925 resultados para ß-adrenergic stimulation
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Background: Some studies have suggested that the suppression of endogenous LH secretion does not seem to affect the majority of patients who are undergoing assisted reproduction and stimulation with recombinant FSH (r-FSH). Other studies have indicated that a group of normogonadotrophic women down-regulated and stimulated with pure FSH preparations may experience low LH concentrations that compromise the IVF parameters. The present study aimed to compare the efficacy of recombinant LH (r-LH) supplementation for controlled ovarian stimulation in r-FSH and GnRH-agonist (GnRH-a) protocol in ICSI cycles.Methods: A total of 244 patients without ovulatory dysfunction, aged < 40 years and at the first ICSI cycle were divided into two groups matched by age according to an ovarian stimulation scheme: Group I (n = 122): Down-regulation with GnRH-a + r-FSH and Group II (n = 122): Downregulation with GnRH-a + r-FSH and r-LH (beginning simultaneously).Result(s): The number of oocytes collected, the number of oocytes in metaphase II and fertilization rate were significantly lower in the Group I than in Group II (P = 0.036, P = 0.0014 and P = 0.017, respectively). In addition, the mean number of embryos produced per cycle and the mean number of frozen embryos per cycle were statistically lower (P = 0.0092 and P = 0.0008, respectively) in Group I than in Group II. Finally the cumulative implantation rate (fresh+thaw ed embryos) was significantly lower (P = 0.04) in Group I than in Group II. The other clinical and laboratory results analyzed did not show difference between groups.Conclusion: These data support r-LH supplementation in ovarian stimulation protocols with r-FSH and GnRH-a for assisted reproduction treatment.
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Background: The objective was to present a new ovarian response prediction index (ORPI), which was based on anti-Mullerian hormone (AMH) levels, antral follicle count (AFC) and age, and to verify whether it could be a reliable predictor of the ovarian stimulation response.Methods: A total of 101 patients enrolled in the ICSI programme were included. The ORPI values were calculated by multiplying the AMH level (ng/ml) by the number of antral follicles (2-9 mm), and the result was divided by the age (years) of the patient (ORPI=(AMH x AFC)/Patient age).Results: The regression analysis demonstrated significant (P<0.0001) positive correlations between the ORPI and the total number of oocytes and of MII oocytes collected. The logistic regression revealed that the ORPI values were significantly associated with the likelihood of pregnancy (odds ratio (OR): 1.86; P=0.006) and collecting greater than or equal to 4 oocytes (OR: 49.25; P<0.0001), greater than or equal to 4 MII oocytes (OR: 6.26; P<0.0001) and greater than or equal to 15 oocytes (OR: 6.10; P<0.0001). Regarding the probability of collecting greater than or equal to 4 oocytes according to the ORPI value, the ROC curve showed an area under the curve (AUC) of 0.91 and an efficacy of 88% at a cut-off of 0.2. In relation to the probability of collecting greater than or equal to 4 MII oocytes according to the ORPI value, the ROC curve had an AUC of 0.84 and an efficacy of 81% at a cut-off of 0.3. The ROC curve for the probability of collecting greater than or equal to 15 oocytes resulted in an AUC of 0.89 and an efficacy of 82% at a cut-off of 0.9. Finally, regarding the probability of pregnancy occurrence according to the ORPI value, the ROC curve showed an AUC of 0.74 and an efficacy of 62% at a cut-off of 0.3.Conclusions: The ORPI exhibited an excellent ability to predict a low ovarian response and a good ability to predict a collection of greater than or equal to 4 MII oocytes, an excessive ovarian response and the occurrence of pregnancy in infertile women. The ORPI might be used to improve the cost-benefit ratio of ovarian stimulation regimens by guiding the selection of medications and by modulating the doses and regimens according to the actual needs of the patients.
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There are few electrophysiologic studies in wild animals. The aim of this study was to determine normal data for motor nerve conduction studies and repetitive stimulation in sciatic-tibial and ulnar nerves in clinically normal captive coati. Eight adult ring-tailed coatis (Nasua nasua), two females and six males weighing 68 kg, were used. Average nerve conduction velocity was 70.81 m/sec (standard deviation [SD] = 3.98) and 56.93 m/sec (SD = 4.31) for the sciatic-tibial and ulnar nerves, respectively. Repetitive stimulation responses demonstrated minimal variations of the area of the compound muscle action potentials at low (3 Hz) and high (20 Hz) frequencies. The maximal obtained decremental area response was 8%. These normal data of conduction studies may be used in assessing abnormalities for clinical diagnosis. In addition, the obtained normal repetitive stimulation data were similar to dogs and humans and may be used for post- and presynaptic disturbances of the neuromuscular transmission in coatis.
