Perception during double-step saccades.

How the visual system achieves perceptual stability across saccadic eye movements is a long-standing question in neuroscience. It has been proposed that an efference copy informs vision about upcoming saccades, and this might lead to shifting spatial coordinates and suppressing image motion. Here we ask whether these two aspects of visual stability are interdependent or may be dissociated under special conditions. We study a memory-guided double-step saccade task, where two saccades are executed in quick succession. Previous studies have led to the hypothesis that in this paradigm the two saccades are planned in parallel, with a single efference copy signal generated at the start of the double-step sequence, i.e. before the first saccade. In line with this hypothesis, we find that visual stability is impaired during the second saccade, which is consistent with (accurate) efference copy information being unavailable during the second saccade. However, we find that saccadic suppression is normal during the second saccade. Thus, the second saccade of a double-step sequence instantiates a dissociation between visual stability and saccadic suppression: stability is impaired even though suppression is strong.

HIV-associated immune complex glomerulonephritis with "lupus-like" features.

Renal structural abnormalities in HIV/AIDS infected patients have been infrequently and incompletely reported in patients from sub-Saharan Africa. We report an immune complex glomerulonephritis with "lupus-like" features in a ten-year-old HIV+ boy who was evaluated at the University Hospital of Kinshasa. The light microscopic examination of the renal biopsy displayed a predominantly membranoproliferative glomerulonephritis with prominent focal segmental necrotizing injury, numerous wire-loops, and a spiky membranous nephropathy. In addition, there were prominent tubular injury, microcysts filled with periodic acid-Schiff (PAS) positive casts, edema and an inflammatory infiltrate of the interstitium, features of a classic HIV-associated nephropathy (HIVAN). Electron microscopy revealed large subendothelial, intra-membranous, subepithelial and mesangial deposits. The combination of these findings, while being consistent with lupus nephritis WHO grade IV/V, the tubulointerstitial HIVAN-like changes and the absence of clinical evidence of lupus disease favored an HIV-associated immune complex glomerulonephritis with "lupus-like features".

[Evaluation of blood flow using a reservoir flowmeter of several types of arteriovenous fistulas in chronic hemodialysis treatment]. / Valutazione del flusso ematico di alcuni tipi di fistole artero venose per il trattamento emodialitico cronico mediante "flussi metria a pozzetto".

Blood flow of nine end to end and eight side to side arteriovenous fistulas (AVF) at distal forearm for maintenance hemodialysis, was measured by blood flowmeter inserted in the arterial line between the pump and the dialyzer. The mean flow of the end to end and the side to side fistulas was 386.6 +/- 69.6 ml/min and 345 +/- 45 ml/min (p 0.01) respectively. Since, in addition, the end to end flow seems to be better than the side to side flow as regards local and general effects, we advocate the use of end to end fistulas.

[Behavior of plasma enteroglucagon and neurotensin in obese patients subjected to biliopancreatic bypass]. / Comportamento dell'enteroglucagone e della neurotensina plasmatici in soggetti obesi sottoposti a bypass biliopancreatico.

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-Y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis place 50 cm proximal to the ileocecal valve. Neurotensin and enteroglucagon fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 11 subjects within two months, in 12 subjects four to twelve months and in 7 subjects fifteen to twenty months after operation. Basal plasma enteroglucagon was significantly higher in the obese group than in the controls. However, there was no difference in the peak response, and a decrease, though not statistically significant, was seen in the integrated response. All three values were strikingly augmented in the 0-2 month group, with a highly significant difference from the preoperative group. The 4-12 and 15-20 month groups, in comparison with the 0-2 month group, showed no changes in fasting levels, a clear-cut decreased peak response and a sharp progressive reduction in integrated response, mean value in the 15-20 month group being significantly lower than that of 0-2 month group. Neurotensin basal and meal-stimulated peak plasma concentrations in the obese group were significantly higher than in the control group, whilst the integrated response was almost identical in the two groups. In postoperative groups no substantial changes in fasting levels and an increase in the peak response were observed, with a considerable progressive rise in the integrated response.

[Behavior of plasma pancreatic polypeptides and motilin in obese patients subjected to biliopancreatic bypass]. / Comportamento del polipeptide pancreatico e della motilina plasmatici in soggetti obesi sottoposti a bypass biliopancreatico.

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis placed 50 cm proximal to the ileocecal value. Pancreatic polypeptide (PP) and motilin fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 9 subjects within two months, in 12 subjects four to twelve months, and in 7 subjects fifteen to twenty months after operation. There were no significant differences in PP fasting levels between either the obese and control groups or between the postoperative groups and the preoperative group. Both meal-stimulated peak and integrated response values were similar in the obese and control groups, and were strikingly and progressively reduced postoperatively, with statistically significant difference between all postoperative groups and preoperative group. Mean plasma motilin fasting and peak values were higher in the obese group than in the control group, and significantly reduced in the 4-12 and 15-20 month group. Despite the huge variability among data, the integrated response in the 0-2 month group was significantly decreased in comparison with the preoperative group, while a subsequent progressive increase was shown by the 4-12 and 15-20 month groups.