Effects of bromocriptine and haloperidol on prepulse inhibition: comparison of the acoustic startle eyeblink response and the N1/P2 auditory-evoked response in man

Experiments with animals have shown that D2 dopamine receptors are involved in regulating prepulse inhibition (PPI) of the acoustic startle reflex (suppression of the reflex response evoked by a loud sound by prior presentation of a low-intensity stimulus). Recently we found that PPI of the human eyeblink startle response could be suppressed by a D2 receptor agonist, bromocriptine, and that this suppression could be reversed by a D2 receptor-blocking neuroleptic, haloperidol. The present work attempted to replicate this finding and to extend it to PPI of the N1/P2 component of the auditory-evoked potential. Eleven healthy males (18-30 years) participated in four sessions in which they received oral doses of placebo, bromocriptine 1.25 mg, haloperidol 3mg and combined treatment with bromocriptine 1.25 mg + haloperidol 3 mg, according to a balanced double-blind protocol. Thirty-minute simultaneous recordings of the electromyographic (EMG) responses of the orbicularis oculi muscle of the right eye and the vertex auditory-evoked potentials took place 120 min after ingestion of haloperidol and/or 90 min after ingestion of bromocriptine. Sound stimuli (1-kHz) were presented in 60 trials separated by variable intervals (mean 25 sec): (i) 40 msec 115 dB ('pulse alone': 20 trials); (ii) 40 msec 85 dB (20 trials); (iii) 40 msec 85 dB, followed after 120 msec by 40 msec 115 dB ('prepulse/ pulse': 20 trials). The amplitudes of the EMG and N1/P2 responses were not altered significantly by any of the treatments. Bromocriptine attenuated PPI of the EMG response significantly, this attenuation being absent following combined haloperidol/bromocriptine treatment. Neither bromocriptine nor haloperidol significantly altered PPI of the N1/P2 complex. Bromocriptine suppressed and haloperidol elevated serum prolactin levels, these changes being absent when the two drugs were given in combination. The results suggest that different mechanisms may be involved in regulating PPI of the eyeblink and the N1/P2 component of the auditory-evoked potential, and that D2 receptors may be involved in the former case, but not the latter.     

Preliminary UK experience of dexmedetomidine, a novel agent for postoperative sedation in the intensive care unit

Dexmedetomidine, a highly selective and potent alpha2-adrenergic agonist, has a potentially useful role as a sedative agent in patients requiring intensive care. As part of a larger European multicentre trial, a total of 119 postoperative cardiac and general surgical patients requiring ventilation and sedation in an intensive care unit were enrolled in four centres in the United Kingdom. One hundred and five patients were randomly allocated to receive either dexmedetomidine or placebo with rescue sedation and analgesia provided by midazolam and morphine, respectively. Compared with the control group, intubated patients receiving dexmedetomidine required 80% less midazolam [mean 4.9 (5.8) microg.kg-1.h-1 vs. 23.7 (27.5) microg.kg-1.h-1, p < 0.0001], and 50% less morphine [11.2 (13.4) microg.kg-1.h-1 vs. 21.5 (19.4) microg.kg-1.h-1,p = 0.0006]. Cardiovascular effects and adverse events could be predicted from the known properties of alpha-2 agonists. In conclusion, dexmedetomidine is a useful agent for the provision of postoperative analgesia and sedation.     

Aortopulmonary window with patent ductus arteriosus and interrupted aortic arch: A case report

Indian Journal of Thoracic and Cardiovascular Surgery -     

Reducing Behavior Problems Among Students with Autism Spectrum Disorder: Coaching Teachers in a Mixed-Reality Setting

Most approaches aiming to reduce behavior problems among youth with Autism Spectrum Disorder (ASD) focus on individual students; however, school personnel also need professional development to better support students. This study targeted teachers’ skill development to promote positive outcomes for students with ASD. The sample included 19 teachers in two non-public special education settings serving students with moderate to severe ASD. Participating teachers received professional development and coaching in classroom management, with guided practice in a mixed-reality simulator. Repeated-measures ANOVAs examining externally-conducted classroom observations revealed statistically significant improvements in teacher management and student behavior over time. Findings suggest that coaching and guided practice in a mixed-reality simulator is perceived as acceptable and may reduce behavior problems among students with ASD.     

Do the morphological characteristics of arteriovenous malformations affect the results of radiosurgery?

