scholarly journals Dihydrotestosterone, stanozolol, androstenedione and dehydroepiandrosterone sulphate inhibit leptin secretion in female but not in male samples of omental adipose tissue in vitro: lack of effect of testosterone

1999 ◽  
Vol 160 (3) ◽  
pp. 425-432 ◽  
Author(s):  
V Pineiro ◽  
X Casabiell ◽  
R Peino ◽  
M Lage ◽  
JP Camina ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
In Vitro Study ◽  
Significant Inhibition ◽  
Dehydroepiandrosterone Sulphate ◽  
Organ Cultures ◽  
Omental Adipose Tissue ◽  
The Central Nervous System ◽  
The Mean ◽  
Gender Based

Leptin, the product of the Ob gene, is a polypeptide hormone expressed in adipocytes which acts as a signalling factor from the adipose tissue to the central nervous system, regulating food intake and energy expenditure. It has been reported that circulating leptin levels are higher in women than in men, even after correction for body fat. This gender-based difference may be conditioned by differences in the levels of androgenic hormones. To explore this possibility, a systematic in vitro study with organ cultures from human omental adipose tissue, either stimulated or not with androgens (1 microM), was undertaken in samples obtained from surgery on 44 non-obese donors (21 women and 23 men). The assay was standardized in periods of 24 h, ending at 96 h, with no apparent tissue damage. Leptin results are expressed as the mean+/-s.e.m. of the integrated secretion into the medium, expressed as ng leptin/g tissue per 48 h. Spontaneous leptin secretion in samples from female donors (4149+/-301) was significantly higher (P<0.01) than that from male donors (2456+/-428). Testosterone did not exert any significant effect on in vitro leptin secretion in either gender (4856+/-366 in women, 3322+/-505 in men). Coincubation of adipose tissue with dihydrotestosterone (DHT) induced a significant (P<0.05) leptin decrease in samples taken from women (3119+/-322) but not in those taken from men (2042+/-430). Stanozolol, a non-aromatizable androgen, decreased (P<0.05) leptin secretion in female samples (2809+/-383) but not in male (1553+/-671). Dehydroepiandrosterone sulphate (DHEA-S) induced a significant (P<0.01) leptin decrease in female samples (2996+/-473), with no modifications in samples derived from males (1596+/-528). Exposure to androstenedione also resulted in a significant reduction (P<0.01) of leptin secretion in samples taken from women (2231+/-264), with no effect on male adipose tissue (1605+/-544). In conclusion, DHT, stanozolol, DHEA-S and androstenedione induced a significant inhibition of in vitro leptin secretion in samples from female donors, without affecting the secretion in samples from men. Testosterone was devoid of activity in either gender.

scholarly journals TSH stimulates leptin secretion by a direct effect on adipocytes

2003 ◽  
Vol 176 (1) ◽  
pp. 7-12 ◽  
Author(s):  
C Menendez ◽  
R Baldelli ◽  
JP Camina ◽  
B Escudero ◽  
R Peino ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Homeostasis ◽  
Direct Action ◽  
Human Adipose Tissue ◽  
Pituitary Hormones ◽  
Organ Cultures ◽  
Omental Adipose Tissue ◽  
Thyroid Axis ◽  
The Central Nervous System

Leptin is a circulating hormone secreted by adipose tIssue which acts as a signal to the central nervous system where it regulates energy homeostasis and neuroendocrine processes. Although leptin modulates the secretion of several pituitary hormones, no information is available regarding a direct action of pituitary products on leptin release. However, it has been pointed out that leptin and TSH have a coordinated pulsatility in plasma. In order to test a direct action of TSH on in vitro leptin secretion, a systematic study of organ cultures of human omental adipose tIssue was performed in samples obtained at surgery from 34 patients of both sexes during elective abdominal surgery. TSH powerfully stimulated leptin secretion by human adipose tIssue in vitro. In contrast, prolactin, ACTH, FSH and LH were devoid of action. These results suggest that leptin and the thyroid axis maintain a complex and dual relationship and open the possibility that plasmatic changes in TSH may contribute to the regulation of leptin pulses.

scholarly journals Retinoic acid and vitamin D(3) powerfully inhibit in vitro leptin secretion by human adipose tissue

