196 research outputs found
The different requirement of l-T4 therapy in congenital athyreosis compared with adult-acquired hypothyroidism suggests a persisting thyroid hormone resistance at the hypothalamic-pituitary level.
No full textBackground : Levothyroxine (L-T4) is commonly employed to correct hormone deficiency in children with congenital hypothyroidism (CH) and in adult patients with iatrogenic hypothyroidism. Objective: To compare the daily weight-based dosage of the replacement therapy with L-T4 in athyreotic adult patients affected by CH and adult patients with thyroid nodular or cancer diseases treated by total thyroidectomy. Design and methods: A total of 36 adult patients (27 females and nine males) aged 18-29 years were studied; 13 patients (age: 21.5±2.1, group CH) had athyreotic CH treated with L-T4 since the first days of life. The remaining 23 patients (age: 24±2.7, group AH) had hypothyroidism after total thyroidectomy (14 patients previously affected by nodular disease and nine by thyroid carcinoma with clinical and biochemical remission). Patient weight, serum free thyroid hormones, TSH, thyroglobulin (Tg), anti-Tg, and anti-thyroperoxidase antibodies were measured. Required L-T4 dosage was evaluated. At the time of the observations, all patients presented free thyroid hormones within the normal range and TSH between 0.8 and 2 μIU/ml. Results: Patients had undetectable Tg and anti-thyroid antibodies. The daily weight-based dosage of the replacement therapy with L-T4 to reach euthyroidism in patients of group CH was significantly higher than that in those of group AH (2.16±0.36 vs 1.73±0.24 μg/kg, P=0.005). Patients of group CH treated with L-T4 had significantly higher serum TSH levels than patients of group AH (PZ0.05) as well as higher FT4 concentrations. Conclusions: To correct hypothyroidism, patients of group CH required a daily L-T4 dose/kg higher than group AH patients, despite higher levels of TSH. The different requirement of replacement therapy between adult patients with congenital and those with surgical athyroidism could be explained by a lack of thyroid hormones since fetal life in CH, which could determine a different set point of the hypothalamus-pituitary-thyroid axis
Tectonic structures and commercial compartments in active quarrying: a case history from northern Italy
No full textTectonic structures and commercial compartments in active quarrying: a case history from northern Italy
No full textBy studying a quarried site exposed in the Ligurian Alps (northern Italy), this work aims to assess the impact of the tectonic structures on the exploitable rock volume characteristics/properties and, more in general, on the three-dimensional quarry architecture for its future exploitation. A field-based, multidisciplinary dataset has been integrated within a 3D geological model performed in a Geographical Information System (GIS) environment. The spatial distribution, geometry, and internal fabric of the main tectonic structures (mainly represented by faults and fracture networks) have been recognised as responsible for a structural compartmentalisation within the study area. In situ geomechanical measurements (uniaxial strength by using a Schmidt hammer) have been compared with distribution of the tectonic structures. A simulation of the influence of the tectonic structures on the rock mechanical behaviour has been performed in GIS. We conclude that occurrence of tectonic structures determines a first order degree in geodiversity at quarried sites, influencing both intrinsic (lithology and petrography) and secondary (mechanical) properties of the excavated rock volume. Consequently, understanding and reconstructing the deformation style and intensity of the tectonic setting constitute a further geological exploration criterion for assessing strategy of rock excavation and exploitation. The identification of tectonic structures is relevant to face frequently documented problems in active quarrying, such as mass movement and slope failure, reduced rock-mass quality, or non-exploitable quarry domains
Immunohistochemical study of oxidative stress markers in the complex nurse cell-parasite in experimental trichinellosis
No full textThe Portoro Marble from Monte Castellana (La Spezia): petrographic and mineralogical characteristics and comparison with the historical Portoro of Monti Pisani
No full textVo2max Is Associated With Energy Expenditure Measures, Including Diet Induced Thermogenesis, Under Sedentary Conditions
No full textLow cardiorespiratory fitness predicts subsequent weight gain independently of physical activity. However, the physiological mechanisms underlying this relationship have not been fully explained. One hypothesis is that VO2max is related to measures of energy expenditure, in particular diet induced thermogenesis. Results from previous studies exploring these associations have been mixed. However, these studies may have been limited by methodological issues regarding the adjustment for energy expenditure (EE) by confounding factors and small sample size.
PURPOSE: To determine the association between VO2max and measures of 24-h thermogenesis under predominantly sedentary condition and in particular awake fed thermogenesis (AFT) a measure of diet induced thermogenesis.
