The aim of this study was to investigate the relationship between heart rate variability (HRV) during exercise and ventilatory threshold (VT), using the MemCalc system which is superior in spectral analysis. Nine healthy male subjects with no cardiopulmonary disease performed an exercise test to exhaustion to determine VT on a bicycle ergometer. Low frequency (LF : 0.04-0.15 Hz), high frequency (HF : 0.15-0.40Hz) and LF/HF ratio power spectra were calculated by maximum entropy method (MEM) spectral analysis, using the MemCalc system. In each case, when the subject started exercise, the HF component declined rapidly during the first 30 seconds ; and compared to the resting value, it declined to approximately 5 % at VT. The possibility of using this phenomenon as a criterion for setting intensity of exercise is tinder consideration. The LF/HF ratio showed different patterns of variation among the subjects. A significant linear relationship was seen between the declining rate of the HF component and VT (r=0.93, p<0.001), suggesting a corres pondence between the heart's capability of adjusting to maintained exercise and high endurance capacity.

OBJECTIVE: A recent study suggested that rs6504340, a polymorphism within the homeobox B (HOXB) gene cluster, is associated with the susceptibility for malocclusions in Europeans. The resulting malocclusions require orthodontic treatment. The aim of this study was to investigate the association of rs6504340 and other dentition-implicated polymorphisms with dental and occlusal traits in Korean and Japanese populations. METHODS: The study participants included 223 unrelated Koreans from the Busan area and 256 unrelated Japanese individuals from the Tokyo metropolitan area. DNA samples were extracted from saliva specimens. Genotyping for rs6504340 and four single nucleotide polymorphisms (SNPs) that have been shown to be associated with the timing of first tooth eruption and the number of teeth at 1 year of age (rs10506525, rs1956529, rs9674544, and rs8079702) was performed using TaqMan assays. The Index of Orthodontic Treatment Need (IOTN), overjet, overbite, arch length discrepancy, crown sizes, and length and width of the dental arches were measured. Spearman's correlation coefficients were calculated to evaluate relationships between rs6504340 and these dental/occlusal traits. RESULTS: We evaluated the aesthetic components and dental health components of the IOTN in the Korean and Japanese populations and found that neither rs6504340 nor the other four SNPs showed any association with dental and occlusal traits in these East Asian populations. CONCLUSIONS: These negative results suggest that further research is needed to identify the genetic determinants of malocclusions in order to reach a consensus.
Asian Continental Ancestry Group* ; Busan ; Consensus ; Crowns ; Dental Arch ; DNA ; Genes, Homeobox ; Genetics ; Humans ; Index of Orthodontic Treatment Need ; Malocclusion ; Multigene Family ; Overbite ; Polymorphism, Single Nucleotide ; Saliva ; Tooth Eruption* ; Tooth*

LR11, also known as SorLA or SORL1, is a type-I membrane protein from which a large extracellular part, soluble LR11 (sLR11), is released by proteolytic shedding on cleavage with a disintegrin and metalloproteinase 17 (ADAM17). A shedding mechanism is presumed to have a key role in the functions of LR11, but the evidence for this has not yet been demonstrated. Tetraspanin CD9 has been recently shown to regulate the ADAM17-mediated shedding of tumor necrosis factor-alpha and intercellular adhesion molecule-1 on the cell surface. Here, we investigated the role of CD9 on the shedding of LR11 in leukocytes. LR11 was not expressed in THP-1 monocytes, but it was expressed and released in phorbol 12-myristate 13-acetate (PMA)-induced THP-1 macrophages (PMA/THP-1). Confocal microscopy showed colocalization of LR11 and CD9 proteins on the cell surface of PMA/THP-1. Ectopic neo-expression of CD9 in CCRF-SB cells, which are LR11-positive and CD9-negative, reduced the amount of sLR11 released from the cells. In contrast, incubation of LR11-transfected THP-1 cells with neutralizing anti-CD9 monoclonal antibodies increased the amount of sLR11 released from the cells. Likewise, the PMA-stimulated release of sLR11 increased in THP-1 cells transfected with CD9-targeted shRNAs, which was negated by treatment with the metalloproteinase inhibitor GM6001. These results suggest that the tetraspanin CD9 modulates the ADAM17-mediated shedding of LR11 in various leukemia cell lines and that the association between LR11 and CD9 on the cell surface has an important role in the ADAM17-mediated shedding mechanism.
ADAM Proteins/*metabolism ; Antigens, CD9/genetics/*metabolism ; Cell Line, Tumor ; Humans ; LDL-Receptor Related Proteins/genetics/*metabolism ; Leukocytes/*metabolism ; Macrophages/metabolism ; Membrane Transport Proteins/genetics/*metabolism ; Proteolysis