2001 ◽  
Vol 170 (2) ◽  
pp. 425-431 ◽  
Author(s):  
C Menendez ◽  
M Lage ◽  
R Peino ◽  
R Baldelli ◽  
P Concheiro ◽  
...  
Keyword(s):  
Vitamin D ◽  
Adipose Tissue ◽  
Retinoic Acid ◽  
Energy Homeostasis ◽  
Human Adipose Tissue ◽  
Tissue Samples ◽  
Omental Adipose Tissue ◽  
Vitamin D 3 ◽  
Gender Based

Leptin, the product of the ob gene, is secreted into the circulation by white adipose tissue; its major role being to participate in the regulation of energy homeostasis. Plasma leptin levels are mainly determined by the relative adiposity of the subject; however, the great dispersion of values for any given body mass index and the noteworthy gender-based differences indicate that other factors are operating. Steroid hormones actively participate in the regulation of leptin secretion; however, non-steroid nuclear hormones have either not been studied or have provided contradictory results. In order to understand the role of hormones of the non-steroid superfamily such as 3,5,3'-tri-iodothyronine (T(3)), vitamin D(3) and retinoic acid (RA) in the control of leptin secretion, in the present work doses of 10(-9), 10(-8) and 10(-7) M of these compounds have been studied on in vitro leptin secretion. The organ culture was performed with omental adipose tissue samples from healthy donors (n=28). T(3) was devoid of effect at any dose studied, while an inhibition of leptin secretion was observed with 9-cis-RA (slight) and all-trans-RA (potent). Interestingly, vitamin D(3) exerted a powerfully inhibitory role at the doses studied, and its action was synergistic with all-trans-RA. In conclusion, in vitro leptin secretion by human adipose tissue is negatively controlled by either RA or vitamin D(3). The clinical significance of leptin regulation by this superfamily of nuclear receptors remains to be ascertained.

scholarly journals Shear bond strength evaluation of bonded molar tubes on fluorotic molars

2012 ◽  
Vol 83 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Erika L. Silva-Benítez ◽  
Veronica Zavala-Alonso ◽  
Gabriel A. Martinez-Castanon ◽  
Juan P. Loyola-Rodriguez ◽  
Nuria Patiño-Marin ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dental Fluorosis ◽  
In Vitro Study ◽  
Mean Value ◽  
Fixed Appliance ◽  
Adhesive Remnant Index ◽  
The Mean ◽  
Electronic Microscope

Abstract Objective: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. Materials and Methods: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. Results: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. Conclusions: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.

scholarly journals Release of Inflammatory Mediators by Human Adipose Tissue Is Enhanced in Obesity and Primarily by the Nonfat Cells: A Review

2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
John N. Fain
Keyword(s):  
Adipose Tissue ◽  
In Vitro Release ◽  
Human Adipose Tissue ◽  
Fat Cells ◽  
Omental Adipose Tissue ◽  
Subcutaneous Adipose ◽  
Circulating Levels ◽  
Pai 1

This paper considers the role of putative adipokines that might be involved in the enhanced inflammatory response of human adipose tissue seen in obesity. Inflammatory adipokines [IL-6, IL-10, ACE, TGFβ1, TNFα, IL-1β, PAI-1, and IL-8] plus one anti-inflammatory [IL-10] adipokine were identified whose circulating levels as well as in vitro release by fat are enhanced in obesity and are primarily released by the nonfat cells of human adipose tissue. In contrast, the circulating levels of leptin and FABP-4 are also enhanced in obesity and they are primarily released by fat cells of human adipose tissue. The relative expression of adipokines and other proteins in human omental as compared to subcutaneous adipose tissue as well as their expression in the nonfat as compared to the fat cells of human omental adipose tissue is also reviewed. The conclusion is that the release of many inflammatory adipokines by adipose tissue is enhanced in obese humans.

scholarly journals An in vitro comparison of the force decay generated by different commercially available elastomeric chains and NiTi closed coil springs

2007 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Ana Cristina Soares Santos ◽  
André Tortamano ◽  
Sandra Regina Frazatto Naccarato ◽  
Gladys Cristina Dominguez-Rodriguez ◽  
Julio Wilson Vigorito
Keyword(s):  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Original Length ◽  
Force Decay ◽  
Decay Pattern ◽  
The Mean ◽  
Initial Force ◽  
Elastomeric Chains

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.

scholarly journals The in vitro secretion of human leptin is gender-dependent but independent of the body mass index of the donors

