Rheumatoid cachexia: depletion of lean body mass in rheumatoid arthritis. Possible association with tumor necrosis factor

OBJECTIVE

To investigate body composition and serum tumor necrosis factor (TNF) levels in a series of 24 patients with rheumatoid arthritis (RA).

METHODS

Body composition assessment by anthropometric measures and bioelectrical impedance. Cytokine determination in serum by ELISA:

RESULTS

When compared to United States population norms, 16 of the subjects (67%) were cachectic. In regression models, lean body mass (LBM) was inversely associated with the number of swollen joints (p < 0.025). Elevated TNF-alpha was found in 3 of 5 flaring patients vs 0 of 18 patients with less active disease (p = 0.001). These 3 were all cachectic, while the 2 flaring patients without detectable TNF had normal LBM (p < 0.03). Among the whole group, there was a trend toward increasing disability with decreased LBM after adjusting for joint pain and disease duration (p < 0.07).

CONCLUSION

Cachexia is common in RA, and may be cytokine driven. Given the prognostic impact of LBM wasting in other diseases, the effect of rheumatoid cachexia on outcome in RA deserves further study.

Informational and neural adaptation curves are asynchronous

Norwich's entropy theory of perception (plus a few additional assumptions) suggests the existence of an "infromational adaptation curves" (change in stimulus equivocation with stimulus duration) for suprathreshold prothetic stimuli that is synchronous with the "neural adaptation curve" (change in firing rate with stimulus duration) observed for sensory neurons. Five experiments are reported in which informational adaptation curves were measured for auditory and visual stimuli by having subjects make absolute identifications of suprathreshold sound or light intenstiies of various durations. Information transmissions for the shortest duration stimuli (1 and 5 msec, respectively, for light and sound) were surprisingly large (small equivocations), indicating that intensity information is acquired very rapidly by the whole organism. The equations of entropy theory were fitted to adaptation data for peripheral sensory neurons (spiral ganglion cells and retinal ganglion cells) and were compared to the informational adaptation curves. It was found that informational adaptation occurred more rapidly than neural adaptation. That is, the two types of adaptation process are asynchronous. However, for both audition and vision, the total amount of information mediated by the adaptation process (channel capacity) was about the same for both types of processes (2.03 bits vs. 2.1 bits per stimulus for sound intensity; 1.3 vs. 2.0 bits per stimulus for light intensity). Faster acquisition could be accomplished in the whole organism through convergent neural circuits that increase sampling rate by pooling the samples taken by individual receptor systems.

Absence of human papilloma virus in cervical adenocarcinoma determined by in situ hybridisation

A few studies using DNA technology have suggested that human papillomavirus (HPV) may be an aetiological factor for adenocarcinoma of the uterine cervix. Twenty one cases of cervical adenocarcinoma were studied by in situ hybridisation using biotinylated DNA probes for HPV types 6, 11, 16 and 18 and a streptavidin, biotinylated alkaline phosphatase detection system. Intranuclear HPV DNA was detected in none of the adenocarcinomas, while positive controls gave a clear intranuclear signal. Adjacent areas of normal, koilocytic, and dysplastic squamous epithelium also gave positive results. It may be that squamous epithelium contaminates adenocarcinomas reported as positive by Southern blotting. Our results showing absence of detectable HPV DNA within adenocarcinomas suggest that HPV infection may not have a major role in the aetiology of adenocarcinoma of the uterine cervix.

Mixed-method mixed-modality psychophysical scaling

Four experiments are reported in which the direct psychophysical scaling methods of magnitude estimation, category judgment, and cross-modality matching were mixed in the same series of trials, both with a single stimulus modality and in a mixed-modality situation. The mixed-method scaling situation gave results consistent with those obtained when methods are used alone, and it has several advantages. Interactions between the methods were consistent with the idea that judgments made under all three are mediated by a primitive process of categorization that is influenced by heuristics used to achieve a single category identity for each stimulus.

