Morphologie

Ohne Zusammenfassung     

Epstein-Barr virus coopts lipid rafts to block the signaling and antigen transport functions of the BCR

The B cell antigen receptor (BCR) functions to initiate signaling and to internalize antigen for processing from within Lyn kinase-enriched membrane lipid rafts. The signaling function of the BCR is blocked by Epstein-Barr Virus (EBV) latent membrane protein 2A (LMP2A), which is constitutively phosphorylated by Lyn. Here, we show that LMP2A resides in lipid rafts and excludes the BCR from entering rafts by Lyndependent mechanisms, thus blocking both BCR signaling and antigen transport. Mutant LMP2A that permits BCR signaling and raft translocation still blocks antigen trafficking, indicating independent control of these BCR functions. Thus, EBV coopts the lipid rafts to disarm both the signaling and antigen-processing functions of the BCR by independent mechanisms.     

Pediatric rehabilitation. 6. Musculoskeletal and soft tissue disorders

This self-directed learning module highlights advances in evaluation and treatment of congenital and acquired musculoskeletal disorders in the child. It is a section of the chapter on pediatric rehabilitation for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. This section contains information on alterations of limb structure and gait, scoliosis, torticollis, sports injuries and overuse syndromes, and unexplained pain in children.     

Interactions between mu and kappa opioid agonists in the rat drug discrimination procedure

The present study was designed to explore the nature of the interaction between mu and kappa opioid agonists in the rat drug discrimination procedure. In rats trained to discriminate the kappa agonist U50,488 (5.6 mg/kg) from water, the other kappa agonist bremazocine substituted completely for the U50,488 training stimulus, and the additional kappa agonist tifluadom substituted in three of five of rats tested. In contrast, the mu agonists morphine, fentanyl, and buprenorphine produced primarily vehicle-appropriate responding. When morphine, fentanyl, and buprenorphine were combined with the training dose of U50,488, all three mu agonists reduced U50,488-appropriate responding. In rats trained to discriminate the mu agonist morphine (10.0 mg/kg) from saline, the other mu agonists morphine and buprenorphine all substituted in a dose-dependent manner for the morphine training stimulus, whereas U50,488, bremazocine, and tifluadom produced primarily vehicle-appropriate responding. When combined with the training dose of morphine, bremazocine antagonized morphine's discriminative stimulus effects, whereas U50,488 and tifluadom had no effect. The barbiturate pentobarbital neither substituted for, nor antagonized, the discriminative stimulus effects of either U50,488 or morphine. These results suggest that mu agonists and kappa agonists produce interacting effects in the drug discrimination procedure in rats.     

Pediatric rehabilitation. 1. General principles and special considerations

This self-directed learning module addresses core concepts in the assessment of any child with disability, including physical growth and development, evolution of reflexes, and cognitive and personality development. It is a section of the chapter on pediatric rehabilitation for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. The rehabilitation perspective is emphasized, especially as it changes to accommodate the developing child, with a focus on specific chronic disorders such as respiratory disease, congenital heart disease, and malignancy. These types of disorders serve as a model for the management of problems that require special medical, rehabilitative, and psychosocial consideration.     

Antagonism of morphine by long acting narcotic antagonists

Thirty-six female albino rats, trained to run for a chocolate reward in a circular runway, were treated according to 6×6 Latin square schemes with five doses of 3-quinuclidinylbenzilate, ranging from 0.1 to 10 mg/kg, or the vehicle. On experimental days there were 6 consecutive trials. Intraperitoneal injections were administered 20 min before the first trial. The apparatus was automated as far as the opening of sliding doors and the recording of the duration of running, subdivided into latency and running-time, were concerned. Along with the duration of running, the behaviour shown in the various parts of the maze was analysed. The drug caused a marked, dose-dependent increase of the latency, whereas the effect on running-time was comparatively small. During the latency the frequency of ambivalent behaviours, shown at the transition of the start-goal compartment and the runway, increased under the influence of 1 mg/kg or more. Concomitant increases were noted in the frequency of displacement activities, which were absent in control animals. The results were interpreted as a drug-induced intensification of a conflict, existing in normal animals between the tendency to stay in the vicinity of the reward and the tendency to run for a subsequent reward.     

Antagonism of Etonitazene's effects in rats and pigeons

The effects of etonitazene were studied in the pigeon under a mult FR FI schedule of food presentation and in the rat under a continuous avoidance-escape schedule. A low dose of etonitazene increased rates of responding by pigeons under the FI component of the multiple schedule, whereas higher doses produced dose-related decreases in rates of responding under both components of the multiple schedule. These effects were blocked by cyclazocine. Under the continuous avoidance-escape schedule, etonitazene produced only dose-related decreases in rates of responding by rats, and these decreases were blocked by naloxone.     

The effects of morphine and scopolamine on auditory discrimination in squirrel monkeys

In squirrel monkeys trained to discriminate between two tones, morphine consistently increased the percent of response failures during tone periods; however, it had no consistent effect on the percent correct responses. In contrast, scopolamine decreased percent correct responses as well as increasing percent response failures in two monkeys not required to respond to produce the tone periods. In the two monkeys required to initiate tone periods by responding, high doses of scopolamine reduced the number of tones presented.