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PubMed1988

[A study of DNA ploidy patterns of gastric cancers].

The nuclear DNA fluorescence of gastric cancer cells which were obtained from endoscopic biopsies and paraffin block specimen was measured. Histograms in 142 cases could be roughly classified into four types: Type Ia, means diploid pattern without polyploid cells, type Ib, diploid pattern with polyploid cells, type II, heteroploid pattern and type III, mosaic pattern. Although these DNA patterns showed no correlation with histological types, type Ia was frequently found in early-stage cancer and type III in advanced-stage cancer. In cases without vascular invasion and in each metastasis, type Ia were significantly numerous. With regard to prognosis, the survival rate was becoming poorer in order of Ia less than Ib less than II less than III. In 41 cases out of 45 advanced-stage cancers, DNA patterns of superficial and deep portion of gastric cancer were found the same. In 5 cases, DNA patterns of cancer cells in metastatic lymph nodes were coincident with DNA patterns in gastric cancers. These results suggested that the measurement of nuclear DNA pattern may provides a biological activity of gastric cancer cells and preoperative examination of endoscopic biopsy specimens from this aspect is also clinically important.

Adenocarcinoma↗
PubMed1986

The significance of double phenotypic patterns and markers in human sarcomas. A new model of mesenchymal differentiation.

Six soft-tissue sarcomas with two separate and juxtaposed histologic patterns were selected for immunohistochemical analysis. The first pattern was represented by five phenotypes (schwannian-skeletal muscle [Triton], cartilagenous, synovial, adipocytic, and smooth muscle). In each case the second histologic pattern resembled the fibrohistiocytic phenotype, ie, malignant fibrous histiocytoma (MFH). No other histologic patterns were identified. Appropriate cell markers were demonstrated in each of the first patterns; these were not detected in the second patterns. In contrast, the second pattern in all cases expressed alpha 1-antichymotrypsin, a marker commonly found in fibrohistiocytic lesions; this was not identified in any of the first patterns. This loss of one cell-specific marker and gain of another is termed the "antigenic shift" phenomenon and appeared to foretell the emergence of a true second phenotype (the same in each of these cases, which could be termed "dedifferentiated" sarcomas). Therefore, it is hypothesized that MFH is a final common pathway for some types of sarcomas and is the result of tumor progression or "dedifferentiation." The practical implications of this hypothesis concern the approach to sarcoma differential diagnosis and the meaning of an MFH pattern in both metastatic and primary sites. On a theoretic level, this hypothesis and the antigenic shift phenomenon force a reconsideration of the pathways of soft-tissue differentiation. A new model of mesenchymal differentiation incorporating these concepts is described and supported. It provides an explanation for a number of facts in soft-tissue pathology, and its predictions can be tested.

Aged↗
PubMed1987

Neural control of limb coordination. I. Comparison of hatching and walking motor output patterns in normal and deafferented chicks.

Previous work has shown that the neural circuits underlying the leg movements of walking and hatching coexist in post-hatching chicks (Bekoff and Kauer, 1984). In the present study, quantitative analysis of leg EMGs shows that there are some similarities, but also significant differences, in the motor output patterns of walking and hatching. This study examines the effect of removing sensory feedback from the legs on the production of the distinctive leg motor patterns. The temporal characteristics and interlimb coordination of hatching and walking are little affected. However, major changes in intralimb motor output patterns are seen when compared to records from normal chicks. These changes fall into one of 2 categories. Some parameters show similar changes in both behaviors after deafferentation (e.g., increases in flexor burst durations and cycle period). This suggests that certain features of sensory input from the legs normally modulate the hatching and walking pattern-generating circuitry in similar ways. Other parameters show convergence. That is, these aspects of the 2 intralimb motor patterns become more similar to each other after removal of sensory input. This is consistent with the hypothesis that some feature of sensory input from the legs normally modulates one set of multiuse intralimb circuitry to produce different output patterns. In general, the walking pattern becomes more like hatching after deafferentation, rather than the reverse, which suggests that the hatching pattern is a more basic one. The maintenance of some residual differences in intralimb motor patterns after leg deafferentation suggests that other sources of modulation must also be involved, or that there are some additional elements of circuitry that are called into play during the normal production of walking and hatching.