Catabolic effects of high-dose corticosteroids persist despite therapeutic benefit in rheumatoid arthritis

Although corticosteroids (CS) cause nitrogen wasting in healthy humans, it is not known whether the salutary antiinflammatory and appetite-stimulating effects of CS in inflammatory diseases mitigate this effect. We measured nitrogen balance before, during, and after 3 d of high-dose methylprednisolone therapy in nine patients with flare-ups of rheumatoid arthritis. There was evidence of preexisting somatic protein and fat depletion in seven of nine subjects. Patients were allowed to eat freely on a metabolic ward. Nitrogen balances were -0.89 +/- 1.38 g/d (means +/- SEM) before CS therapy, -5.77 +/- 1.30 g/d during therapy (P less than 0.001), and -3.54 +/- 1.38 g/d after therapy (P less than 0.01) despite increased energy and nitrogen intake and clinical resolution of inflammation during and after the pulse therapy. We conclude that patients with rheumatoid arthritis are often cachectic and high-dose CS cause nitrogen wasting in these patients despite an antiinflammatory and appetite-stimulatory benefit.

Critical bands and mixed-frequency scaling: sequential dependencies, equal-loudness contours, and power function exponents

Stimuli of random intensities and various but predictable frequencies were presented for repeated magnitude estimations on the same scale (mixed-frequency scaling). The frequencies for a particular judgment session were selected so that they lay either inside each other's critical bands or outside them. Contrastive dependencies of current magnitude estimation responses on previous stimuli of a different frequency were significantly affected by whether the two frequencies were inside or outside each other's critical bands, while assimilative dependencies were not. This reinforces the idea that such dependencies are sensory in nature and arise from a different mechanism than do the assimilative dependencies. Mixed-frequency scaling of loudness also gives rise to cross-frequency matching functions from which equal-loudness contours can be calculated. These contours calculated from the present judgments are similar to those produced from other methods, even when they are extrapolated to untested intensities. Power function exponents for loudness scaled in this way are larger for lower frequencies, as has been found in previous studies, and are consistent with the flattening of the calculated equal-loudness contours for low frequencies as intensity increases.

Unmasking the magnitude estimation response

The fuzzy judgement model of Ward (1979) predicts an inverse relation between the amount of stimulus information available to subjects and the magnitude of sequential dependencies on previous stimuli and responses in psychophysical scaling tasks. Ward confirmed this prediction for magnitude estimations of interdot distance for previous responses but not for previous stimuli, although the inverse relation has been repeatedly reported for both the previous stimuli and responses in absolute identification (e.g., Mori, 1989). This paper further explores this seemingly puzzling contradiction. A magnitude estimation of loudness experiment was conducted in which the amount of stimulus information available to subjects was manipulated by a modified version of informational masking (Watson, 1987). An absolute-identification-with-feedback experiment was also conducted to check the effectiveness of the informational masking in reducing the amount of stimulus information. The results of the magnitude estimation experiment show a striking similarity with those of Ward and generalize the failure of sequential dependencies on previous stimuli to vary inversely with stimulus information. An additional assumption that judgement strategies are altered under low-information conditions is necessary to explain this result.

Cross-modal additive conjoint structures and psychophysical scale convergence

I investigated a variety of issues related to the measurement of the magnitude of psychological experience, especially the magnitude of sensations. Different groups of subjects made pair comparisons, magnitude estimations, and category judgments of the "total sensory magnitude" of light and sound stimuli presented conjointly. Another group judged the dissimilarity of pairs of conjoint stimuli. Various axioms, especially double cancellation, were tested on the resulting rank orders of conjoint stimuli. Judgements of the total magnitude of conjoint combinations of sound and light stimuli formed an additive conjoint structure. Dissimilarity judgments gave rise to a closely related lattice structure. Moreover, various scales of the individual attributes (loudness and brightness) calculated from the two types of judgments of the conjoint stimuli displayed substantial convergence, each scale for a given modality being linear with all other scales for that modality.