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The aim of this study was to evaluate the effect of intravaginal electrical stimulation (IES) on pelvic floor muscle (PFM) strength in patients with mixed urinary incontinence (MUI). Between January 2001 and February 2002, 40 MUI women (mean age: 48 years) were studied. Urge incontinence was the predominant symptom; 92.5% also presented mild stress urinary incontinence (SUI). Selection criteria were clinical history and urodynamics. Pre-treatment urodynamic study showed no statistical differences between the groups. Ten percent of the women in each group had involuntary detrusor contractions. Patients were randomly distributed, in a double-blind study, into two groups. Group G 1 (n=20), effective IES, and group G2 (n=20), sham IES, with follow-up at 1 month. The following parameters were studied: (1) clinical questionnaire, (2) examiner's evaluation of perineal muscle strength, (3) objective evaluation of perineal muscle by perineometry, (4) vaginal weight test, and (5) urodynamic study. The IES protocol consisted of three 20-min sessions per week over a 7-week period using a Dualpex Uro 996 at 4 Hz. There was no statistically significant difference in the demographic data of both groups. The number of micturitions per 24 h after treatment was reduced significantly in both groups. Urge incontinence, present in all patients before treatment, was reduced to 15% in G1 and 31.5% in G2 post-treatment. The subjective evaluation of PFM strength demonstrated a significant improvement in G1. Objective evaluation of PFM force by perineometer showed a significant improvement in maximum peak contraction post-treatment in both groups. In the vaginal weight test, there was a significant increase in average number of cone retentions post-treatment in both groups. With regard to satisfaction level, after treatment, 80% of the patients in G1 and 65% of the patients in G2 were satisfied. There was no statistically significant difference between the groups. There was a significant improvement in PFM strength from both effective and sham electrostimulation, questioning the effectiveness of electrostimulation as a monotherapy in treating MUI.
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Background the aim of this study was to compare effective and sham intravaginal electrical stimulation (IES) in treating mixed urinary incontinence. Methods. Between January 2001 and February 2002, 40 women were randomly distributed, in a double-blind study, into two groups: group G1 (n = 20), effective IES, and group G2 (n = 20), sham IES, with follow up at one month. Different parameters was studied: 1. clinical questionnaire, 2. body mass index; 3. 60-min pad test; 4. urodynamic study. The protocol of IES consisted of three 20-min sessions per week over a seven-week period. The Dualpex Uro 996 used a frequency of 4 Hz. Results. There was no statistically significant difference in the demographic data of both groups. The number of micturitions per 24 h after treatment was reduced significantly in both groups. Urge incontinence was reduced to 15% in G1 and 31.5% in G2; there was no significant difference between the groups. In the analog wetness and discomfort sensation evaluations were reduced significantly in both groups. The pretreatment urodynamic study showed no statistical difference in urodynamic parameters between the groups. Ten percent of the women presented involuntary detrusor contractions. In the 60-min pad test, there was a significant reduction in both groups. In regards to satisfaction level, after treatment, 80% of G1 patients and 65% of G2 patients were satisfied. There was no statistically significant difference between the groups. Conclusion. Significant improvement was provided by effective and sham electrostimulation, questioning the effectiveness of electrostimulation as a monotherapy.
Electroacupuncture analgesia in dogs: is there a difference between uni- and bi-lateral stimulation?
