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Amniotic fluid insulin and C peptide levels in diabetic and non diabetic women during early pregnancy
No full textThanks to the widespread use of amniocentesis, glucose, insulin, and C peptide have often been measured in amniotic fluid (AF) during late gestation, but little is known about their concentrations during early pregnancy. To better understand early fetal β-cell function under normal conditions and in the presence of maternal diabetes, we measured glucose, insulin, and C peptide in the AF collected during weeks 15-22 in 77 healthy and 9 diabetic women undergoing amniocentesis for clinical indications and compared the results with those obtained during late pregnancy (weeks 34- 36). The AF C peptide concentration was higher in diabetic women (102 ± 53 vs. 38 ± 2 pmol/L), in the women with a family history of diabetes (41 ± 6 vs. 35 ± 2 pmol/L), after the 19th week of gestation (46 ± 5 vs. 35 ± 2 pmol/L; in the presence of lower glucose concentrations), and in the presence of maternal plasma glucose levels greater than 5.56 mmol/L (42 ± 3.5 vs. 34 ± 2 pmol/L). The comparison between early and late gestation showed decreasing glucose and increasing C peptide concentrations in both healthy and diabetic women (in the latter, C peptide values were always 3 times higher), whereas the insulin concentration was increased in late gestation only in diabetic women. The AF C peptide/insulin molar ratio increased throughout pregnancy in both healthy (from 0.97 ± 0.06 to 4.3 ± 1.2) and diabetic (from 2.9 ± 1.1 to 13.2 ± 1.6) women. These parallel changes suggest that the fetal clearance and/or degradation of insulin and C peptide may greatly change during both normal and diabetic gestation
Impaired alpha cell function in conditions with cortisol deficiency
No full textPlasma immunoreactive glucagon (IRG), insulin (IRI) and blood glucose (BG) were evaluated in the fasting state and during an arginine test (ATT) in 6 subjects with untreated hypopituitarism (H), in 2 hypopituitary subjects with normal cortisol production (H + C), in 3 subjects with Addison's disease (A) and in 14 normal volunteers (N). No increase in BG was observed in H and A after arginine, mean values being significantly lower than in N. Mean fasting and arginine-stimulated IRI levels were lower in H and A than in N; postabsorptive arginine-induced IRG levels were significantly reduced when compared to N. In contrast IRG levels in the two H + C patients were within the normal range. The impaired IRG production in A and in H (but not in H + C) suggests a close relationship between alpha pancreatic function and cortisol levels
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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