A selective decrease (12%) in area of fibre type IIA was noted during training after a 2-week period of energy deficiency. During the first 6 weeks of detraining, the decrease in CS and HAD (30%) was greater than the decrease in capillaries per fibre (14%). It is concluded that prolonged duration of training is not, in itself, sufficient to elicit an adaptive response in the leg muscles, while a modest training effect was seen for the arm muscles. The finding emphasizes the importance of adequate intensity in physical training programmes.     

Evidence of increased platelet activation after thrombolysis in patients with acute myocardial infarction.

OBJECTIVE--To assess platelet activation after thrombolysis in patients with acute myocardial infarction. DESIGN--Platelet function was assessed by measurement of the in vivo synthesis of thromboxane by gas chromatography-mass spectrometry of thromboxane's major urinary metabolite, 2,3-dinor-thromboxane-B2. SETTING--Coronary care unit of Huddinge University Hospital. SUBJECTS--30 patients with acute myocardial infarction given either streptokinase 1.5 million units intravenously over one hour + 500 mg aspirin (n = 10), 500 mg aspirin (n = 10), or neither thrombolysis nor aspirin (n = 10). RESULTS--Patients treated by thrombolysis had a 20-fold increase in thromboxane formation during thrombolysis compared with control patients not treated by thrombolysis (p = 0.0001). Until two days after thrombolysis thromboxane production in patients treated with streptokinase did not decrease to a value comparable with patients treated with aspirin but not given thrombolysis. CONCLUSION--Thromboxane production increased considerably during thrombolysis, possibly reflecting greatly enhanced platelet activation. The slow decrease in thromboxane formation after treatment with aspirin suggests that the efficacy of thrombolysis might be improved by more efficient antiplatelet treatment.     

MYC inhibition induces metabolic changes leading to accumulation of lipid droplets in tumor cells

The MYC genes are the most frequently activated oncogenes in human tumors and are hence attractive therapeutic targets. MYCN amplification leads to poor clinical outcome in childhood neuroblastoma, yet strategies to modulate the function of MYCN do not exist. Here we show that 10058-F4, a characterized c-MYC/Max inhibitor, also targets the MYCN/Max interaction, leading to cell cycle arrest, apoptosis, and neuronal differentiation in MYCN-amplified neuroblastoma cells and to increased survival of MYCN transgenic mice. We also report the discovery that inhibition of MYC is accompanied by accumulation of intracellular lipid droplets in tumor cells as a direct consequence of mitochondrial dysfunction. This study expands on the current knowledge of how MYC proteins control the metabolic reprogramming of cancer cells, especially highlighting lipid metabolism and the respiratory chain as important pathways involved in neuroblastoma pathogenesis. Together our data support direct MYC inhibition as a promising strategy for the treatment of MYC-driven tumors.     

Glucose Homeostasis Variables in Pregnancy versus Maternal and Infant Body Composition

Intrauterine factors influence infant size and body composition but the mechanisms involved are to a large extent unknown. We studied relationships between the body composition of pregnant women and variables related to their glucose homeostasis, i.e., glucose, HOMA-IR (homeostasis model assessment-insulin resistance), hemoglobin A_1c and IGFBP-1 (insulin-like growth factor binding protein-1), and related these variables to the body composition of their infants. Body composition of 209 women in gestational week 32 and of their healthy, singleton and full-term one-week-old infants was measured using air displacement plethysmography. Glucose homeostasis variables were assessed in gestational week 32. HOMA-IR was positively related to fat mass index and fat mass (r² = 0.32, p < 0.001) of the women. Maternal glucose and HOMA-IR values were positively (p ≤ 0.006) associated, while IGFBP-1was negatively (p = 0.001) associated, with infant fat mass. HOMA-IR was positively associated with fat mass of daughters (p < 0.001), but not of sons (p = 0.65) (Sex-interaction: p = 0.042). In conclusion, glucose homeostasis variables of pregnant women are related to their own body composition and to that of their infants. The results suggest that a previously identified relationship between fat mass of mothers and daughters is mediated by maternal insulin resistance.