Remembrance of sounds past: memory and psychophysical scaling

What is the role of long-term memories of previous stimulus-response mappings, and of previous sensory and perceptual experiences generally, in psychophysical scaling judgments? I conducted four experiments in an attempt to provide some preliminary answers to this question. In each experiment, subjects made judgments of the loudness of sounds on 3 successive days. Stimulus intensities were drawn randomly from the same set on Days 1 and 3 but from a different set, either all 12 dB higher or all 12 dB lower, on Day 2. Four different types of psychophysical scaling judgments were studied: category judgment without an experimenter-induced identification function, ratio magnitude estimation with a variable standard, absolute magnitude estimation, and cross-modality matching. The first two methods required completely relative judgment, the last two completely absolute judgment. Data from all methods reveal profound effects of stimulus-response mappings experienced on previous days (long-term memory) and immediately previous stimuli and responses (short-term memory) on responses to current stimuli. Responses were typically a compromise between absolute and relative judgment. Individual differences were dramatic.

Remembrance of sounds past: Memory and psychophysical scaling

What is the role of long-term memories of previous stimulus-response mappings, and of previous sensory and perceptual experiences generally, in psychophysical scaling judgments? I conducted four experiments in an attempt to provide some preliminary answers to this question. In each experiment, subjects made judgments of the loudness of sounds on 3 successive days. Stimulus intensities were drawn randomly from the same set on Days 1 and 3 but from a different set, either all 12 dB higher or all 12 dB lower, on Day 2. Four different types of psychophysical scaling judgments were studied: category judgment without an experimenter-induced identification function, ratio magnitude estimation with a variable standard, absolute magnitude estimation, and cross-modality matching. The first two methods required completely relative judgment, the last two completely absolute judgment. Data from all methods reveal profound effects of stimulus-response mappings experienced on previous days (long-term memory) and immediately previous stimuli and responses (short-term memory) on responses to current stimuli. Responses were typically a compromise between absolute and relative judgment. Individual differences were dramatic.

On evolutionary systems

This paper develops a metatheoretical framework for understanding evolutionary systems (systems that develop in ways that increase their own variety). The framework addresses shortcomings seen in other popular systems theories. It concerns both living and nonliving systems, and proposes a metahierarchy of hierarchical systems. Thus, it potentially addresses systems at all descriptive levels. We restrict our definition of system to that of a core system whose parts have a different ontological status than the system, and characterize the core system in terms of five global properties: minimal length interval, minimal time interval, system cycle, total receptive capacity, and system potential. We propose two principles through the interaction of which evolutionary systems develop. The Principle of Combinatorial Expansion describes how a core system realizes its developmental potential through a process of progressive differentiation of the single primal state up to a limit stage. The Principle of Generative Condensation describes how the components of the last stage of combinatorial expansion condense and become the environment for and components of new, enriched systems. The early evolution of the Universe after the "big bang" is discussed in light of these ideas as an example of the application of the framework.

Antiphospholipid antibodies associated with retinal vascular disease

Two patients with retinal vascular disease also had antiphospholipid antibodies, defined by the presence of the circulating lupus anticoagulant (LAC), anticardiolipin antibodies, or both. One had retinal arterial occlusions and the other had a nonischemic central retinal vein occlusion. The association of thrombotic vascular disease, including both retinal and cerebral vessels, with the presence of these antibodies should be investigated in otherwise normal individuals or in patients presenting with a lupuslike syndrome and retinal vascular occlusive disease. Low-dose aspirin administration could be of therapeutic value in managing thrombotic events in this group of patients.

The relationship between articulation disorders and motor coordination in children

This study was designed to examine the relationship between articulation disorders, soft neurological signs, and motor abilities. Fifteen children with articulation problems, as measured by the Templin-Darley Articulation Screening Test and a connected speech sample, were compared with a normal control group (matched for sex and age) on the Quick Neurological Screening Test, the Imitation of Postures test (from the Southern California Sensory Integration Tests), and the 1984 version of the Stott Test of Motor Impairment that has been revised by Henderson. A significant difference was found between the groups on the Motor Impairment Test and the Quick Neurological Screening Test, supporting the hypothesis that the articulation disorder children would have more motor coordination problems and soft neurological signs than the normal children in the control group. There was no between-group difference on the Imitation of Postures test, suggesting that as a group, children with articulation deficits are not dyspraxic. This study supports other research findings stating a relationship between articulation problems and motor impairment, but it also indicates that this motor impairment is not necessarily dyspraxia.