Animals↗
PubMed1977

[Spike discharges on stimulation with diffuse and patterned light in epileptic and non-epileptic patients (author's transl)].

The effects of photic stimulation with intermittent diffuse light and patterned flash were compared in 587 patients. The diagnosis of epilepsy was unquestionable in 216 patients and suspected in 150 cases while 221 patients had no evidence of epileptic attacks. None of these patients had a history of photosensitive epilepsy. A grid pattern with squares subtending 22' of arc was used in the first 28 patients while the following 379 patients were tested with a checkerboard pattern of corresponding size. In 51 cases generalized spikes or spike-waves and/or occipital spikes were obtained. These discharges were elicited by diffuse light as well as by patterned flash in 37 patients. 11 cases were insensitive to pattern. In 3 cases spike discharges were seen only with patterned light while diffuse light was without effect. The response consisted in 13 cases of generalized spikes and spike-waves. 12 of these had an unquestionable epilepsy. Occipital spikes only were seen in 38 patients; 22 of these suffered from epilepsy. Patterned light was in no case found to be more effective than diffuse light for eliciting generalized epileptic discharges. In the 3 cases where only patterned light produced spikes, these were restricted to occipital regions. As occipital spikes do not have the same significance for the diagnosis of epilepsy as generalized spikes the addition of patterned flash to diffuse light stimulation does not seem to be of great value.

Adolescent↗
PubMed1984

Colour pattern modification by coldshock in Lepidoptera.

When young pupae of Vanessa cardui, V. virginiensis and Precis coenia (Lepidoptera: Nymphalidae) are exposed to severe coldshock many develop aberrant adult wing patterns. For each species, a synchronous cohort of experimental animals always develops a broad range of aberrant pattern morphologies but these can always be arranged in a single unbranched morphological series. When such phenotypic series are compared, between species and between wing surfaces within a species (each wing surface usually bears a different colour pattern), many parallel modifications and trends become evident. These parallelisms reveal certain homologies of pattern elements and suggest that a common physiology underlies the development of a considerable diversity of normal and aberrant colour patterns. The case is made that the phenotypic series produced may represent either a series of sequential stages in colour pattern determination or, a series of quantitatively different 'interpretations' of an established gradient system. Colour pattern morphoclines reveal which patterns are developmentally 'adjacent' to one another and may therefore prove useful in elucidating the evolution of patterns.

Animals↗
PubMed1984

Butterfly wing patterns: how good a determining mechanism is the simple diffusion of a single morphogen?

The formation of the wing pigmentation patterns of three species of butterflies has been modelled using a mechanism based on a tripod of assumptions. First, that there may be morphogen sources in the foci of eyespots and morphogen sinks at some parts of the wing margin, all other cells being passive. Second, that the morphogen has a finite half life and diffuses simply and freely away from the sources throughout a wing of hexagonally packed cells. Third, that the overt pattern derives from cells interpreting the local morphogen concentration with respect to thresholds which determine scale colours. The final pattern thus follows lines of constant morphogen concentration and may, depending on the distribution of sources, comprise rings, curves or bands. With such a model, we have been able to compute stable patterns having the essential topology of the compound spots of Tenaris domitilla, the large rings of Diaethria marchalii and the pattern of eyespots, rings and asymmetric bands of Ragadia minoa. Quantitative analysis of the pattern-forming process shows that, with a biologically realistic diffusion constant (approximately 5.10(-7) cm2 sec-1) and a morphogen half life less than 6h, the patterns form within approximately 12h over a wing of approximately 1000 cells in length. The limitations of the model are that the exact morphology of the eyespots and bands do not match precisely those of the original wings, that there are edge distortions and that optimal patterns may be critically dependent on the exact positions of sources and sinks. An explanation for part of the discrepancy is that we have assumed an adult wing shape and foci coordinates in modelling a process that took place earlier in development. Nevertheless, the limitations of the model argue against a mechanism based on a single morphogen operating in vivo. However, as the model can generate many features of butterfly wing patterns, it may be considered as a degenerate case of that mechanism.