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Objective To compare the analgesic effect of uni- and bi-lateral electroacupuncture (EA) in response to thermal and mechanical nociceptive stimuli and to investigate the cardiorespiratory, endocrine, and behavioral changes in dogs submitted to EA.Study design Prospective, randomized cross-over experimental study.Animals Eight adult, clinically healthy, cross-breed dogs, weighing 13 +/- 4 kg.Methods Dogs underwent electrostimulation at false acupoints (T-false); bilateral EA at acupoints, stomach 36, gall bladder 34 and spleen 6 (T-EA/bil); unilateral EA at the same points (T-EA/uni) or were untreated (T-control). All animals received acepromazine (0.05 mg kg(-1)) IV; and heart rate, pulse oximetry, indirect arterial blood pressure, respiratory rate, PECO2, rectal temperature, and plasma cortisol concentration were measured before, during, and after EA. Analgesia was tested using thoracic and abdominal cutaneous thermal and mechanical stimuli, and an interdigital thermal stimulus. Behavior was classified as calm or restless. Analysis of variance for repeated measures followed by Tukey's test was used for analysis of the data.Results There were no cardiorespiratory differences among the treatments. The cutaneous pain threshold was higher after EA, compared with false points. The latency period was shorter and analgesia was more intense in T-EA/bil than T-EA/uni, when both were compared with T-false and T-control. Six out of eight animals treated with EA were calm during treatment, and 5/8 and 4/8 of the T-false and T-control animals, respectively, were restless. Latency to interdigital thermal stimulation increased in T-EA/bil compared with the others. There was no difference in plasma cortisol concentrations among the treatments.Conclusions Bilateral EA produced a shorter latency period, a greater intensity, and longer duration of analgesia than unilateral stimulation, without stimulating a stress response.Clinical relevance Bilateral EA produces a better analgesic effect than unilateral EA.
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This in situ/ex vivo study evaluated whether saliva stimulated by chewing gum could prevent or reduce the wear and the percent change in microhardness (%SMH) of bovine and human enamel submitted to erosion followed by brushing abrasion immediately or after 1 h. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 min in 150 ml of cola drink, 4 times per day (at 8, 12, 16 and 20 h). Immediately after the immersions, no treatment was performed in 4 specimens, 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice, and the device was replaced into the mouth. After 60 min, the remaining 4 specimens were brushed. In the second phase, the procedures were repeated, but after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Changes in wear and %SMH were measured. ANOVA and Tukey's test showed statistical differences (p < 0.05) for the following comparisons. The chewing gum promoted less wear and %SMH. A decreasing %SMH and an increasing enamel wear were observed in the following conditions: erosion only, 60 min and 0 min. The human enamel presented greater %SMH and less wear compared to bovine enamel. The data suggest that the salivary stimulation after an erosive or erosive/abrasive attack can reduce the dental wear and the %SMH.
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We investigated the participation of central alpha(2)-adrenoceptors and imidazoline receptors in the inhibition of water deprivation-induced water intake in rats. The alpha(2)-adrenoceptor and imidazoline antagonist idazoxan (320 nmol), but not the alpha(2)-adrenoceptor antagonist yohimbine, abolished the antidipsogenic effect of moxonidine (alpha(2)-adrenoceptor and imidazoline agonist, 20 nmol) microinjected into the medial septal area. Yohimbine abolished the antidipsogenic effect of moxonidine intracerebroventricularly. Therefore, central moxonidine may inhibit water intake acting independently on both imidazoline receptors and alpha(2)-adrenoceptors at different forebrain sites.
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In the present experiments we investigated a possible involvement of imidazoline receptors of the paraventricular nucleus (PVN) of the hypothalamus on the presser effects of the angiotensin LI (ANG II) injected into the subfornical organ (SFO), in male Holtzman rats (250-300 g) with a cannula implanted into the third ventricle (3rdV), PVN and SFO. At first we tested the participation of alpha(2) and imidazoline agonist and antagonist compounds on the presser effect of ANG II injected into the 3rdV. Based on the results we may conclude that clonidine associated with rilmenidine was able to block the hypertensive response to ANG IT. The ANG II (20 pmol) injected into SFO induced a robust increase in blood pressure (37 +/- 2 mmHg). Isotonic saline (0.15 M) NaCl did not produce any change in blood pressure (5 +/- 2 mmHg). The injection of rilmenidine (30 mu g/kg/l mu L), an imidazoline agonist agent injected into PVN before ANG II injection into SFO, blocked the presser effect of ANG II (5 +/- 2 mmHg). Also, the injection of idazoxan (60 mu g/kg/mu L) before rilmenidine blocked the inhibitory effect of rilmenidine on blood pressure (39 +/- 4 mmHg). The injection of clonidine (20 nmol/mu L) prior to ANG II into the 3rdV produced a decreased in arterial blood pressure (37 +/- 2 mmHg) to (15 +/- 4 mmHg). The injection of yohimbine (80 nmol/mu L) prior to clonidine blocked the effect of clonidine on the effect of ANG II (27 +/- 2 mmHg). The injection of rilmenidine prior to ANG TI also induced a decrease in arterial blood pressure (10 +/- 3 mmHg). The injection of idazoxan prior to rilmenidine also blocked the inhibitory effect of rilmenidine (24 +/- 3 mmHg). In summary, the present study demonstrated that rilmenidine decreases the hypertensive effect of ANG II, with more potency than clonidine, even when injected into 3rdV or PVN. This study established that the PVN interacts with SFO by imidazoline receptors in order to control the arterial blood pressure. (C) Elsevier, Paris.