Determinants of attention to local and global features of visual forms

This article deals with the problem of how attention is distributed to different levels of detail (global, local) in visual scenes. Six experiments explore the effect of a previous level of processing on current processing. The contention that processing at a given level of detail biases the distribution of attention so that more is allocated to that level for future processing is supported by the presence in the data of a robust level-readiness effect, whereby processing is faster at a given level if previous processing has been at that level. The level-readiness effect occurs regardless of the conspicuity of features at the various levels. Conflict between levels seems to depend on the imbalance of conspicuity and attention allocation between levels, with the more conspicuous or attended-to-level interfering more. A model of two-state attention switching similar to that of Sperling and Melchnor (1978) is proposed to explain these data. the final experiment confirmed the somewhat unusual prediction of this model that sometimes processing under focusing-attention conditions can be slower than that under divided-attention conditions.

Determinants of attention to local and global features of visual forms

This article deals with the problem of how attention is distributed to different levels of detail (global, local) in visual scenes. Six experiments explore the effect of a previous level of processing on current processing. The contention that processing at a given level of detail biases the distribution of attention so that more is allocated to that level for future processing is supported by the presence in the data of a robust level-readiness effect, whereby processing is faster at a given level if previous processing has been at that level. The level-readiness effect occurs regardless of the conspicuity of features at the various levels. Conflict between levels seems to depend on the imbalance of conspicuity and attention allocation between levels, with the more conspicuous or attended-to-level interfering more. A model of two-state attention switching similar to that of Sperling and Melchnor (1978) is proposed to explain these data. the final experiment confirmed the somewhat unusual prediction of this model that sometimes processing under focusing-attention conditions can be slower than that under divided-attention conditions.

Stimulus information and sequential dependencies in magnitude estimation and cross-modality matching

Descriptive models of magnitude estimation and cross-modality matching derived from two different approaches to psychophysical judgment, the response ratio hypothesis and the fuzzy judgment approach, are compared. The two approaches emphasize different bodies of facts but both attempt to account for sequential dependencies in psychophysical judgments. Both models suggest a hierarchical multiple linear regression model for such data. Some of the predictions of the models are explored in the context of two experiments in which the amount of stimulus information available to subjects in magnitude estimation and cross-modality matching tasks is varied. The fuzzy judgment approach generally does better in explaining the form of such data.

Levels of processing in visual illusions: the combination and interaction of distortion-producing mechanisms

In order to assess the mode and sequence of interaction of visual-geometric illusion mechanisms, responses to simple and composite overestimation configurations were measured in 72 observers. Analysis suggests that some illusion mechanisms add their distortions to the outputs of others and that other mechanisms average. A logarithmic or near-logarithmic transformation seems to occur when illusory effects combine. A path analysis of the results suggests that some illusory mechanisms combine in a serial manner and that others operate on separate parallel channels. Notions based on simple addition of illusory effects and on serial linear processing are not supported by these analyses.

Levels of processing in visual illusions: The combination and interaction of distortion-producing mechanisms

In order to assess the mode and sequence of interaction of visual-geometric illusion mechanisms, responses to simple and composite overestimation configurations were measured in 72 observers. Analysis suggests that some illusion mechanisms add their distortions to the outputs of others and that other mechanisms average. A logarithmic or near-logarithmic transformation seems to occur when illusory effects combine. A path analysis of the results suggests that some illusory mechanisms combine in a serial manner and that others operate on separate parallel channels. Notions based on simple addition of illusory effects and on serial linear processing are not supported by these analyses.

Stimulus information and sequential dependencies in magnitude estimation and cross-modality matching

Descriptive models of magnitude estimation and cross-modality matching derived from two different approaches to psychophysical judgment, the response ratio hypothesis and the fuzzy judgment approach, are compared. The two approaches emphasize different bodies of facts but both attempt to account for sequential dependencies in psychophysical judgments. Both models suggest a hierarchical multiple linear regression model for such data. Some of the predictions of the models are explored in the context of two experiments in which the amount of stimulus information available to subjects in magnitude estimation and cross-modality matching tasks is varied. The fuzzy judgment approach generally does better in explaining the form of such data.

