872 resultados para Neuromuscular blockers
Resumo:
We reexamined the morphological and functional properties of the hyoid, the tongue pad, and hyolingual musculature in chameleons. Dissections and histological sections indicated the presence of five distinctly individualized pairs of intrinsic tongue muscles. An analysis of the histochemical properties of the system revealed only two fiber types in the hyolingual muscles: fast glycolytic and fast oxidative glycolytic fibers. In accordance with this observation, motor-endplate staining showed that all endplates are of the en-plaque type. All muscles show relatively short fibers and large numbers of motor endplates, indicating a large potential for fine muscular control. The connective tissue sheet surrounding the entoglossal process contains elastin fibers at its periphery, allowing for elastic recoil of the hyolingual system after prey capture. The connective tissue sheets surrounding the m. accelerator and m. hyoglossus were examined under polarized light. The collagen fibers in the accelerator epimysium are configured in a crossed helical array that will facilitate limited muscle elongation. The microstructure of the tongue pad as revealed by SEM showed decreased adhesive properties, indicating a change in the prey prehension mechanics in chameleons compared to agamid or iguanid lizards. These findings provide the basis for further experimental analysis of the hyolingual system. © 2001 Wiley-Liss, Inc.
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Background: Cyclosporin A and nifedipine cause gingival overgrowth in rat, and the combined use of these drugs increases the overgrowth severity. Objective: The purpose of this study was to compare gingival overgrowth of rats of differents ages treated with cyclosporin A and nifedipine alone or given concurrently. Materials and methods: Rats 15, 30, 60 and 90 d old were treated with 10 mg/kg body weight of cyclosporin A and/or 50 mg/kg body weight of nifedipine in the chow. Results: Young rats showed evident gingival overgrowth with nifedipine, cyclosporin A, and cyclosporin A and nifedipine given concurrently. Adult rats did not show significant gingival alterations when treated with cyclosporin A and nifedipine alone. Nevertheless evident gingival overgrowth with alterations of the epithelium and connective tissue were observed when treated simultaneously with cyclosporin A and nifedipine. Conclusion: These results suggest that the combined effects of cyclosporin A and nifedipine on gingival overgrowth in rat is not age dependent.
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Background: There is some evidence showing that cyclosporin A (CsA) and nifedipine (NIF) affect bone metabolism. The purpose of this work was to study the effects of CsA and NIF, given alone or concurrently, on alveolar bone of rats of different ages. Methods: Rats 15, 30, 60, and 90 days old were treated daily with 10 mg/kg body weight of CsA subcutaneously injected and/or 50 mg/kg body weight of NIF/day given orally for 60 days. Alveolar bone of the first lower molars was morphologically and stereologically evaluated in serial 5 μm bucco-lingual paraffin sections, stained with hematoxylin and eosin. Serum calcium and alkaline phosphatase levels were measured in all animals at the end of the experimental period. Results: Rats treated with CsA or NIF alone or CsA and NIF concurrently showed decreased alveolar bone density. CsA was more effective than NIF. A significant decrease in serum calcium was found only in animals treated with CsA or CsA/NIF. The results were similar regardless of age. Conclusions: These results indicate that the decrease in the alveolar bone volume in rats caused by CsA and NIF alone or concurrently is not age dependent. Furthermore, NIF (50 mg/kg) did not further increase the loss of alveolar bone volume induced by CsA (10 mg/kg).
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A manufactured product (Ectoplus®) composed by a cypermethrin (44.7%) and dichlorvos (4.2%) mixture was administered (10mg/kg/day, orally, by gavage) to pregnant rats, during the periods of gestation+lactation, gestation, and lactation. Control mothers received vehicle aqueous solution during the gestation+lactation period. With the progeny, in the 1-15 post-natal days (PNDI-15) there were observed alterations in the periods of occurrence of teeth, hair, unfolding of ears, and in the developmental period for following reflexes: postural, palmar grasp, negative geotaxis, and acoustic startle reflex. After weaning (PND21), there were observed the presence of cypermethrin and dichlorvos in the blood brain and liver; decrease in weight of liver, of cholinesterase activity in the plasma, liver, and brain, and hepatic metabolizing activity of drugs; alterations of levels of gamma glutamyl transferase enzymes, of creatinine, and of potassium in the serum of the animals. In conclusion, neonatal exposure to a formulated mixture of cypermethrin and dichlorvos is inductive to alterations in characteristics that indicate somatic and neuromuscular development of the progeny, and in certain biochemical parameters. The results suggest that enzymatic assessment associated with somatic and neuromotor assessment can be important markers of developmental characteristics in neonatal toxicity by pesticide formulations based on mixtures of insecticides.
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The administration of calcium channel blockers has been associated with gingival overgrowth. However, there are few studies in humans or animals that evaluated the effect of diltiazem on gingival tissues. The present study assessed the influence of diltiazem, at different dosages and treatment duration, on gingival tissues of rats, using clinical, histological and histometric analyses. Eighty young male rats were separated into eight groups according to the dosage and duration of treatment. Rats were treated for 20 or 40 days with a daily subcutaneous injection of 5, 20 or 50 mg/kg of body weight of diltiazem. The results confirmed that diltiazem did not induce gingival overgrowth in rats. For all animals, the evaluation did not show gingival alterations regardless of the dosages and periods of treatment. The histometric analysis showed no significant change in the area of epithelium and connective tissues, although after 40 days of treatment a decrease in the area of connective tissue was observed, without statistically significant difference from control groups. Within the limits of this study, we suggest that diltiazem did not induce gingival overgrowth.