Animals↗
PubMed1995

Sensitivity to violations of "run" and "trill" structures in rat serial-pattern learning.

Rats learned serial patterns composed of either "run" chunks (e.g., 123 234 ...) or "trill" chunks (e.g., 121 232 ...). For each type of pattern, 1 group of rats encountered an element at the end of the pattern that violated the run or trill structure. In both run and trill patterns, violations were unusually difficult for rats to learn, whereas corresponding elements in "perfect" patterns that did not violate pattern structure were easy. Additionally, rats' errors on violation elements conformed to the structure of the patterns in which they were embedded. Thus, rats were sensitive to the run or trill organization of their patterns and mastered the rules governing the pattern before learning "exceptions to the rule."

Animals↗
PubMed1994

Pattern interpretation by cellular automata (PICA)--evaluation of tumour cell adhesion in human melanomas.

In routine pathology, the evaluation of the pattern of a tumour at scanning magnification often reveals diagnostic and prognostic features indicating that the biological properties of the tumour cells are related to the morphological pattern. For further evaluation of the relationship between functional properties of the cells on the one hand and the pattern on the other, we propose the pattern interpretation by cellular automata (PICA) procedure. The PICA system consists of an import module transferring real histological images into the data structure of a cellular automaton, a measurement module generating a comparable quantitative description of real and simulated images, a cellular automation designed to simulate tumour growth and invasion at the histological level, a database consisting of the morphological results obtained in simulated patterns, an interpretation module linking real histological images to the knowledge stored in the database and an image synthesis and display module. By comparing real images to computer-simulated patterns, PICA facilitates an estimation of functional properties based on the static histological pattern of a given tumour. Using the example of tumour cell adhesion, it is demonstrated that the degrees of tumour-tumour and tumour-stroma adhesion significantly affect the resulting simulated patterns, that, in turn, the morphological evaluation of the patterns enables a reproducible estimation of adhesion and that estimates of adhesion in real images of malignant melanoma of the skin are of prognostic significance. PICA may serve as an additional in situ evaluation technique linking morphological features to functional properties.

Cell Adhesion↗
PubMed1995

Mammalian enamel prism patterns and enamel deposition rates.

Enamel prism patterns and enamel deposition rates were compared for specimens representing six mammalian orders. Enamel samples were characterized by either pattern 1 or pattern 3 prisms. Each prism pattern category contained prisms from at least two mammalian orders. Enamel deposition rate was estimated for each sample by measuring prism cross striation repeat intervals. Statistical analysis of cross striation repeat intervals illustrates significant differences in deposition rate between prism patterns 1 and 3. No statistically significant differences were found in deposition rate between the higher-level taxa represented within each prism pattern category. That enamel deposition rate is not taxonspecific reinforces the close association between deposition rate and prism morphology. In accord with previous studies, pattern 1 enamel is deposited more slowly than is pattern 3 enamel. Correlation analyses illustrated a lack of association between enamel deposition rate and body mass, tooth size, and estimated ameloblast size. Evidence that enamel deposition rate is associated with enamel prism morphology, coupled with evidence that deposition rate is not correlated with size parameters, points to developmental homology (i.e., homogeneous deposition rate) within each prism pattern.

Animals↗
PubMedDate not supplied

Communication patterns of primary care physicians.

OBJECTIVES: To use audiotape analysis to describe communication patterns in primary care, to relate these to ideal relationship types as described in the literature, and to explore the patterns' relationships with physician and patient characteristics and satisfaction. DESIGN: Description of routine communication in primary care based on audiotape analysis and patient and physician exit questionnaires. SETTING: A total of 11 ambulatory clinics and private practices. PARTICIPANTS: The participants were 127 physicians and 537 patients coping with ongoing problems related to disease. MAIN OUTCOMES MEASURES: Roter Interactional Analysis System (RIAS) and patient and physician exit satisfaction questionnaires. RESULTS: Cluster analysis revealed 5 distinct communication patterns: (1) "narrowly biomedical," characterized by closed-ended medical questions and biomedical talk occurring in 32% of visits; (2) "expanded biomedical," like the restricted pattern but with moderate levels of psychosocial discussion occurring in 33% of the visits; (3) "biopsychosocial," reflecting a balance of psychosocial and biomedical topics (20% of the visits); (4) "psychosocial," characterized by psychosocial exchange (8% of visits); and (5) "consumerist," characterized primarily by patient questions and physician information giving (8% of visits). Biomedically focused visits were used more often with more sick, older, and lower income patients by younger, male physicians. Physician satisfaction was lowest in the narrowly biomedical pattern and highest in the consumerist pattern, while patient satisfaction was highest in the psychosocial pattern. CONCLUSIONS: Primary care communication patterns range from narrowly biomedical to consumerist patterns and parallel the ideal forms of patient-physician relationships described in the literature.