2000 ◽  
pp. 711-714 ◽  
Author(s):  
C Menendez ◽  
R Baldelli ◽  
M Lage ◽  
X Casabiell ◽  
V Pinero ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Adipose Tissue ◽  
Body Mass ◽  
Tissue Sample ◽  
Secretory Activity ◽  
The Body ◽  
Secretory Rate ◽  
Omental Adipose Tissue

OBJECTIVE: Leptin is an adipocyte-secreted hormone acting as a signal to the central nervous system, where it regulates energy homeostasis and neuroendocrine processes. Leptin plasma levels are mainly regulated by the percentage of body fat, but are also controlled by several metabolic and nutritional variables. Data regarding leptin secretion suggest that it is gender regulated, and higher levels are present in women than men; however, the biological basis for this sex-related difference is unknown. To clarify those points, a systematic study with tissue cultures from human omental adipose tissue was performed. DESIGN AND METHODS: Surgically obtained samples from 137 patients (68 women, 69 men) were evaluated. The assay was standardized in periods of 24 h ending at 96 h. Each adipose tissue sample from a single donor was incubated in triplicate and leptin results expressed as the mean of the integrated secretion into the medium (nanograms of leptin/g tissue per time). RESULTS: Tissue adipose cultures showed a steady leptin secretion throughout the 96 h studied, with the peak of secretory activity reached at 48 h; afterwards, the in vitro secretion reached a plateau state. Spontaneous leptin secretion in the 24 h and 48 h period, as well as the area under the curve analyzed in the 0-48 h period, showed a gender-based difference that was significantly (P<0. 05) higher in women than in men. When data of spontaneous leptin secretion were correlated with the body mass index (BMI) of the donors, no correlation was found. This suggests that in vivo leptin levels are dependent on the total amount of fat of the individual, but independent of the leptin secretory rate by the adipose tissue of the donor. CONCLUSIONS: Leptin secretion from omental adipose tissue in vitro is: (i) significantly higher in samples from women than in samples from men; and (ii) not correlated with the BMI, showing that in vitro leptin secretion is not related to the adiposity of the donor.

scholarly journals Evaluation of Gaps or Voids Occurring in Roots Filled with Three Different Sealers

2010 ◽  
Vol 04 (02) ◽  
pp. 101-109 ◽  
Author(s):  
Melek Akman ◽  
Serhan Akman ◽  
Oznur Derinbay ◽  
Sema Belli
Keyword(s):  
In Vitro Study ◽  
Gutta Percha ◽  
Rotary Instruments ◽  
Single Cone ◽  
Ah Plus ◽  
Root Dentin ◽  
The Mean ◽  
Free Interfaces ◽  
Niti Rotary Instruments

Objectives: The purpose of this in vitro study was to evaluate gaps or voids occurring in roots filled with three different sealers.Methods: Thirty extracted human single-rooted teeth were decoronated, instrumented using NiTi rotary instruments, divided into three groups (n=10 per group) and obturated with one of the following: Epiphany with Resilon, MetaSEAL with gutta-percha or AH Plus with gutta-percha using the match-taper single-cone technique. After storage for one week in 100% humidity at 37°C, the teeth were horizontally sectioned (n=10). Photographs were taken from the coronal, median and apical parts of the roots using a stereomicroscope at 10X magnification, and the images were then transferred to a computer. The mathematical method known as the ‘Affine Transformation’ was used for the transformation of pixel coordinates to ground coordinates in the Netcad Software program. The mean areas (μm2) of the gaps between the sealer and root dentin or gutta percha/resilon and the gaps between the sealer and/or voids inside the sealer mass were measured, scored on a 0-3 scale and statistically analyzed with the Kruskal-Wallis test.Results: The mean total area of gaps or voids for each sealer was 4631.80 μm2 for the Epiphany- Resilon, 3826.80 μm2 for the MetaSEAL-gutta-percha and 31334 μm2 for the AH Plus-gutta-percha. The MetaSEAL-gutta-percha group showed more gap or void-free interfaces. No significant differences were found among the sealers in the scores for the gap areas (P<.05), and the MetaSEAL showed similar interfaces with Epiphany.Conclusions: No significant differences in the mean areas of gaps or voids were found among the tested resin-based sealers. (Eur J Dent 2010;4:101-109)

scholarly journals Inhibition of Demineralization at Restoration Margins of Z100 and Tetric EvoCeram Bulk Fill in Dentin and Enamel