OBJECT: The authors sought to determine which morphological features of arteriovenous malformations (AVMs) are statistically predictive of preradiosurgical hemorrhage, postradiosurgical hemorrhage, and neuroimaging-defined failure of radiosurgical treatment. In addition, correlation between computerized tomography (CT) scanning and angiography for the identification of AVM structures was investigated. METHODS: Archived CT dosimetry and available angiographic and clinical data for 268 patients in whom AVMs were treated with linear accelerator radiosurgery were retrospectively reviewed. Many of the morphological features of AVMs, including location, volume, compact or diffuse nidus, neovascularity, ease of nidus identification, number of feeding arteries, location (deep or superficial) of feeding arteries, number of draining veins, deep or superficial venous drainage, venous stenoses, venous ectasias, and the presence of intranidal aneurysms, were analyzed. In addition, a number of patient and treatment factors, including patient age, presenting symptoms, radiation dose, repeated treatment, and radiological outcome, were subjected to multivariate analyses. Two hundred twenty-seven patients were treated with radiosurgery for the first time and 41 patients underwent repeated radiosurgery. Eighty-one patients presented with a history of AVM hemorrhage and 91 patients had AVMs in a periventricular location. Twenty-six patients (10%) experienced a hemorrhage following radiosurgery. Of the 268 patients, 81 (30%) experienced angiographically defined cures, and 37 (14%) experienced MR imaging-defined cures. Eighty-six patients (32%) experienced neuroimaging-defined treatment failure, and 64 underwent insufficiently long follow up. A larger AVM volume (odds ratio [OR] 0.349; p = 0.004) was associated with a decreased rate of pretreatment hemorrhage, whereas periventricular location (OR 6.358; p = 0.000) was associated with an increased rate of pretreatment hemorrhage. None of the analyzed factors was predictive of hemorrhage following radiosurgery. A higher radiosurgical dose was strongly correlated with neuroimaging-defined success (OR 3.743; p = 0.006), whereas a diffuse nidus structure (OR 0.246; p = 0.008) and associated neovascularity (OR 0.428; p = 0.048) were each associated with a lower neuroimaging-defined cure rate. A strong correlation between CT scanning and angiography was noted for both nidus structure (p = 0.000; Fisher exact test) and neovascularity (p = 0.002; Fisher exact test). CONCLUSIONS: Patients presenting with AVMs that are small or periventricular were at higher risk for experiencing hemorrhage. A higher radiosurgical dose correlated strongly with neuroimaging-defined success. Patients in whom the AVM had a diffuse structure or associated neovascularity were at higher risk for neuroimaging-defined failure of radiosurgery. A strong correlation between CT scanning and angiography in the assessment of AVM structure was demonstrated.     

Mechanical loading with or without weight-bearing activity: influence on bone strength index in elite female adolescent athletes engaged in water polo, gymnastics, and track-and-field

Bone health is considered not to benefit from water-based sports because of their weight-supported nature, but available evidence primarily relies on DXA technology. Our purpose was to investigate musculoskeletal health in the upper and lower body in well-trained adolescent female athletes using pQCT and compare these athletes with less-active, age- and sex-matched peers. Bone mineral content, volumetric cortical and trabecular BMD, total and cortical area, and bone strength index were assessed at the distal and proximal tibia and radius in four groups of adolescent females (mean age, 14.9?years) including water polo players (n?=?30), gymnasts (n?=?25), track-and-field athletes (n?=?34), and nonactive controls (n?=?28). Water polo players did not show any benefit in bone strength index or muscle size in the lower leg when compared with controls. In contrast, gymnasts showed 60.1?% and 53.4?% greater bone strength index at the distal and proximal tibia, respectively, than nonactive females (p?相似文献   

The acute effect of magnetic stimulation of the pelvic floor on involuntary detrusor activity during natural filling and overactive bladder symptoms

OBJECTIVE: To evaluate the effect of magnetic stimulation of the pelvic floor (MSPF) on involuntary detrusor activity observed during natural filling, and on the overactive bladder symptom complex. PATIENTS AND METHODS: Eighteen women with detrusor overactivity on conventional cystometry underwent ambulatory urodynamic monitoring over two filling cycles. Fluid intake was standardized, provocative manoeuvres applied at regular intervals and symptoms documented contemporaneously. During the second filling cycle MSPF was delivered whenever the detrusor pressure increased by > 5 cmH2O. The women were subsequently treated with MSPF for 6 weeks; their lower urinary tract symptoms were assessed before and after treatment. RESULTS: Comparing the second (stimulated) cycle with the first (unstimulated) cycle, cystometric capacity was higher (373 vs 224 mL, P < 0.03). and involuntary detrusor activity of shorter duration (370 vs 427 s, P < 0.82) and lower amplitude (53 vs 63 cmH2O, P < or = 0.05). All women tolerated the procedure comfortably, but nine found it too time-consuming and withdrew. In the nine women who completed treatment there was no consistent change in overactive bladder symptoms. CONCLUSIONS: In this pilot study, MSPF during natural filling was associated with a decrease in the amplitude of involuntary detrusor contractions and a significant increase in cystometric capacity. However, MSPF had a variable effect on sensations of urgency, both acutely and after treatment, and currently there is no evidence to suggest that MSPF has an enduring effect on symptoms of the overactive bladder.     

Charlson Co‐morbidity Index and albumin significantly associated with fracture risk in peritoneal dialysis patients

Published literature on fracture in dialysis patients seldom addressed the effect of co‐morbidity and malnutrition. In this study, we reported the incidence and risk factors for fracture in peritoneal dialysis patients. Peritoneal dialysis patients who had fractures between 2006 and 2011 were recruited. Demographic data, details of fracture, Charlson Co‐morbidity Index (CCI) and biochemical parameters were also collected. Non‐fracture controls, matched for age, gender and duration of dialysis, were also recruited at ratio 1:1 for fracture risk analysis. The incidence of fracture was 1 in 37 patient‐years. The commonest site of fracture was neck of femur (n = 16, 55.2%). Twenty‐four patients (82.8%) developed fracture after slip and fall injury. Eight out of 17 self‐ambulatory patients (47.1%) became non‐ambulatory after fracture. Infection was the commonest complication during hospitalization. Univariant analysis demonstrated high CCI (P = 0.001), hypoalbuminaemia (P < 0.001), loss of self autonomy (P = 0.006) and non‐ambulatory state (P = 0.011) significantly associated with increased fracture risk. However, only CCI (odds ratio (OR) 1.373, P = 0.028) and albumin (OR 0.893, P = 0.025) increased fracture risk significantly on multivariant analysis. Bone profile and parathyroid hormone were not significant risk factors. To conclude, fracture associated with adverse outcome in peritoneal dialysis patients. High CCI score and hypoalbuminaemia significantly increase risk of fracture.