METHODS: Two hundred twenty-nine American Indians from the southwest (132 men, 97 women) had measures of body composition by hydrodensitometry, resting metabolic rate (RMR) by the ventilated hood method, and then performed the intermittent treadmill run test for assessment of VO2max. On a separate day, they spent 24 hours in a whole-room calorimeter for assessment of 24-h EE, AFT, sleeping metabolic rate (SMR), and spontaneous physical activity (SPA) by radar system. As we have reported previously, AFT was calculated as the intercept of EE vs. SPA at zero activity minus SMR.
RESULTS: After adjustment for fat free mass, fat mass, age and sex, multiple regression analysis showed that a higher VO2max (L/min) was associated with a higher RMR (beta = 45.9 kcal/ day per L/min, standardized beta = 0.184, p = 0.010, n = 181) and 24-h EE (beta = 62.1, standardized beta = 0.125, p = 0.028, n = 229) and including additional adjustment for energy intake higher AFT (beta = 65.8, standardized beta = 0.334, p = 0.012, n = 179). Neither SMR (p = 0.64) nor SPA (p = 0.80) were associated with VO2max.
CONCLUSION: VO2max was associated with RMR, AFT and 24-h EE. In particular the association with AFT indicates a possible common mechanism regulating both processes and that the protective effect of higher VO2max on weight change reflect its association with measure of 24-h thermogenesis
Effect of thyroglobulin autoantibodies on the clearance of serum thyroglobulin in humans
No full textEffect of thyroglobulin autoantibodies on the clearance of serum thyroglobulin in humans
Francesco Latrofa, MD1, Debora Ricci, PhD1, Sara Bottai, MD1, Paolo Piaggi, PhD2,
Michele Marinò, MD1, Paolo Vitti, MD1
1Endocrinology Unit I, Department of Clinical and Experimental Medicine,
University Hospital of Pisa, Italy
2Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
To establish whether TgAb influence Tg clearance in humans, we correlated serum TgAb and Tg shortly after 131I treatment.
Samples were taken at the time of 131I treatment and at intervals of 15 days thereafter (up to 90 days) in 30 consecutive patients undergoing 131I treatment because of Graves’ hyperthyroidism. Tg was measured by an IMA (functional sensitivity 0.1 ng/mL), TgAb by an IMA (analytical sensitivity 6 IU/mL).
Tg was detectable in all patients at day 0. The concentrations of Tg rose from 33.2 (17.8-61.0) ng/mL at day 0 to 214.6 (116.9-393.4 ng/mL) at day 30 and then steadily decreased, reaching the lowest concentration at day 90 (10.9 [5.5-20.9] ng/mL). Compared to their levels at day 0 (23.6 [10.5-52.9] IU/mL), TgAb remained stable through 15 day and then gradually increased up to 116.6 (51.9-262.2) IU/mL at day 90. Patients were then split into two groups: with undetectable (<6 UI/l) (9 patients) or detectable (≥6) (21 patients) TgAb at day 0. Compared to the other cohort, patients with detectable TgAb showed significantly lower Tg concentrations at day 0 (20.3 [10.1-40.2] vs. 101.8 [36.6-279.8] ng/mL), similar at day 15, lower at day 30 (146.5 [74.3-287.8] vs. 514.8 [187.8-1407.9] ng/mL), at day 45 (87.5 [43.1-176.6] vs. 337.9 [120.1-947.0] ng/mL), at day 60 (61.6 [31.0-121.4] vs. 255.8 [79.0-823.8] ng/mL) and at day 75 (24.5 [11.9-49.2] vs. 249.5 [63.5-971.1] ng/mL) and similar at day 90. Compared to other patients, those with detectable TgAb showed a lower (182.5 [92.0-361.0] vs. 514.8 [187.8-1407.9] ng/mL) and an earlier (day 15 vs. day 30) peak of Tg. The mean of AUC of Tg concentrations was higher in patients with undetectable TgAb (36883 ± 44625 ng/mL) compared to the other group (17340 ± 16481 ng/mL) (p=0.02).
In conclusion, TgAb modify the changes in Tg concentrations observed immediately after 131I treatment, inducing lower levels and a precocious peak of Tg. These observations indicate that TgAb influence significantly Tg clearance in humans because they remove Tg from serum and support the concept that TgAb interference on Tg measurement is mainly due to an in vivo effect and not to analytical interference
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