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Dunnett's Test (dunnett + test)
Selected AbstractsThyroid-Stimulating Hormone Restores Bone Volume, Microarchitecture, and Strength in Aged Ovariectomized Rats*,,§JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2007T Kuber Sampath PhD Abstract We show the systemic administration of low levels of TSH increases bone volume and improves bone microarchitecture and strength in aged OVX rats. TSH's actions are mediated by its inhibitory effects on RANKL-induced osteoclast formation and bone resorption coupled with stimulatory effects on osteoblast differentiation and bone formation, suggesting TSH directly affects bone remodeling in vivo. Introduction: Thyroid-stimulating hormone (TSH) receptor haploinsufficient mice with normal circulating thyroid hormone levels have reduced bone mass, suggesting that TSH directly affects bone remodeling. We examined whether systemic TSH administration restored bone volume in aged ovariectomized (OVX) rats and influenced osteoclast formation and osteoblast differentiation in vitro. Materials and Methods: Sprague-Dawley rats were OVX at 6 months, and TSH therapy was started immediately after surgery (prevention mode; n = 80) or 7 mo later (restoration mode; n = 152). Hind limbs and lumbar spine BMD was measured at 2- or 4-wk intervals in vivo and ex vivo on termination at 8,16 wk. Long bones were subjected to ,CT, histomorphometric, and biomechanical analyses. The direct effect of TSH was examined in osteoclast and osteoblast progenitor cultures and established rat osteosarcoma-derived osteoblastic cells. Data were analyzed by ANOVA Dunnett test. Results: In the prevention mode, low doses (0.1 and 0.3 ,g) of native rat TSH prevented the progressive bone loss, and importantly, did not increase serum triiodothyroxine (T3) and thyroxine (T4) levels in aged OVX rats. In restoration mode, animals receiving 0.1 and 0.3 ,g TSH had increased BMD (10,11%), trabecular bone volume (100,130%), trabecular number (25,40%), trabecular thickness (45,60%), cortical thickness (5,16%), mineral apposition and bone formation rate (200,300%), and enhanced mechanical strength of the femur (51,60%) compared with control OVX rats. In vitro studies suggest that TSH's action is mediated by its inhibitory effects on RANKL-induced osteoclast formation, as shown in hematopoietic stem cells cultivated from TSH-treated OVX rats. TSH also stimulates osteoblast differentiation, as shown by effects on alkaline phosphatase activity, osteocalcin expression, and mineralization rate. Conclusions: These results show for the first time that systemically administered TSH prevents bone loss and restores bone mass in aged OVX rats through both antiresorptive and anabolic effects on bone remodeling. [source] Influence of endodontic sealer cement on fibreglass post bond strength to root dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2008M. S. Menezes Abstract Aim, To test the hypothesis that the composition of endodontic sealer cements and the time elapsed between root filling and fibreglass post fixation interferes with adhesion to root canal dentine. Methodology, Sixty bovine incisor roots were divided into five groups (n = 12): CI, unfilled; SI, filled with a calcium hydroxide-based cement-Sealer 26, and immediate post fixation; S7, Sealer 26 and post fixation after 7 days; EI, filled with a zinc oxide and eugenol-based cement-Endofill and immediate fixation; and E7 Endofill and post fixation after 7 days. The posts were cemented with adhesive system and dual resin cement. Ten roots were cross-sectioned to obtain two 1-mm-thick discs for each cervical (TC), middle (TM) and apical (TA) third of the prepared root portion. The posts were submitted to a micropush-out test. The other two teeth were evaluated using scanning electron microscopy to analyse the bond interface. Data were analysed using anova, Tukey and Dunnett tests (P < 0.05). Results, Group EI was associated with a significant reduction in bond strength values irrespective of the root region; TC = 3.50 MPa (P = 0.0001); TM = 2.22 MPa (P = 0.0043) and TA = 1.45 MPa (P = 0.003). Region of canal had an influence on the values for the cement used in group E7, in which only the TA presented differences from the CI. Conclusions, Endofill interfered negatively with the bond to root dentine along its full length and in the TA when post fixation was delayed for 7 days. Bond strength decreased from crown to apex in all groups. [source] Influence of progesterone on myometrial