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Salivation induced by intraperitoneal (i.p.) injections of pilocarpine (cholinergic agonist) is reduced by intracerebroventricular (i.c.v.) injections of moxonidine (alpha(2) adrenergic and imidazoline receptor agonist). In the present study, we investigated the involvement of central alpha(2) adrenergic receptors in the inhibitory effect of i.c.v. moxonidine on i.p. pilocarpine-induced salivation. Male Holtzman rats with stainless steel cannula implanted into the lateral ventricle (LV) were used. Saliva was collected using pre-weighted small cotton balls inserted into the animal's mouth under ketamine (100 mg kg(-1)) anesthesia. Salivation was induced by i.p. injection of pilocarpine (4 mu mol kg(-1)). Pilocarpine-induced salivation was reduced by i.c.v. injection of moxonidine (10 nmol) and enhanced by i.c.v. injections of either RX 821002 (160 nmol) or yohimbine (320 nmol). The inhibitory effect of i.c.v. moxonidine on pilocarpine-induced salivation was abolished by prior i.c.v. injections of the alpha(2) adrenergic receptor antagonists, RX 821002 (160 nmol) or yohimbine (160 and 320 nmol). The alpha(1) adrenergic receptor antagonist prazosin (320 nmol) injected i.c.v. did not change the effect of moxonidine on pilocarpine-induced salivation. The results suggest that moxonidine acts on central alpha(2) adrenergic receptors to inhibit pilocarpine-induced salivation, and that this salivation is tonically inhibited by central alpha(2) adrenergic receptors. (C) 2002 Elsevier B.V. All rights reserved.
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Water and NaCl intake is strongly inhibited by the activation of alpha(2)-adrenergic receptors with clonidine or moxonidine (alpha(2)-adrenergic/imidazoline agonists) injected peripherally or into the forebrain and by serotonin and cholecystokinin in the lateral parabrachial nucleus (LPBN). Considering that alpha(2)-adrenergic receptors exist in the LPBN and the similar origin of serotonergic and adrenergic afferent pathways to the LPBN, in this study we investigated the effects of bilateral injections of moxonidine alone or combined with RX 821002 (alpha(2)- adrenergic antagonist) into the LPBN on 1.8% NaCl and water intake induced by the treatment with s.c. furosemide (10 mg/kg)+captopril (5 mg/kg). Additionally, we investigated if moxonidine into the LPBN would modify furosemide+captopril-induced c-fos expression in the forebrain. Male Holtzman rats with cannulas implanted bilaterally in the LPBN were used. Contrary to forebrain injections, bilateral LPBN injections of moxonidine (0.1, 0.5 and 1 nmol/0.2 mul) strongly increased furosemide+captopril-induced 1.8% NaCl intake (16.6 +/- 2.7, 44.5 +/- 3.2 and 44.5 +/- 4.3 ml/2 h, respectively, vs. vehicle: 6.9 +/- 1.5 ml/2 h). Only the high dose of moxonidine increased water intake (23.3 +/- 3.8 ml/2 h, vs. vehicle: 12.1 +/- 2.6 ml/2 h). Prior injections of RX 821002 (10 and 20 nmol/0.2 mu1) abolished the effect of moxonidine (0.5 nmol) on 1.8% NaCl intake. Moxonidine into the LPBN did not modify furosemide+captopril-induced c-fos expression in forebrain areas related to the control of fluid-electrolyte balance. The results show that the activation of LPBN a2-adrenergic receptors enhances furosemide+captopril-induced 1.8% NaCl and water intake. This enhancement was not related to prior alteration in the activity of forebrain areas as suggested by c-fos expression. Previous and present results indicate opposite roles for alpha(2-)adrenergic receptors in the control of sodium and water intake according to their distribution in the rat brain. (C) 2004 IBRO. Published by Elsevier Ltd. All rights reserved.