The case for misapplied constancy scaling: depth associations elicited by illusion configurations

It has been suggested that many visual-geometric illusions arise from inappropriate evocation of size-constancy by depth cues implicit in illusion configurations. Observers gave free association responses while viewing illusion figures. Analysis of these responses provides weak but consistent evidence for the elicitation of depth in the Sander parallelogram, Mueller-Lyer, Zoellner, and Ehrenfels variant of the Ponzo illusion. No evidence for depth is found in the normal form of the Ponzo, Poggendorff, and horizontal-vertical illusions, and the evidence is ambiguous in the Orbison configurations. These results indicate that depth processing may be evoked by some, but not all, classical illusion forms.

Multidimensional Scaling Of The Molar Physical Environment

Two experiments were carried out in order to make tests of several hypotheses concerning perceptions of the molar physical environment. In the first, subjects did multiple category sorts of pictures of environments from three different functional orientations (what is done in or to the environment). In the second, subjects made similarity judgments of all pairs of the same pictures. Data from both experiments were analyzed by INDSCAL and MDSCAL and the resulting multidimensional stimulus spaces compared across conditions, experiments, and analysis methods. It was found that as functional orientations change (Expt. I), stimulus structures and dimensional interpretations of those structures remain invariant, while individual saliences of those dimensions change. Dimensions of naturalness and scale predominated in both experiments, and dimensional and stimulus structures were highly similar across judgment methods. INDSCAL and MDSCAL solutions were highly similar, but INDSCAL solutions were easier to interpret without rotation, while MDSCAL tended to extract fewer dimensions and to fit better with the original data. In the second experiment dimensional saliences were related to subjects' background characteristics and clusters of subjects were characterized according to differences in dimensional saliences.

Levels of feature analysis in processing visual patterns

In this paper, a revised Pandemonium-like model of visual-feature processing is formulated and a preliminary test of its feasibility is reported. The model differentiates visual-feature processing into a series of hierarchical stages organized by increasing complexity, with the output of each stage going both to the next higher stage, and directly to a more central processor. In the experiment, subjects sorted decks of cards into piles according to the presence or absence of a target stimulus which differed from nontargets in a variety of different features; detection of a feature was sufficient for detection of a target. The data generally supported the revised Pandemonium model, in that targets which differed from nontargets in features thought to be low in the hierarchy were processed faster than targets whose difference was in a high level feature. An extension of the revised model did somewhat less well in predicting the results of sorting for targets in which detection of any one of several features was sufficient for target detection.

On the internal consistency of magnitude estimations

The data from experiments in magnitude estimation of discomfort glare and loudness are reported. A distribution of stimuli and judgments was used which allowed a check for the internal consistency of the magnitude estimations. An interval interpretation of the resulting scales for glare and loudness was found to be more compatible with the consistency checks than was a ratio interpretation. The interval scales were nicely fit by power functions of the form R = aSn + b. The scale for glare represents a first approximation to a usable scale for discomfort glare different from the typical brightness scale.

The field distribution of strains of nodule bacteria from species of Medicago

Tests of nodulation and ability to fix nitrogen, together with serological reactions, are reported for localized isolates from Medicago hispida var. denticulata and M. laciniata. For a particular host species strains were distributed randomly within the area investigated, except that a particular somatic antigen found among M. laciniata isolates was limited to one locality. In reciprocal tests between isolates from these two hosts, nodulation has been mainly confined to the homologous host. Although some strains fail in laboratory tests to nodulate the homologous host and although separation into two groups is not complete, there are relatively few cases of discrepancy and many of these show intermediate characteristics. Medicago sativa and Melilotus alba are generally readily nodulated by isolates from both field hosts. The nodulation differences between strains from the two field hosts are paralleled to some extent by serological properties, but it is suggested that this correlation shows recent common origin of similar strains rather than any fundamental relationship between invasibility and antigenic constitution. Effective association was seldom, if at all, achieved with M. laciniata, whereas with other testing hosts effective responses were in the majority and even included a number of isolates originating from M. laciniata and ineffective with that species as host.