contractility in pregnant mice treated with lipopolysaccharideJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2007Hiroshi Anbe Abstract Aim:, To evaluate the effect of progesterone on interleukin (IL)-6, prostaglandin (PG) E2 and nitric oxide (NO) metabolite (NOx) production and contractile activity by NO in pregnant mice treated with lipopolysaccharide (LPS). Methods:, Pregnant C57BL mice on day 14 of gestation were killed 6 h after i.p. injection of LPS (400 ,g/kg) or vehicle. Progesterone (2 mg) was subcutaneously injected 2 h before LPS treatment. Uterine rings were equilibrated in Krebs-Henseleit solution (37°C) bubbled with 20% O2 and 5% CO2 (pH 7.4) for sampling and isometric tension recording. IL-6, PGE2 and NOx productions were measured from the bathing solution. Changes in spontaneous contractile activity in response to cumulative concentrations of l -arginine, diethylamine/nitric oxide (DEA/NO, the NO donor), and 8-bromo-cGMP (8-br-cGMP) were compared. Integral contractile activity over 10 min after each concentration was calculated and expressed as percentage change from basal activity. Statistical analyses were performed using one-way anova followed by Dunnett's test (significance was defined as P < 0.05). Results:, Interleukin-6 (34.7 ± 6.0 pg/g tissue), PGE2 (66.8 ± 6.7 pg/g tissue) and NOx (51.0 ± 5.4 pmol/2 mL/g wet tissue) production were significantly stimulated by LPS treatment (138.2 ± 23.2, 147.0 ± 29.0, 98.6 ± 16.2, respectively; P < 0.05). l -arginine, DEA/NO and 8-br-cGMP concentration-dependently inhibited spontaneous contractions in uterine rings both in LPS-treated and -untreated animals. Treatment with LPS significantly attenuated the maximal inhibition induced by l -arginine, DEA/NO and 8-br-cGMP in uterine rings from pregnant mice. Progesterone significantly decreased the levels of IL-6 production (74.9 ± 12.1, P < 0.05), but not PGE2 and NOx production, and contractile responses by l -arginine, DEA/NO and 8-br-cGMP. Conclusions:, The administration of LPS is associated with increases in IL-6, PGE2 and NO, and these increases may or may not have a role to play in LPS-induced preterm labor. Progesterone reduced the LPS-induced increase in IL-6 production and this may be one of the ways that progesterone reduces the risk of preterm labor. [source] Comparison of clozapine and haloperidol on some autonomic and psychomotor functions, and on serum prolactin concentration, in healthy subjectsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 3 2001J. L. Pretorius Aims To compare the autonomic, neuroendocrine and psychomotor effects of single doses of the ,atypical' antipsychotic clozapine and the ,classical' antipsychotic haloperidol, in healthy male volunteers. Methods Clozapine (50 mg), haloperidol (3 mg) and placebo were administered to 12 healthy male volunteers at weekly intervals, according to a balanced double-blind design. Resting pupil diameter, salivary output, heart rate, blood pressure, plasma prolactin concentration, critical flicker fusion frequency and subjective ,alertness', ,contentedness' and ,anxiety' were measured at baseline and 2, 3, 4 and 5 h after drug ingestion. Data were analysed by analysis of variance with individual comparisons (Dunnett's test) with a significance criterion of P < 0.05. Results Significant treatment effects (difference from placebo [mean, 95% CI] 5 h after drug ingestion) were as follows: clozapine reduced pupil diameter (mm; ,3.02 [,3.56, ,2.47]), salivary output (g; ,0.34 [,0.60, ,0.08]), mean arterial blood pressure (mm Hg; ,8.7 [,14.3, ,3.1]), critical flicker fusion frequency (Hz; ,3.26 [,3.94, ,2.58]), and subjectively-rated ,alertness' (mm; ,20.94 [,29.21, ,12.67]) and ,contentedness' (mm; ,12.98 [,17.90, ,8.06]), whereas haloperidol increased prolactin concentration (mU l,1; 301.3 [196.7, 405.8]) and caused small reductions in pupil diameter (mm; ,0.68 [,1.23, ,0.14]), mean arterial blood pressure (mm Hg; ,7.0 [,12.6, ,1.4]) and critical flicker fusion frequency (Hz; ,1.15 [,1.83, ,0.47]). Conclusions The effects of the antipsychotics are in agreement with their receptor binding profiles: ,1 -adrenoceptor blockade by clozapine may contribute to reductions in pupil diameter, salivation, mean arterial blood pressure and sedation, and muscarinic cholinoceptor blockade by the drug may underlie the reduction in salivation. Conversely, D2 dopamine receptor blockade by haloperidol is likely to be responsible for the increase in prolactin secretion evoked by the drug. [source] | ||||||||||