Analysis of Variance↗
PubMed1997

Retinal patterning in the zebrafish mutant cyclops.

Determination of cell fate in the vertebrate retina has been shown to be largely independent of lineage. After cell fates are determined, retinal neurons become organized in a precise laminar pattern. The mechanisms for this patterning could involve morphogens distributed in gradients or, alternatively, direct cell-cell interactions. In the zebrafish mutant cyclops (Cyc(b16)), most embryos have two partial retinas joined in the ventral midline. This presents developing retinal cells near the midline with abnormal cellular environments, whereas laterally the pattern of developing cells is normal. We examined the consequences of this for patterning in the mutant's retina. We found that the retinas are joined in the midline at the apical surfaces of the photoreceptor layers. A laminar pattern emerges in the midline that preserves normal positional relationships between retinal cell types locally but is abnormal with respect to patterning over the entire retina. Lateral to the midline, retinal patterning appears normal. Metabolic labeling experiments showed that late rounds of DNA synthesis precede the emergence of the novel pattern in this midline region. We conclude that these observations in the cyclops mutant are compatible with mechanisms of pattern formation in the retina involving local cell interactions.

Animals↗
PubMed1997

Contingent-dependent enhancement of rhythmic motor patterns: an in vitro analog of operant conditioning.

Operant conditioning is characterized by the contingent reinforcement of a designated behavior. Previously, feeding behavior in Aplysia has been demonstrated to be modified by operant conditioning, and a neural pathway (esophageal nerve; E n.) that mediates some aspects of reinforcement has been identified. As a first step toward a cellular analysis of operant conditioning, we developed an in vitro buccal ganglia preparation that expressed the essential features of operant conditioning. Motor patterns that represented at least two different aspects of fictive feeding (i.e., ingestion-like and rejection-like motor patterns) were elicited by tonic stimulation of a peripheral buccal nerve (n.2,3). Three groups of preparations were examined. In a contingent-reinforcement group, stimulation of E n. was contingent on the expression of a specific type of motor pattern (i.e., either ingestion-like or rejection-like). In a yoke-control group, stimulation of E n. was not contingent on any specific pattern. In a control group, E n. was not stimulated. The frequency of the reinforced pattern increased significantly only in the contingent-reinforcement group. No changes were observed in nonreinforced patterns or in the motor patterns of the control and yoke-control groups. Contingent reinforcement of the ingestion-like pattern was associated with an enhancement of activity in motor neuron B8, and this enhancement was specific to the reinforced pattern. These results suggest that the isolated buccal ganglia expressed an essential feature of operant conditioning (i.e., contingent reinforcement modified a designated operant) and that this analog of operant conditioning is accessible to cellular analysis.

Action Potentials↗
PubMedDate not supplied

The effects of patterned breathing and continuous positive airway pressure on cardiovascular regulation in healthy volunteers.

