Analog language teaching versus natural language teaching: Generalization and retention of language learning for adults with autism and mental retardation

Examined the effects of two instructional methods on language generalization and longterm retention in 23 adults with autism and severe to profound mental retardation. Analog language teaching employed discrete trials in a controlled setting concentrating on discrimination and identification of materials. Natural language teaching emphasized instruction through interactions that occurred incidentally to training students in the use of materials to perform functional tasks. Assessments were conducted under conditions favoring analog teaching to assure against partiality toward natural language teaching. Under such disadvantageous conditions, the methods of natural language teaching would be supported by results showing either no difference or an advantage in their favor. Both techniques increased initial and long-term generalization though the results suggest no relative superiority for either method under these assessment conditions. A significant interaction was found between prior functioning level and sequence of instruction. Because natural language teaching has many strengths, few drawbacks, and produces equal generalization and retention under disadvantageous conditions, it is strongly supported as preferable for people with autism and mental retardation.The authors acknowledge the important assistance provided by the following people: the staff and management of the Behavior Development and Learning Center at CSH/DC directed by Israel Perel, Lisa Kramer, Steve Hafferkamp, James Lowdermilk, and, finally, and especially, to the participants themselves.     

Increased GABAergic transmission aggravates nucleus basalis magnocellularis lesion-induced behavioral deficits

Quisqualic acid NBM lesions had no effect on water maze performance, but slightly impaired passive avoidance acquisition. GammavinylGABA treatment alone had no effect on the passive avoidance and water maze performance, but aggravated acquisition deficit in rats subjected to NBM lesioning. However, gammavinylGABA-treated NBM-lesioned rats reached control level of performance.     

The effects of THA on scopolamine and nucleus basalis lesion-induced EEG slowing

The effectiveness of THA (an anticholinesterae) on scopolamine (0.4 mg/kg) and nucleus basalis (NB) lesion-induced change in neocortical spectral electroencephalography (EEG) were investigated. Scopolamine increased the amplitudes of all the spectral components in waking-immobility. In the movement-related EEG spectral values, only the alpha power was increased. THA 7.5 mg/kg, but not THA 3 mg/kg, could reverse scopolamine-induced amplitude change. NB lesioning increased delta and theta amplitudes, but decreased beta amplitude. Delta amplitude was increased during movement recordings in NB-lesioned rats. THA 7.5 mg/kg and pilocarpine 10 mg/kg, but not THA 3 mg/kg, could partially reverse the increase of delta and theta amplitudes induced by NB lesions. However, the beta power decrease could not be restored with cholinomimetics. This study demonstrates that quantitative EEG activity analysis may reflect the THA-induced restoration of the function of the cholinergic nucleus basalis.     

Caffeine and light effects on nighttime melatonin and temperature levels in sleep-deprived humans

The effects of caffeine ingestion and exposure to bright light, both separately and in combination, on salivary melatonin and tympanic temperature were assessed in humans. Four treatments during a 45.5 h sleep deprivation period were compared: Dim Light-Placebo, Dim Light-Caffeine, Bright Light-Placebo and Bright-Light Caffeine. The Dim Light-Caffeine condition (200 mg twice each night) relative to the Dim Light-Placebo condition suppressed nighttime melatonin levels and attenuated the normal decrease in temperature. Combining caffeine ingestion with bright light exposure (≥2000 lux) suppressed melatonin and attenuated the normal nighttime drop in temperature to a larger degree than either condition alone; i.e. effects were additive. Circadian effects were also observed in that the amplitude and phase of the temperature rhythm were altered during treatment. These findings establish that the human melatonin system is responsive to caffeine. Other evidence suggests that caffeine may influence melatonin and temperature levels through antagonism of the neuromodulator adenosine.     

Functional anatomy and biomechanics of the meniscus

The meniscus is no longer considered the evolutionary remnant in the knee joint.Rather, it is now well established as an important structure that is integral to the complex biomechanics and proper functioning of the knee. The medial and lateral menisci form two crescent-shaped wedges of fibrocartilage between the femoral condyles and tibial plateaus.The knee joint biomechanics are based on a complex interaction of these intra-articular structures. The functions ascribed to the menisci include load transmission, shock absorption, stability, proprioception, joint lubrication, and joint nutrition. Load transmission generally is accepted as one of its primary functions. The menisci transmit a portion of the axial forces across the knee joint by converting this load into “hoop stresses.” This is accomplished by their unique shape, composition, and anatomic attachments. The menisci are relatively mobile structures and their motion during knee flexion also is determined by their shape and soft tissue attachments/constraints. Preservation of the meniscal functions is essential, and the authors review the basic anatomic and biomechanical concepts necessary to understand techniques for repair and restoration of these functions.     

Technetium-99m sestamibi scintigraphy for the assessment of lower extremity ischaemia in peripheral arterial disease

Technetium-99m sestamibi was used for functional investigation of the muscle perfusion of lower extremities in 35 patients with peripheral vascular disease. The aim was to test what useful information could be obtained by additional imaging of the legs in patients referred for risk stratification with dipyridamole myocardial scanning. Posterior images were acquired over the thighs and calves after postocclusive reactive hyperaemia and at rest. Inter- and intraextremity ratios and differences between the stress and rest data were used for the assessment of abnormal circulation. Arteriography was performed in every case, and surgical procedures or transluminal angioplasty in 31 patients. To estimate diagnostic accuracy, the results of^99mTc-sestamibi scintigraphy were compared with those of angiography and the functional consequences of revascularization procedures. The sensitivity and specificity of^99mTc-sestamibi scintigraphy were 55% and 25%, respectively, with an overall accuracy of 50%. Apparently methodological error was not responsible for these poor results. Instead, a paradoxically high uptake of the radiopharmaceutical in muscles supplied by significantly stenosed vessels was identified as the main source of both false-negative and false-positive results. This phenomenon resembles the findings of a previous study involving delayed administration of thallium-201 after exercise. In conclusion,^99mTc-sestamibi scintigraphy has not proved sufficiently reliable to help in the management strategy for patients with peripheral vascular disease.