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Group-A Xeroderma pigmentosum (XPA) proteins save mice from carcinogenesis due to chemicals and ultraviolet radiation, as revealed by the studies of XPA gene-deficient mice. XPA gene-deficient mice showed high susceptibility to chemical carcinogens and ultraviolet radiation, whereas no physical alterations and pathological changes were observed in the mice. The potential of XPA-deficient mice as in vivo models for studying high rates of skin cancers in Group-A Xeroderma pigmentosum patients is discussed.

Nucleotide excision repair is a versatile strategy for removing DNA damage from the genome. Tremendous progress in understanding this process has been made in the last few years, and the field continues to develop rapidly. Exciting connections have emerged between nucleotide excision repair, transcription, and DNA replication, but many mysteries remain concerning the biochemical details of the mechanism, the connection with several human inherited syndromes, and the role of DNA repair in preventing cancer.

Abstract Background The purpose of this study was to reveal any association between cardiorespiratory fitness level and excess post-exercise oxygen consumption (EPOC) using three cycling protocols with varying degrees of exercise intensity, i.e., sprint interval training (SIT), high-intensity interval aerobic training (HIAT), and continuous aerobic training (CAT). Findings Ten healthy men, aged 20 to 31 years, attended a cross-over experiment and completed three exercise sessions: SIT consisting of 7 sets of 30-s cycling at 120% VO2max with a 15-s rest between sets; HIAT consisting of 3 sets of 3-min cycling at 80~90% VO2max with a 2-min active rest at 50% VO2max between sets; and CAT consisting of 40 min of cycling at 60~65% VO2max. During each session, resting VO2, exercise VO2, and a 180-min post-exercise VO2 were measured. The net exercise VO2 during the SIT, HIAT, and CAT averaged 14.7 ± 1.5, 31.8 ± 4.1, and 71.1 ± 10.0 L, and the EPOCs averaged 6.8 ± 4.0, 4.5 ± 3.3, and 2.9 ± 2.8 L, respectively. The EPOC with SIT was greater than with CAT (P < 0.01) and HIAT (P = 0.12). Correlation coefficients obtained between subjects’ VO2max and the ratio of EPOC to net exercise VO2 for SIT, HIAT, and CAT were −0.61 (P = 0.06), -0.79 (P < 0.01), and −0.42 (P = 0.23), respectively. Conclusions Our data suggest that cardiorespiratory fitness level correlates negatively with the magnitude of EPOC, especially when performing aerobic-type interval training.

Xeroderma pigmentosum (XP) is a genetic disorder characterized by a high incidence of skin cancers, including malignant melanoma, which is often fatal. The genetic disorder is a defect in DNA repair mechanisms such that cells of XP patients are abnormally sensitive to sunlight. To identify the abnormal genetic sequence in XP patients, investigation of a candidate gene, XPAC, was carried out. This gene was added to cells from group A XP patients, and when the cells were subjected to ultraviolet light, they became ultraviolet-resistant. Cells from other XP types could not be made ultraviolet-resistant in this manner, indicating that the defect in XPAC distinguishes group A XP. The base sequence of XPAC was determined; preliminary results indicate that some proteins expressed by the gene are absent in group A XP cells, but not in those that were ultraviolet-resistant. Details regarding the structure of the XPAC protein are provided. (Consumer Summary produced by Reliance Medical Information, Inc.)

Abstract Background Although the measurement site at L4–L5 for visceral adipose tissue (VAT) has been commonly accepted, some researchers suggest that additional upper sites (i.e., L1–L2 and L2–L3) are useful for estimating VAT volume. Therefore, determining the optimum measurement site remains challenging and has become important in determining VAT volume. We investigated the influence of a single-slice measurement site on the prediction of VAT volume and changes in VAT volume in obese Japanese men. Methods Twenty-four men, aged 30–65 years with a mean BMI of 30 kg/m2, were included in a 12-week weight loss program. We obtained continuous T1-weighted abdominal magnetic resonance images from T9 to S1 with a 1.5-T system to measure the VAT area. These VAT areas were then summed to determine VAT volume before and after the program. Results Single-slice images at 3–11 cm above L4–L5 had significant and high correlations with VAT volume at baseline (r = 0.94–0.97). The single-slice image with the highest correlation coefficient with respect to VAT volume was located at 5 cm above L4–L5 (r = 0.97). The highest correlation coefficient between the individual changes in VAT area and changes in VAT volume was located at 6 cm above L4–L5 (r = 0.90). Conclusions Individual measurement sites have different abilities to estimate VAT volume and changes in VAT volume in obese Japanese men. Best zone located at 5–6 cm above L4–L5 may be a better predictor of VAT volume than the L4–L5 image in terms of both baseline and changes with weight loss.