2019 ◽  
Vol 6 (2) ◽  
pp. 36
Author(s):  
Cristina Leon-Pineda ◽  
Kevin Donly
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
In Vitro Study ◽  
The Other ◽  
Solution Ph ◽  
Class V ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

Recurrent caries is still considered the main reason restorations need to be replaced. There are different materials available now that promise to reduce the possibility of recurrent caries by releasing fluoride and inhibiting restoration marginal caries. The purpose of this in vitro study was to evaluate the demineralization inhibition potential of a non-fluoride-releasing resin (Z100TM 3M, St. Paul, MN, USA) and a glass containing resin-based composite (Tetric EvoCeram Bulk Fill, Ivoclar/Vivadent AG, Schaan, Liechtenstein), which contains fluoride. Class V preparations were placed on 22 premolars; the gingival margin was below the cementoenamel junction and the occlusal margin was placed above the cemento-enamel junction. Ten teeth were randomly selected to be restored with Z100 while the other 10 were restored with Tetric EvoCeram Bulk Fill. Both groups were restored following manufacturer’s instructions. All teeth had an acid resistant varnish placed within one millimeter of the preparation margins. Both groups were placed in artificial caries challenge solution (pH 4.4). At the end of the 4 days; 100 µm buccolingual sections were obtained for each tooth; these were photographed under polarized light microscopy and the demineralized areas adjacent to the restorations were measured and quantified. The mean (±S.D.) area (µm2) of demineralization from the occlusal margin (enamel) and dentin margin were: Z100 2781.889 ± 1045.213; 3960.455 ± 705.964 and for Tetric EvoCeram Bulk Fill 1541.545 ± 1167.027; 3027.600 ± 512.078. Student’s t-test indicated that there was significantly less enamel and dentin demineralization adjacent to Tetric EvoCeram Bulk Fill compared to Z100; there was significantly less demineralization in enamel compared to dentin in both Tetric EvoCeral Bulk Fill and Z100. Tetric EvoCeram Bulk Fill performed better inhibiting demineralization at restoration margins when compared to Z100 and provided better demineralization inhibition in enamel than cementum/dentin.

scholarly journals Activation of antilipolytic α2-adrenergic receptors by epinephrine during exercise in human adipose tissue

1999 ◽  
Vol 277 (4) ◽  
pp. R1076-R1083 ◽  
Author(s):  
Vladimir Stich ◽  
Isabelle de Glisezinski ◽  
Francois Crampes ◽  
Hana Suljkovicova ◽  
Jean Galitzky ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
In Vitro Study ◽  
Exercise Bout ◽  
Human Adipose Tissue ◽  
Ringer Solution ◽  
Plasma Norepinephrine ◽  
Glycerol Concentration ◽  
Isolated Adipocytes ◽  
Exercise Induced

The involvement of the antilipolytic α2-adrenergic pathway and the specific role of epinephrine in the control of lipolysis during exercise in adipose tissue (AT) were investigated in healthy male subjects (age: 24.1 ± 2.2 yr; body mass index: 23.0 ± 1.6). An in vitro study carried out on isolated adipocytes showed that the weak lipolytic effect of epinephrine was potentiated after blockade of α2-adrenergic receptor (AR) by an α2-AR antagonist and reached that of isoproterenol, a β-AR agonist. The effect of the nonselective α2-AR antagonist phentolamine on the response of the extracellular glycerol concentration (EGC) in AT during two successive bouts of aerobic exercise (50% maximum O2 uptake, 60 min duration) was evaluated using the microdialysis method. The metabolic responses measured in perfused probes with Ringer solution were compared with those obtained in perfused probes with Ringer plus 0.1 mmol/l phentolamine. Plasma norepinephrine level was not different during the two exercise bouts, whereas that of epinephrine was 2.5-fold higher during the second exercise. EGC in AT was twofold higher in the second compared with the first exercise, and the same response pattern was found for plasma glycerol. The exercise-induced increase in EGC was higher in the probe perfused with phentolamine compared with the control probe in both bouts of exercise. However, the potentiating effect of phentolamine on EGC was significant during the second exercise bout but did not reach a significant level during the first. These results suggest that epinephrine is involved in the control of lipid mobilization through activation of antilipolytic α2-AR in human subcutaneous AT during exercise.

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