Visual attention to surfaces in three-dimensional space.

Although attention plays a significant role in vision, its spatial deployment and spread in the third dimension is not well understood. In visual search experiments we show that we cannot easily focus attention across isodepth loci unless they are part of a well-formed surface with locally coplanar elements. Yet we can easily spread our attention selectively across well-formed surfaces that span an extreme range of stereoscopic depths. In cueing experiments, we show that this spread of attention is, in part, obligatory. Attentional selectivity is reduced when targets and distractors are coplanar with or rest on a common receding stereoscopic plane. We conclude that attention cannot be efficiently allocated to arbitrary depths and extents in space but is linked to and spreads automatically across perceived surfaces.     

Application of anterior pituitary cell culture in toxicological research.

High density plating procedure was used to evaluate the effect of atrazine on anterior pituitary cells of rats in monolayer culture. Collagenase-dispersed pituitary cells plated in suspension with medium-199 and 10% foetal calf serum attached quantitatively to plastic surfaces within 24 hours. Electron microscopy showed subpopulations of different cell types. After prolonged cultivation, most cells established small colonies with extensive contacts among them. Cell-to-cell formation of aggregates was significant and the colonies manifested morphological changes. The cells retained their enzymatic activity, converting testosterone into 5 alpha-dihydrotestosterone by enzyme 5 alpha-reductase. Immunohistochemical techniques facilitated differentiation of gonadotrophs producing follicle stimulating hormone (FSH) and luteinising hormone (LH). Atrazine in concentrations of 5 to 50 micrograms/ml of medium was associated with a significant reduction in the number of viable cells within 72 hours. The results suggest that the pituitary cell culture may prove useful in toxicological testing of various toxic compounds and reduce or replace in vivo animal experiments.     

Cytokines and adhesion molecules in renal vasculitis and lupus nephritis

Background: Plasma levels of some pro-inflammatory cytokines and soluble adhesion molecules have been suggested to be useful parameters to assess the activity of antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis and lupus nephritis. We hypothesized that the renal activity of these diseases is better reflected by the urinary excretion and fractional excretion of these molecules. Methods: Plasma levels and urinary excretion of tumour necrosis factor-&agr; (TNF-&agr;), interleukin (IL)-6, IL-8, and the soluble cell adhesion molecules sICAM-1 and sVCAM-1 were measured by enzyme-linked immunosorbent assay (ELISA) in 15 patients with ANCA-positive renal vasculitis (eight active, ANCA-A; six in remission, ANCA-R), six patients with active lupus nephritis (LN), 15 patients with IgA nephropathy (IgAN) and nine healthy subjects. Fractional excretion of selected cytokines and adhesion molecules was also calculated. Results: Patients with ANCA-A had increased urinary excretion and fractional excretion of TNF-&agr; (9.27±3.19% vs 0.58±0.02%, P<0.01), IL-6 (120.79±65.83% vs 1.89±0.34%, P<0.01) and increased fractional excretion of IL-8 (23.34±6.38% vs 2.56±1.07%, P<0.01) and sVCAM-1 (0.81±0.33% vs 0.03±0.02%, P<0.01) compared with controls. Urinary excretion of TNF-&agr; and IL-6 and fractional excretion of TNF-&agr;, IL-6 and IL-8 were higher in ANCA-A than in ANCA-R. Patients with LN had increased plasma TNF-&agr; (20.52±2.01 pg/ml vs 12.33±0.23 pg/ml, P<0.05) and sVCAM-1 (1537.88±276.36 ng/ml vs 692.26±44.42 ng/ml, P<0.05) and increased urinary excretion of TNF-&agr; (2.81±0.51 &mgr;g/mol creat vs 0.98±0.05 &mgr;g/mol creat, P<0.01), IL-8 (35.78±14.03 &mgr;g/mol creat vs 12.46±5.19 &mgr;g/mol creat, P<0.05) and sVCAM-1 (48.98±20.20 &mgr;g/mol creat vs 2.92±1.35 &mgr;g/mol creat, P<0.01) compared with controls. Patients with IgAN had, in comparison with controls only increased plasma TNF-&agr; (18.10±0.57 pg/ml vs 12.33±0.23 pg/ml, P<0.05). Conclusions: Urinary excretion and fractional excretion, but not plasma levels of selected proinflammatory cytokines (TNF-&agr;, IL-6 and IL-8) were increased in patients with active ANCA-positive renal vasculitis, but not in ANCA positive vasculitis in remission. These parameters may be useful to monitor the activity of this disease.     

