Anticipatory Smooth Eye Movements in Autism Spectrum Disorder

Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations.     

One possible way to affect the impurity influx into the plasma of a stellarator with poloidal slits in the vacuum wall

A possible way to affect the influxes of heavy impurities into the plasma of a stellarator with poloidal slits in the vacuum wall (e.g., the W7-AS stellarator) by RF heating of the impurities is discussed. It is shown that the influxes can be reversed in direction by applying a relatively low RF power. The design features of the W7-AS stellarator are such that there is no need to place additional antennas inside the vacuum chamber.     

The enzyme that cleaves apolipoprotein A-II upon in vitro incubation of human plasma high-density lipoprotein-3 with blood polymorphonuclear cells is an elastase

The proteolytic activity directed against apolipoprotein A-II (apo-A-II) which is released from human blood polymorphonuclear cells (PMN) when they are incubated with human plasma high-density lipoprotein-3 (HDL3) was studied to assess the properties and site specificity of the enzyme. When 125I-apo-A-II-labeled HDL3 was incubated with the PMN protease at 37 degrees C, a complete cleavage of apo-A-II was observed which paralleled the formation of bands of approximately 11,000 and 7,000 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 7,000-dalton component had the following N-terminal sequence: NH2-Thr-Asp-Tyr-Gly-Lys-Asp-Leu-Met-Glu-Lys. This corresponds to residues 19 through 28 of the intact apo-A-II monomer. Methoxysuccinyl (MeO-Suc)-Ala-Ala-Pro-Val-chloromethylketone-(CH2Cl) caused a 90% inhibition of apo-A-II hydrolysis at the highest concentration tested (6 X 10(-4)M). Besides apo-A-II, the PMN enzyme also hydrolyzed a synthetic substrate, MeO-Suc-Ala-Ala-Pro-Val-4-nitroanilide and its 4-methylcoumaryl-7-amide analogue. The protease appeared to have a mass of 28,000 daltons as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the [3H]diisopropylfluorophosphate-labeled PMN enzyme. That the PMN enzyme which cleaves apo-A-II is an elastase was derived from the following criteria: 1) cleavage at the Val-X bond in apo-A-II and in the two synthetic substrates studied; 2) prevention of the cleavage by MeO-Suc-Ala-Ala-Pro-Val-CH2Cl, a known specific elastase inhibitor; and 3) a mass comparable to that reported for a pure PMN elastase. These studies establish that apolipoproteins can be suitable substrates for enzymes of the elastase family.     

Protonic and cationic changes during cyclical cation transport driven by electron transfer

A method is described for the subcellular fractionation of goldfish xanthophores. The procedure produces relatively pure fractions of caroteniod droplets, pterinosomes, cytosol and what appears to be plasma membrane. The presence of a distinct pattern of proteins is shown to be associated with the carotenoid droplets. Treatment of the xanthophores with ACTH affects the buoyant density of some carotenoid droplets and stimulates the phosphorylation of a polypeptide associated with the carotenoid droplets.     

An in vivo/in vitro evaluation of teratogenic action

Several compounds were administered to pregnant Wistar-derived rats either 24 or four hours prior to the recovery of day 10 embryos for in vitro culture in Waymouth's medium and fetal calf serum. The compounds tested were 2-amino-1,3,4-thiadiazole (thiadiazole), cadmium sulfate, 1,2-dibromo-2,2-dichloroethyl dimethyl phosphate (dibrom), 2-(sec-Butyl)-4,6-dinitrophenol (dinoseb), led nitrate, polybrominated biphenyls (PBB), sodium arsenate, and trypan blue. After 24 hours in culture, two thirds of the embryos were recovered for examination. The remaining one third were continued in culture until 42 hours. Recovered embryos were examined for rotation of the embryonic axis, heart rate, establishment of the visceral yolk sac circulation, somite number, growth of the limb buds, closure of the neural tube, and development of the allantois and amnion. All tested compounds inhibited the rate of development in vitro.     

Massive deformation of the scrotal wall by idiopathic calcinosis of the scrotum

Idiopathic calcinosis of the scrotum is a rare disease that may cause massive deformation of the scrotal wall. The first patient we present was also known to have neurofibromatosis. In the second patient we describe, nodules of idiopathic calcinosis of the scrotum were seen with walls that evidenced no epithelial lining, as well as calcification in epithelial cysts. At present, the only possible treatment is excision, and we excised the afflicted skin without problems in primary wound closure.