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The inhibition of sodium intake by increased plasma osmolarity may depend on inhibitory mechanisms present in the lateral parabrachial nucleus. Activation of alpha(2)-adrenergic receptors in the lateral parabrachial nucleus is suggested to deactivate inhibitory mechanisms present in this area increasing fluid depletion-induced 0.3 M NaCl intake. Considering the possibility that lateral parabrachial nucleus inhibitory mechanisms are activated and restrain sodium intake in animals with increased plasma osmolarity, in the present study we investigated the effects on water and 0.3 M NaCl intake produced by the activation of alpha(2)-adrenergic receptors in the lateral parabrachial nucleus in rats with increased plasma osmolarity. Male Holtzman rats with stainless steel cannulas implanted bilaterally into the lateral parabrachial nucleus were used. One hour after intragastric 2 M NaCl load (2 ml), bilateral injections of moxonidine (alpha(2)-adrenergic/imidazoline receptor agonist, 0.5 nmol/0.2 mu l, n=10) into the lateral parabrachial nucleus induced a strong ingestion of 0.3 M NaCl intake (19.1 +/- 5.5 ml/2 h vs. vehicle: 1.8 +/- 0.6 ml/2 h), without changing water intake (15.8 +/- 3.0 ml/2 h vs. vehicle: 9.3 +/- 2.0 ml/2 h). However, moxonidine into the lateral parabrachial nucleus in satiated rats not treated with 2 M NaCl produced no change on 0.3 M NaCl intake. The pre-treatment with RX 821002 (alpha(2)-adrenergic receptor antagonist, 20 nmol/0.2 mu l) into the lateral parabrachial nucleus almost abolished the effects of moxonidine on 0.3 M NaCl intake (4.7 +/- 3.4 ml/2 h). The present results suggest that alpha(2)-adrenergic receptor activation in the lateral parabrachial nucleus blocks inhibitory mechanisms, thereby allowing ingestion of hypertonic NaCl under conditions of extracellular hyperosmolarity. We suggest that during cell dehydration, circuits subserving sodium appetite are activated, but at the same time strongly inhibited through the lateral parabrachial nucleus. (c) 2006 IBRO. Published by Elsevier Ltd. All rights reserved.
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We have studied the effects of L-NG-nitro arginine methyl esther (L-NAME), L-arginine (LAR), inhibitor and a donating nitric oxide agent on the alterations of salivary flow, water intake, arterial blood pressure (MAP) and heart rate (HR) induced by the injection pilocarpine into the subfornical organ (SFO). Rats (Holtzman 250-300 g) were anesthetized with 2, 2, 2-tribromoethanol (20 mg/100 kg b. wt.) and a stainless steel carmula were implanted into their SFO. The volume of injection was 0.2 mu l. The amount of saliva secretion was studied over a 5-min period. Pilocarpine (40 mu g), L-NAME (40 mu g) and LAR (30 mu g) were used in all experiments for the injection into the SFO. Pilocarpine (10, 20, 40, 80 and 160 mu g) injected into SFO elicited a concentration-dependent increase in salivary secretion. L-NAME injected prior to pilocarpine into the SFO increased salivary secretion and water intake due to the effect of pilocarpine. LAR injected prior to pilocarpine into the SFO attenuated the salivary secretion and water intake. Pilocarpine, injected into the SFO increased the MAP and decreased heart rate (HR). L-NAME injected prior to pilocarpine into the SFO potentiated the pressor effect of pilocarpine with a decrease in HR. LAR injected into the SFO prior to pilocarpine attenuated the increase in MAP with no changes in HR. The present study suggests that the SFO nitrergic cells interfere in the cholinergic pathways implicated in the control of salivary secretion, fluid and cardiovascular homeostasis. (c) 2007 Elsevier B.V All rights reserved.