1. Although the increased heart rate variability in healthy subjects in association with slow patterned breathing and continuous positive airway pressure is well documented, there is no general agreement regarding the underlying mechanism. The arterial baroreceptor stimulation due to greater blood pressure variability, the stimulation of pulmonary stretch and low pressure baroreceptors can play important role in this phenomenon. 2. In order to assess the interplay between blood pressure and heart rate changes we have studied nine healthy volunteers (mean age was 22 yrs. range 19-24), by applying 6/min patterned breathing, and continuous positive airway pressure of 10 cm of water. ECG and finger blood pressure (Finapres 2300) was continuously recorded. The oscillation amplitude of R-R intervals were analysed as well as the time and frequency domain indexes of heart rate variability. The oscillation amplitude and the corresponding frequency domain components of systolic blood pressure were also calculated. 3. The forced deep breathing caused significant increase in heart rate variability as indicated by time and frequency domain analysis of R-R intervals (LF HRV ms2: spontaneous: 777.40 +/- 526.1, patterned breathing 6828.00 +/- 5468.0). The application of CPAP in the same rhythm during patterned breathing resulted in further enhancement in heart rate variability (LF HRV ms2: 9052.00 +/- 4533.0). The analysis of the same frequency domain components of systolic blood pressure showed marked elevation of the total and low frequency power during patterned breathing. (LF BPV mm Hg2: spontaneous: 8.24 +/- 6.2, patterned breathing: 16.22 +/- 9.7). Applying CPAP with the same breathing pattern elicited further significant increment in systolic blood pressure fluctuation (LF BPV mm Hg2: deep breathing + CPAP: 27.11 +/- 9.8). The baroreflex sensitivity as calculated from spontaneous HR and BP sequences was 11.66 +/- 2.9 at baseline and increased to 17.66 +/- 6.1 and changed to 15.22 +/- 3.2 with the addition of patterned breathing and CPAP, respectively. 4. Our findings indicate that the heart rate and blood pressure responses to slow patterned breathing may be interpreted as consequences of an altered baroreflex sensitivity. In contrast the active breathing with CPAP exerts mechanical effects which in turn present an augmented systemic baroreflex trigger, however, the baroreflex sensitivity remains unchanged.

Adult↗
PubMed1997

Structure and spatial pattern of the sensilla of the body segments of insect larvae.

We describe the types and patterns of sensilla present on the thorax and abdomen of newly hatched larvae of representative species of several insect orders, among them Saltatoria, Mantodea, Blattaria, Heteroptera, Lepidoptera, and Diptera. Sensilla of non-Dipteran species almost exclusively comprise mechanoreceptive hairs or bristles (trichoid sensilla) of various sizes and numbers. In higher Dipterans, peg sensilla (sensilla basiconica, sensilla coeloconica) and so-called papilla sensilla predominate. The pattern of early larval sensilla falls into three main classes, which can be described as 1) fixed pattern, 2) variable pattern, and 3) variable pattern with fixed elements. In larvae exhibiting a fixed sensillum pattern (found in all Dipteran species investigated), sensilla are invariant in number; they are precisely placed in relationship to each other and typically form a single row behind the middle of each segment. A variable pattern (common in most insect groups) typically consists of several rows of relatively evenly spaced sensilla encircling the middle of each segment. In animals with a variable pattern including fixed elements, some sensilla, recognizable by their size or shape, are precisely placed, whereas other sensilla surrounding them are variable.

Animals↗
PubMed1990

Automatically inferred Markov network models for classification of chromosomal band pattern structures.

A structural pattern recognition approach to the analysis and classification of metaphase chromosome band patterns is presented. An operational method of representing band pattern profiles as sharp edged idealized profiles is outlined. These profiles are nonlinearly scaled to a few, but fixed number of "density" levels. Previous experience has shown that profiles of six levels are appropriate and that the differences between successive bands in these profiles are suitable for classification. String representations, which focuses on the sequences of transitions between local band pattern levels, are derived from such "difference profiles." A method of syntactic analysis of the band transition sequences by dynamic programming for optimal (maximal probability) string-to-network alignments is described. It develops automatic data-driven inference of band pattern models (Markov networks) per class, and uses these models for classification. The method does not use centromere information, but assumes the p-q-orientation of the band pattern profiles to be known a priori. It is experimentally established that the method can build Markov network models, which, when used for classification, show a recognition rate of about 92% on test data. The experiments used 200 samples (chromosome profiles) for each of the 22 autosome chromosome types and are designed to also investigate various classifier design problems. It is found that the use of a priori knowledge of Denver Group assignment only improved classification by 1 or 2%. A scheme for typewise normalization of the class relationship measures prove useful, partly through improvements on average results and partly through a more evenly distributed error pattern. The choice of reference of the p-q-orientation of the band patterns is found to be unimportant, and results of timing of the execution time of the analysis show that recent and efficient implementations can process one cell in less than 1 min on current standard hardware. A measure of divergence between data sets and Markov network models is shown to provide usable estimates of experimental classification performance.

