PubMed · 3083267
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J M Diamond. Ethnic differences. Variation in human testis size.. https://doi.org/10.1038/320488a0
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OBJECTIVES: One of the long-term consequences of estrogen deficiency in postmenopausal women is an increased risk of osteoporosis. Fractures of the hip and lumbar spine are associated with considerable morbidity and mortality. Estrogen replacement therapy reduces the risk of osteoporosis, but there is no clear agreement on the most appropriate doses to be used. The aim of this study was to compare changes in bone mineral density (BMD) measurements using conventional and lower dose estradiol. METHODS: A prospective, randomized, placebo-controlled 12-month study of the effect of 1 and 2 mg estradiol on BMD in 152 hysterectomized postmenopausal Chinese women with no contraindication to the use of estrogen replacement therapy. RESULTS: Over 12 months, spinal BMD in placebo treated patients decreased by a mean of 2% from baseline (-0.02+/-0.03 g/cm(2)) while it increased by 2% in the 1 mg (0.02+/-0.03 g/cm(2)) and 3% in the 2 mg group (0.03+/-0.03 g/cm(2)). Mean changes in BMD over 12 months in the hip were -0.02+/-0.02 g/cm(2) (-2%), 0.01+/-0.02 g/cm(2) (+1%) and 0.01+/-0.03 g/cm(2) (+1%) in the placebo, 1 and 2 mg estradiol groups, respectively (P<0.05). Relative to placebo, increases in BMD in both 1 and 2 mg groups were statistically significant for both spine and hip (P<0.05). However, there was no significant difference in the increase in BMD between the 1 and 2 mg doses for either lumbar spine or hip (P=0.82, 0.53, respectively). CONCLUSION: The results of our study show that a 1 mg dose of oral estradiol is effective in preventing bone loss in postmenopausal Chinese women.
Reconstituted 3-dimensional human skin equivalents containing melanocytes and keratinocytes on an artificial dermal substitute are gaining popularity for studies of skin metabolism because they exhibit morphological and growth characteristics similar to human epidermis. In this study, we show that such a pigmented epidermis model can be used to assess the regulation of pigmentation by known melanogenic compounds. In monolayers or in melanocyte-keratinocyte co-cultures, melanocyte-keratinocyte interactions are missing or are spatially limited. The commercial skin equivalents used in this study were derived from epidermal cells obtained from donors of three different ethnic origins (African- American, Asian, and Caucasian), and they reflect those distinct skin phenotypes. We used these pigmented human epidermis models to test compounds for potential effects on pigmentation in a more physiologically relevant context, which allows further characterization and validation of interesting melanogenic factors. We used known melanogenic stimulators (alpha-melanocyte-stimulating hormone and 3,4-dihydroxyphenylalanine) and inhibitors (hydroquinone, arbutin, kojic acid, and niacinamide) and examined their effects on the production of melanin and its distribution in upper layers of the skin. Our studies indicate that commercial skin equivalents provide a convenient and cost-effective alternative to animal testing for evaluating the regulation of mammalian pigmentation by melanogenic factors and for elucidating their mechanisms of action.
INTRODUCTION: Two mutations in CYP1A2, -164C-->A (allele CYP1A2*F) and -3858G-->A (allele CYP1A2*C), affecting the inducibility of the enzyme, have been published. The aim of this study was to develop a high throughput allelic discrimination assay for these mutations in both saliva and blood and to determine their frequency in Caucasians. METHODS: An allelic discrimination assay, based on the fluorogenic 5'-nuclease activity (TaqMan), was developed for the two mutations. Genomic DNA extracted from 17 saliva and 100 blood samples from Caucasians was analysed. RESULTS AND CONCLUSIONS: For the -164C-->A mutation, we found an allelic frequency of 68% in the Caucasian population, comparable with data published for Asians and Caucasians. For the -3858G-->A mutation, the allele frequency was only 2% in Caucasians, a much lower value than the approximately 25% reported in Asians (P<0.001). The presented allelic discrimination allows fast and accurate detection of these two mutations. Genotype calls were 100% identical for DNA from saliva and blood. Saliva is easily accessible and represents an excellent alternative to the traditionally used venous blood for genotyping.