DNA-antibodies in sera from patients with systemic lupus erythematosus

DNA-antibody determinations using the Farr technique and LE cell tests were performed on single serum samples from 55 patients with SLE according to well defined criteria. It was found that the DNA-antibody test was just as sensitive as the LE cell test, and studies of sera from patients with questionable SLE, discoid LE, other connective-tissue diseases, psoriasis, and from healthy persons, indicated that the DNA-antibody test is highly specific for SLE. Neither the DNA-antibody test nor the LE cell test could discriminate between SLE patients with active and inactive disease as estimated by clinical criteria or by the serum concentrations of complement C3 and C4.

A randomized trial of etretinate (Tigason) in palmoplantar pustulosis

5 patients with palmoplantar pustulosis (PPP) were randomized to 8 weeks of daily treatment with either oral etretinate, 1 mg/kg b.w. or placebo. Good or moderate effect was obtained in 18 or 20 patients on etretinate compared o 6 of 21 patients on placebo (p less than 0.001). Etretinate proved to be significantly superior to placebo with regard to influence on the individual symptoms and signs of pustulosis. All patients on etretinate experienced some side effects from the mucous membranes, but they were generally mild. Treatment was discontinued after 4 weeks in 3 patients for reasons unrelated to treatment, in 4 for lack of effect (all on placebo) and in 2 for side effects (both or etretinate). Etretinate is a good alternative to other systemic treatments of PPP.

Episodic arthritis, skin manifestations and immune complexes following intestinal by-pass operations for morbid obesity

A systematic search for immune complexes (IC) in blood and skin revealed no correlation to IC-related disorders in 35 patients who had undergone jejunoileal bypass for obesity. Tests for cryoprecipitates and endotoxins proved negative.

Adaptation and gain normalization

It has been suggested in the past that adaptation effects may serve a useful role in perception. This paper shows that if the adaptation process follows a simple scheme, called proportional gain adjustment, then it can fulfil two useful functions: correction of errors and recalibration. The proposed scheme controls the gain of the system. Although it is memoryless, it ensures a setting of the gain at such a level that the average of the measured signal in the environment is always mapped onto a fixed internal representation. The proportional gain adjustment scheme is discussed in the context of single-band multi-channel models, and is shown to exhibit various phenomena associated with visual adaptation.

The lupus band test as a measure of disease activity in systemic lupus erythematosus

One hundred twenty-seven biopsy specimens from clinically normal light-protected skin of 88 patients with active and inactive lupus erythematosus (LE) were examined for deposits of IgG, IgM, IgA, and C3 at the dermal-epidermal junction (DEJ). Deposits were found in 91% of those with active disease and in 33% of those with inactive disease. The finding of such deposits reflected active disease just as did a decrease in serum C3 and C4 levels, elevated anti-double-stranded DNA, the presence of LE cells, lymphopenia, and an elevation of the ESR. The presence or absence of deposits in repeated biopsy specimens indicated changing disease activity, as estimated clinically, just as did changes in the other variables mentioned. Neither immunoreactants in skin nor any other laboratory abnormality reflected renal disease or other type of organ involvement. Deposits of IgG were not more commonly found in patients with renal disease.

Treatment of chlamydial urethritis in men and Chlamydia trachomatis-positive female partners: comparison of erythromycin and tetracycline in treatment courses of one week

Seventy-one consecutive men who had Chlamydia trachomatis-positive nongonococcal urethritis were assigned randomly to treatment for one week with either tetracycline or erythromycin (1g daily). Seventy men completed the study. At follow-up, there were two therapeutic failures among 36 patients treated with erythromycin, and two failures among 34 patients treated with tetracycline. Twenty-four C. trachomatis-positive female contacts were randomly assigned to treatment regimens similar to those of the men. There was one treatment failure among 12 women treated with erythromycin, and no failure among 12 treated with tetracycline. In this study the urethral smears contained fewer than five leukocytes per high-power field in 16% of the C. trachomatis-positive men with symptoms suggestive of urethritis.

A model for the temporal organization of X- and Y-type receptive fields in the primate retina

A model is proposed for the temporal characteristics of X- and Y-type responses of ganglion cells in the primate retina. The main suggestions of the model are: (I) The X-type temporal response is determined primarily by the delay between center and surround contributions. (II) The Y-type response is generated in the inner plexiform layer by a derivative-like operation on the bipolar cell's input, followed by a rectification in the convergence of these inputs onto the Y-ganglion-cell. (III) The derivative-like operation is obtained by recurrent inhibition in the dyad synaptic structure. The X- and Y-type responses predicted by the model, for a variety of stimuli, were examined and compared with available electrophysiological recordings. Finally, certain predictions derived from the model are discussed.