Chromosome Banding↗
PubMed1987

The pattern ERG in response to colored stimuli.

The pattern-evoked electroretinogram (PERG) was studied in response to square-wave stripe patterns contrasting either between dark and colored stripes ("red-black" or "green-black" luminance contrast pattern) or between the two colors (red-green chromatic contrast pattern). All lights were matched in photopic luminance. A two-channel Maxwellian view system was used to present the stimuli in the onset-offset mode. When no pattern was present a mixture of both colors was seen. Different spatial frequencies were studied and the amplitudes of the onset response were evaluated. When the two luminance contrast patterns were presented, the responses showed a spatial selectivity. However the combination of the two colors (red-green contrast) resulted in a monotonic decrease of the response with spatial frequency. The spatially selective behavior of the response to luminance contrast patterns could be associated with the on-off center-surround organization of retinal receptive fields. The behavior of the response to chromatic-contrast patterns, on the other hand, could be explained by the action of color-opponent center-surround receptive fields as described in the primate.

Color Perception↗
PubMed1994

Influence of simultaneous pattern-reversal electroretinogram recording on visual evoked potentials.

Little is known about the influence of the presence of a gold-foil electrode on pattern-reversal visual evoked potential recording, although simultaneous pattern-reversal electroretinography has been applied in several clinical investigations. We compared the results of pattern-reversal visual evoked potentials simultaneously recorded with pattern-reversal electroretinograms with those obtained during separate pattern-reversal visual evoked potential recording in 10 normal subjects. Transient response (reversal rate, 1 Hz; check size, 30') and steady-state response (reversal rate, 5 Hz; check size, 120', 60', 30', 15' and 7.5') were analyzed under the stimulus contrast condition of 90%. Neither P100 latency in transient responses nor amplitudes in steady-state responses exhibited significant change at any check size when they were recorded separately or simultaneously with pattern-reversal electroretinograms. The results suggest that the gold-foil electrode exerts no significant influence on pattern-reversal visual evoked potentials. Simultaneous pattern-reversal electroretinogram and visual evoked potential recording is therefore confirmed to be a clinically useful method. This procedure makes the synchronous recording of both responses possible under the identical stimulus conditions.

Adult↗
PubMedDate not supplied

The effect of motion on pattern-onset visual evoked potentials in adults and children.

Visual evoked potentials can be elicited by a variety of visual stimuli, including pattern-onset and motion-onset. It may be desirable to combine pattern-onset with motion-onset stimuli, for example, to make a direct comparison between optokinetic nystagmus and visual evoked potential acuity thresholds. Both procedures employ grating stimuli; however, the gratings must be moving to produce optokinetic nystagmus. We compared pattern-onset visual evoked potentials with both a static and a moving pattern to investigate the effect of motion on the pattern-onset visual evoked potential waveform. Visual evoked potential recordings were made from 10 adults (aged 20-37 years) and 10 children (aged 5-7 years) with the active electrode at Oz. Stimuli consisted of onset of high-contrast vertical bars of three sizes (12', 30' and 60') both with and without motion (3 cycles/s). In a subgroup of subjects, visual evoked potentials were recorded to motion onset of constantly present gratings. Motion of the pattern had no significant effect on any of the latency components of the visual evoked potential waveform in adults or children. The amplitude of the C2-C3 component was significantly increased (p < 0.001) in adults. The motion appears to add a late negative component to the visual evoked potential similar to that produced by the motion-only stimulus. The latency of the early components of the pattern-onset visual evoked potential was unaffected by the presence of motion. Therefore, pattern-onset visual evoked potentials with moving gratings could be used to estimate visual acuity, and direct comparisons could be made between visual evoked potential and optokinetic nystagmus acuity thresholds with the use of the same stimulus parameters.

Adult↗