Averaged axillary F-loop latency of median and ulnar nerves

Axillary F-loop latencies (AFLL) were measured on median and ulnar nerves of 54 normal volunteers. The median and ulnar nerves were stimulated at the wrist and at the axilla 25cm distal to the sternal notch. The compound muscle action potentials were recorded from thenar and hypothenar muscles. Averaged tracings from 32 consecutive stimuli at the wrist were obtained. The averaged F-wave latencies were measured to the peak (Fwp) of the averaged F-wave. The M-wave latencies from wrist and axilla stimulation were measured to the onset of the wave (Mw and Ma, respectively). The averaged AFLL (a-AFLL) was calculated as (Fwp + Mw)-2 Ma. The average values of a-AFLL were 14.12 +/- 0.88msec for median nerve, and 13.97 +/- 0.90msec for ulnar nerve. There was no significant difference between male and female subjects, nor between the right and left sides. Seven subjects with EMG evidence of C8 or C8 to T1 radiculopathy, although manifesting normal AFLL gauged by the regular method (ie, measured to the onset of the shortest F-wave latency among eight tracings), had significantly longer "averaged AFLL" in both median and ulnar nerves of the affected side than the a-AFLL obtained from the normal side. It is concluded that the a-AFLL is a more sensitive measure than the "regular AFLL" in the assessment of proximal nerve lesion (especially C8 or C8 to T1 radiculopathy).     

Alcohollike liver disease in nonalcoholics. A clinical and histologic comparison with alcohol-induced liver injury

Individuals who deny alcohol consumption may develop liver injury that histologically resembles the liver injury found in alcoholic patients. To determine whether any clinical or histologic features distinguish alcoholic and nonalcoholic subjects with "alcohollike" liver injury, the clinical records and liver biopsy specimens of 68 alcoholic and 39 nonalcoholic patients with alcohollike injury on liver biopsy were compared. The clinical and biochemical features of the two groups differed significantly. Alcoholism was associated with more severe clinical and biochemical manifestations of liver disease. However, there was considerable overlap among histologic features of the two clinically defined groups. Based on histology alone, alcoholic and nonalcoholic patients were often indistinguishable. The observations suggest that the clinical differences between the alcoholic and non-alcoholic patients cannot be attributed to qualitative or quantitative differences in liver histology. On the other hand, histologic similarities between the two groups raise the possibility that a shared condition, perhaps nutritional or hormonal, is responsible for the histologic expression of alcohollike injury in both groups.     

Patterns of calcifications and cholangiographic findings in hepatobiliary tuberculosis

The radiologic findings on conventional examinations (plain films and cholangiograms) in a large group of patients with proven hepatobiliary tuberculosis are reviewed. The plain film findings of large chalky and confluent hepatic calcifications or nodal-type calcifications along the course of the common bile duct are suggestive of hepatobiliary tuberculosis. Small, discrete, scattered calcifications may be mimicked by histoplasmosis but can be differentiated from hepatobiliary tuberculosis. Obstructing defects seen on cholangiography are indicative of tuberculosis when adjacent calcifications are present. The patterns of liver calcifications could provide a clue to the diagnosis of hepatobiliary tuberculosis and its differentiation from liver calcifications of various other etiologies.     

Development and clinical evaluation of immunoluminometric assays for lactoferrin and elastase-alpha 1-proteinase inhibitor complexes in body fluids with special references to bronchoalveolar lavage and neonatal sepsis

Immunoluminometric assays for lactoferrin and elastase-alpha 1-proteinase inhibitor complexes were developed using solid-phase methodology, which has already been published from this laboratory. The aim of the study was to develop a rapid method to see whether elevated granulocyte activity was present in the lung, as for example in neonatal sepsis. The lactoferrin assay gave reliable results within 30 minutes, the elastase-alpha 1-proteinase inhibitor complexes, within 5 hours. The correlation between both analytes was good, so that the lactoferrin assay could replace the elastase-alpha 1-proteinase inhibitor assay in emergency cases. The lactoferrin assay was used for rapid answer, the elastase-alpha 1-proteinase inhibitor complex assay for "fine" monitoring of the progress of the disease. Both assays could be used to measure concentrations in plasma or bronchoalveolar lavage using a 10 microliters sample. Plasma for the elastase-alpha 1-proteinase inhibitor complex determination had to be diluted 1:50 before being assayed. Only EDTA plasma was used in the assay, as either heparin plasma or serum resulted in granulocyte destruction, thus giving rise to elevated, and non-reproducible results. The results from bronchoalveolar lavage show an excellent correlation between elastase-alpha 1-proteinase inhibitor complexes and lactoferrin. No interference was seen from lipaemic or icteric plasma samples. Results from haemolytic samples i.e. where lysis of erythrocytes and leukocytes had occurred, had to be treated with care if no clinical indication of intravascular haemorrhage was present. The assays lend themselves to perinatal diagnosis, as the total volume of plasma or lavage needed is theoretically under 50 microliters, i.e. ethically acceptable for regular monitoring of neonates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of pathology of the urinary system in students during preventive mass screening

Screening tests including the questionnaire method, urine analysis and radiorenography were used during mass screening of 1330 students. Comparison of the results of the first two methods showed a good informative value of the questionnaire method for the detection of pathology of the kidneys and urinary tracts. Radiorenography performed in 106 students with the detected nephrological symptom complex (risk group) revealed some changes practically in every other "risk group" student.