Comparação entre o desempenho motor de hommes e mulheres em séries múltiplas de exercícios com pesos
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The magnitude of men and women's neuromuscular, metabolic, and morphologic responses seems to be quite different even when both are submitted to exercise protocols using similar weight exercises protocols. However, differences in the motor performance between men and women have been predominantly reported in protocols based on isometric and isokinetic contractions. Thus, this study aimed to analyze men and women's behavior during multiple sets of weight exercises achieving the exhaustion, and later verifying possible differences as to the physical performance between genders using weights with similar intensity. For this, 83 subjects (50 men, and 33 women), 48 hours after being submitted to 1-RM tests in bench press, squat and arm curl performed a protocol composed by four sets at 1-RM 80% up to achieving the exhaustion in each of three exercises to evaluate the endurance ability to the fatigue in different muscular groups. It was used the ANOVA and ANCOVA for repeated measurements, followed by the Tukey's post hoc test, where P < 0.05 to the data treatment. It was verified a significant fall in the performance both in men and in women since the first up to the fourth sets of every exercise investigated (P < 0.01). Although the fatigue magnitude was higher in men in all the three exercises, the effect on the gender was only identified in the arm curl exercise (P < 0.01). The results of this study indicated that men and women presented quite different behavior in multiple sets of weight exercises, and women presented a more stable performance and a higher endurance ability to the fatigue in the arm curl as well.
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Purpose: To evaluate the characteristics of the essential blepharospasm and hemifacial spasm patients and the feasible treatment with botulinum toxin. A. Methods: Thirty-four essential blepharospasm or hemifacial spasm patients were evaluated according to gender, ocular complaint, time of disease, treatment outcome and complications. Results: Age median was 63 years and the mean was 61 years, with no difference regarding sex; 66.66% of the patients had hemifacial spasm and 33.33%, essential blepharospasm. Many patients complained of dry eye associated with involuntary spasm. Botulinum toxin A showed a positive outcome in 91.30% of the treated patients and complications observed after treatment were eyelid ptosis (8.33%) and buccal angle deviation (8.33%). Conclusion: Essential blepharospasm and hemifacial spasm occurred in the elderly, of both sexes. Treatment with botulinum toxin A was useful, with very low complication rates.
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Chronic obstructive pulmonary disease is progressive and is characterized by abnormal inflammation of the lungs in response to inhalation of noxious particles or toxic gases, especially cigarette smoke. Although this infirmity primarily affects the lungs, diverse extrapulmonary manifestations have been described. The likely mechanisms involved in the local and systemic inflammation seen in this disease include an increase in the number of inflammatory cells (resulting in abnormal production of inflammatory cytokines) and an imbalance between the formation of reactive oxygen species and antioxidant capacity (leading to oxidative stress). Weakened physical condition secondary to airflow limitation can also lead to the development of altered muscle function. Chronic obstructive pulmonary disease presents diverse systemic effects including nutritional depletion and musculoskeletal dysfunction (causing a reduction in exercise tolerance), as well as other effects related to the comorbidities generally observed in these patients. These manifestations have been correlated with survival and overall health status in chronic obstructive pulmonary disease patients. In view of these facts, the aim of this review was to discuss findings in the literature related to the systemic manifestations of chronic obstructive pulmonary disease, emphasizing the role played by systemic inflammation and evaluating various therapeutic strategies.
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A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.
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Physical exercise induces hemodynamic/ventilatory and neuromuscular adaptations that can be reverted with interruption of the training program. The aim of the present study was to evaluate the effect of detraining on physical fitness related to health. Forty-four healthy subjects, both male and female, aged 57.6±8.9 years performed the 'Mexa-se Pró-Saúde' protocol with nutritional orientation and supervised physical exercises for nine months. The program consisted of aerobic, localized muscular endurance and flexibility exercises, with duration 80 minutes/session, five days/week. Only subjects who participated in the program for more than three days/week have been selected. The detraining period was one month. Weight (kg) and height (m) were measured and the body mass index (BMI) calculated. Additionally, motors tests to evaluate the flexibility (FLEX), strength of lower limbs (SLL) and upper limbs (SUL), and maximal oxygen uptake (VO2máx) were conducted in the beginning of the study (MI), after nine months of practicing (MT) and after detraining period (MD). ANOVA (p<0.05) and Tukey test to show the difference between groups when it evidence were used for statistical treatment. The results showed that the gains of 22% and 7% on SLL and VO2máx respectively, obtained with the training, have not changed during the detraining period; however, the flexibility gain of 8% returned back to baseline after the detraining period. BMI and SUL did not change during the study. Although the lower limbs strength gains and maximal oxygen uptake obtained have been kept, one month of detraining was enough for losing the flexibility acquired.