Deposits of immunoglobulins, complement, and fibrinogen in oral lupus erythematosus, lichen planus, and leukoplakia

Direct immunofluorescent staining (IF) for detection of deposits of IgG, IgM, IgA, complement C3, and fibrinogen at the basement membrane zone has been performed on a total of 279 biopsy specimens from oral lesions and clinically normal oral mucosa from the following groups of patients: fourty-five discoid lupus erythematosus (DLE), including sixteen patients without skin lesions, seven systemic lupus erythematosus (SLE); fourty-five lichen planus (LP); thirty leukoplakia (Leuk.); twenty patients with uncertain diagnosis, termed DLE? LP?; and twenty-three healthy persons. Deposits of immunoglobulins (lg) occurred in 73 percent of oral lesions in DLE and in 100 percent of the oral lesions in SLE, whereas lg deposits occurred in 3 to 30 percent in the other groups, the differences being significant (P less than 0.05). It is concluded that lg deposits are a characteristic feature of oral lesions of DLE and SLE and only rarely occur in oral lesions of LP and Leuk., which are the most important differential diagnoses. A direct immunofluorescence test on oral lesions suspected to be LE should be regarded as positive only if lg deposits are present, since C3 occurs frequently in oral lesions other than LE. Consideration can be given to the inclusion of lg deposits in the diagnostic criteria for oral LE lesions.

Directional selectivity and its use in early visual processing

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of delta 2G (x,y) * I(x,y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative delta[delta 2G(x,y) * I(x,y)]/delta t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180 degrees. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.

The effect of similarity between line segments on the correspondence strength in apparent motion

The correspondence between line segments in apparent motion is shown to be affected by the similarity between them. Increase in orientation difference or in length ratio between lines in a competing motion configuration decreases the probability of perceived apparent motion between them. The results suggest the existence of a built-in preference metric that may reflect a measure of matching likelihood between elements in three-dimensional space.

Deposits of immunoglobulin and complement in psoriatic lesions

Biopsy specimens from 43 patients with psoriasis were studied by immunofluorescence microscopy. Deposits of complement C3 and/or immunoglobulins were seen in the vessel walls and/or in the dermal-epidermal junction of all of 21 patients with pustular psoriasis, acute guttate psoriasis, psoriatic arthropathy and erythroderma. similar deposits were seen in nine out of 22 patients with psoriasis vulgaris. Deposits were found in clinically uninvolved skin in only one of 37 patients. The results might suggest that the deposition of immune complexes in the vessel walls are of importance for the development of psoriatic lesions.

Dermatitis herpetiformis and gluten-sensitive enteropathy in monozygotic twins

Of two monozygotic twins, one had dermatitis herpetiformis, while the other had gluten-sensitive enteropathy. The literature on twins is reviewed.

Pemphigus vulgaris and pemphigus foliaceus coexisting with oral lichen planus

Two women, aged 72 and 61 years, had mucocutaneous manifestations of pemphigus vulgaris, and one 76-year-old man had pemphigus foliaceus coexisting with oral lichen planus. Clinical and histopathological findings as well as direct and indirect immunofluorescence studies established the diagnosis.

Bandpass channels, zero-crossings, and early visual information processing

Under appropriate conditions zero-crossings of a bandpass signal are very rich in information. The authors examine here the relevance of this result to the early stages of visual information processing, where zero-crossings in the output of independent spatial-frequency-tuned channels may contain sufficient information for much of the subsequent processing.

The interpretation of structure from motion

The interpretation of structure from motion is examined from a computional point of view. The question addressed is how the three dimensional structure and motion of objects can be inferred from the two dimensional transformations of their projected images when no three dimensional information is conveyed by the individual projections. The following scheme is proposed: (i) divide the image into groups of four elements each; (ii) test each group for a rigid interpretation; (iii) combine the results obtained in (ii). It is shown that this scheme will correctly decompose scenes containing arbitrary rigid objects in motion, recovering their three dimensional structure and motion. The analysis is based primarily on the "structure from motion" theorem which states that the structure of four non-coplanar points is recoverable from three orthographic projections. The interpretation scheme is extended to cover perspective projections, and its psychological relevance is discussed.

Deposits of immunoglobulins and complement in skin of patients with rheumatoid arthritis. Influence of anti-rheumatic treatment

Immunopathological studies on skin biopsies from 88 patients with rheumatoid arthritis showed that one-third of them had deposits of IgM and/or C3 in the walls of small vessels immediately underneath the dermal-epidermal junction. The deposits in the vessel walls which may reflect subclinical immune complex vasculitis could be correlated to the occurrence of IgG-rheumatoid factor in the serum, but not to IgM-rheumatoid factor, other extra-articular manifestations, or to the occurrence of circulating immune complexes demonstrated by the complement consumption test or the thrombocyte aggregation test. Two untreated patients had granular deposits in the dermal-epidermal junction. Five out of 50 patients developed deposits in the dermal-epidermal junction during treatment with levamisole, penicillamine, or azathioprine, as observed by serial skin biopsies.

Two dimensionality of the correspondence process in apparent motion

A fundamental process underlying motion perception is the matching of corresponding elements in different views. In this correspondence process spatial separation between elements plays a major role. The relevant separation is shown by the current study to be the two-dimensional, uninterpreted distance, a finding that has an implication to the level at which the correspondence process is carried out. The current findings are compared with earlier results concerning 'optimality' of apparent motion to conclude that optimality cannot serve as a measure for the correspondence strength.

Penicillamine-induced polymyositis-dermatomyositis

Two patients with classical rheumatoid arthritis developed myopathy during treatment with penicillamine. In both patients, electromyography and muscle biopsies were indicative of polymyositis. In one patient, muscle enzymes were not examined at the appropriate time; in the other patient muscle enzymes were raised. This latter patient also had a rash and, in the dermal epidermal junction of pathological skin, granular deposits of immunoglobulin and complement were found. The myopathy subsided in both patients after withdrawal of penicillamine.