Risperidone has a relatively low risk of causing obesity and diabetes mellitus and is a first-line treatment for schizophrenia. The aim of the present study was to investigate glucose and lipid metabolism, and feeding-control parameters in schizophrenia patients treated with long-term risperidone monotherapy. Fifteen patients with paranoid-type schizophrenia who had been treated with risperidone and had Global Assessment of Function (GAF) scores >70 were selected and compared with healthy volunteers (n = 25). Single assessments of psychotic symptoms, side-effects, Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) score, bodyweight, body fat percentage and blood sampling were performed. Fasting blood glucose, insulin, hemoglobin A1c, homeostasis model assessment insulin resistance index (HOMA-IR), total cholesterol, triglyceride, high density lipoprotein (HDL)-, low density lipoprotein-cholesterol, adiponectin, prolactin and feeding-control parameters (ghrelin and leptin) were analyzed. The body fat percentage (P = 0.0018), body mass index (BMI) (P = 0.0150), fasting blood glucose (P = 0.0358), triglyceride (P = 0.0377), leptin (P = 0.0243), total ghrelin (P = 0.0067), active ghrelin (P = 0.0241) and prolactin (P < 0.0001) levels of patients treated with risperidone were significantly higher than those of healthy volunteers, while the HDL-cholesterol level (P = 0.0222) was significantly lower. Although the patients had very mild psychiatric symptoms and maintained functionally high levels, the glucose and lipid parameters were significantly impaired compared to healthy volunteers. A high level of plasma ghrelin might increase appetite, leading to exacerbation of metabolic impairment.
The DAX-1 [DSS (dosage-sensitive sex)-AHC critical region in the X, gene 1] gene has been reported to be responsible for X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism. However, the function and structure of the DAX-1 protein have not been characterized. In this study, molecular analysis of the DAX-1 gene from 6 patients with AHC, including 2 siblings, identified 5 novel mutations with 3 nonsense mutations and 2 frameshift mutations. Case 1 had a nonsense mutation at position 395 (Q395X). Cases 2 and 3, who were siblings, had a nonsense mutation at position 91 (Y91X). Case 4 had a 2-base deletion (AT) at nucleotides 1610 and 1611 and a 1-base insertion (G) resulting in a premature stop codon at position 462 (1610-1611 del AT ins G). Case 5 had a nonsense mutation at position 271 (Y271X). Case 6 had a 1-base deletion (C) at nucleotide 1169, which induced a frame shift and a premature stop codon at position 371 (1169 del C). All mutated DAX-1 proteins had truncated C-terminal domains. In addition, reverse transcription-PCR and direct sequencing characterized the mutant messenger ribonucleic acid in testis from case 1. Our results suggest that these 5 novel mutations are responsible for X-linked AHC and that the C-terminus of the DAX-1 protein, especially the terminal 11 amino acids, is necessary for normal adrenal cortical embryogenesis.
Insulin-like growth factor-I (IGF-I) is essential for normal epidermal homeostasis; however, the role of IGF binding proteins (IGFBPs), regulators of IGF action, remains unclear. Here we examine the regulation of human keratinocyte-produced IGFBPs by epidermal growth factor (EGF), transforming growth factor beta 1 (TGFbeta1), and IGF-I, growth factors known to be active in skin. In the absence of added growth factors, IGFBP-3 was the major binding protein secreted into the medium by primary keratinocytes. Addition of EGF or TGFbeta1 to keratinocyte cultures resulted in a significant decrease in IGFBP-3 abundance in conditioned medium when compared with control, untreated cells. Specifically, EGF (50 ng/ml) and TGFbeta1 (50 ng/ml) reduced IGFBP-3 abundance to 15+/-6% and 22+/-9%, respectively. Using Northern blot analysis, we found EGF and TGFbeta1 (50 ng/ml) to reduce IGFBP-3 mRNA levels in keratinocytes to 51+/-12% and 50+/-38%, respectively, when compared with control, untreated cells. Treatment with IGF-I or its analogue des(1-3)IGF-I did not lead to any consistent change in IGFBP-3 abundance. However, both IGF-I and des(1-3)IGF-I at 100 ng/ml led to a modest increase in IGFBP-3 mRNA levels in keratinocytes, suggesting posttranscriptional regulation of IGFBP-3 abundance. We propose that local modulation of IGFBP-3 abundance may represent another level of regulation of growth factor action in the epidermis, where EGF and TGFbeta1 and possibly other local growth factors specifically regulate the availability of IGF-I to its keratinocyte receptors.
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