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The purpose of this study was to evaluate anti-inflammatory drugs in the medium- and long-term management of mild to moderate carpal tunnel syndrome (CTS). The authors conducted a systematic review of the literature on the effectiveness of steroidal and nonsteroidal anti-inflammatory drugs for mild and moderate cases of CTS. There were included only randomized, double-blind clinical trials. Six publications referring to five trials were included in the review. No study on nonsteroidal anti-inflammatory drugs met our inclusion criteria. Although neurophysiological studies have not shown great differences resulting from the application of corticosteroids, the symptomatic benefit provided by such drugs is clear. In the short term, local infiltration provides better results than systemic administration of corticosteroids. Over a 1-year period, however, this difference does not persist. Further double-blind randomized trials evaluating therapeutic efficacy for a longer follow-up period are required to provide stronger evidence for both steroidal and nonsteroidal anti-inflammatories. © 2009 by Lippincott Williams & Wilkins.
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BACKGROUND AND OBJECTIVES: Myotonic dystrophies are autosomal dominant neuromuscular diseases. Among them, myotonic dystrophy type 1 (MD1), or Steinert disease, is the most common in adults, and besides muscular involvement it also has important systemic manifestations. Myotonic dystrophy type 1 poses a challenge to the anesthesiologist. Those patients are more sensitive to anesthetics and prone to cardiac and pulmonary complications. Besides, the possibility of developing malignant hyperthermia and myotonic episodes is also present. CASE REPORT: This is a 39-year old patient with DM1 who underwent general anesthesia for videolaparoscopic cholecystectomy. Total intravenous anesthesia with propofol, remifentanil, and rocuronium was the technique chosen. Intercurrences were not observed in the 90-minute surgical procedure, but after extubation, the patient developed respiratory failure and myotonia, which made tracheal intubation impossible. A laryngeal mask was used, allowing adequate oxygenation, and mechanical ventilation was maintained until full recovery of the respiratory function. The patient did not develop further complications. CONCLUSIONS: Myotonic dystrophy type 1 presents several particularities to the anesthesiologist. Detailed knowledge of its systemic involvement along with the differentiated action of anesthetic drugs in those patients will provide safer anesthetic-surgical procedure.
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Background: Cardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB) have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted.Methods/design: This is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution.Discussion: The putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil. Clinical trials registration number: ClinicalTrials.gov: NCT00971165. © 2011 Fuchs et al; licensee BioMed Central Ltd.
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Purpose. Fatigue has been pointed as a fall risk in the elderly; however, the effects of prolonged gait on neuromuscular recruitment and on its pattern remain unknown. The aim of this study was to evaluate the effects of prolonged gait on neuromuscular recruitment levels and spatial-temporal gait variables. Methods. Eight healthy older women (age: 72.63 ± 6.55 years) walked at their preferred walking speed for twenty minutes on a treadmill. The Root Mean Square (RMS) from the vastus-lateralis, femoral biceps, tibialis anterior and lateral gastrocnemius muscles were determined at the first and last minute of the test during the moments of Heel Strike (HS), Terminal Stance and Terminal Swing (TS). In addition, coactivation in the knee and ankle as well as the stride cadence and length were measured in the test. The two RMS data (taken at the first and last minute) were compared by means of a Student's t-test. Results. Twenty minutes of walking induced fatigue in the subjects, as observed through an increase in RMS, notably during the HS and TS. Coactivation was also influenced by the prolonged gait test. The only gait phase where a risk of falling was enhanced was the HS. Nonetheless, subjects developed strategies to maintain a safe motor pattern, which was evidenced by an increase in stride length and a decrease in stride cadence. Conclusion. Tests lasting just twenty minutes on a treadmill were enough to induce fatigue in older adults. However, the level of fatigue was not enough to present a danger or fall risk to elderly individuals.
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Acylpolyamines are low molecular mass toxins occurring exclusively in the venoms from solitary wasps and some groups of spiders. Their chemical structures have been elucidated using hyphenated techniques of mass spectrometry, such as LC-MS and MS/MS, or through direct analysis with different types of NMR analyses. The chemical structures of the acylpolyamine toxins from the venoms of Nephilinae orb-web spiders appear to be organized into four parts based on the combinatorial way that the chemical building blocks are bound to each other. An aromatic moiety (part I) is connected through a linker amino acid (part II) to a polyamine chain (part III), which in turn may be connected to an optional tail (part IV). The polyamine chains were classified into seven subtypes according to the different combinations of chemical building blocks. These polyamine chains, in turn, are connected to one of three chromophore moieties: a 2,4-dihydroxyphenyl acetyl group, a 4-hydroxyindolyl acetyl group, or an indolyl acetyl group. They may be connected through an asparagine residue or sometimes through the dipeptide ornithyl asparagine. Also, nine different types of backbone tails may be attached to the polyamine chains. These toxins are noncompetitive blockers of ionotropic glutamate receptors with neuroprotective action against the neuronal death and antiepileptic effect. Thus, compounds of this class of spider venom toxin seem to represent interesting molecular models for the development of novel neuropharmaceutical drugs. © 2012 Elsevier B.V. All rights reserved.