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PubMed1995

Motion detection in interleaved random dot patterns: evidence for a rectifying nonlinearity preceding motion analysis.

Three experiments examined direction discrimination in temporally interleaved random dot patterns. The stimulus consisted of two or more uncorrelated random patterns presented in a repeating temporal sequence, so that each pattern appeared only once every n frames, separated by uncorrelated patterns. Each pattern shifted either leftward or rightward at each re-appearance (all patterns shifted in the same direction in any one presentation). Subjects could specify shift direction correctly even when eight different patterns were interleaved, provided that the duration of each frame was brief. An explanation based on responses in first-order motion energy detectors tuned to low spatiotemporal frequencies (effectively summating the interleaved patterns over time) was tested using a stimulus in which each pattern inverted in contrast mid-way through each frame. Contrary to predictions based on temporal summation, performance with contrast-inverting patterns was only slightly lower than with non-inverting patterns. An alternative explanation was examined, based on responses in motion detectors that full-wave rectify image contrast before extracting motion energy. Computed responses from such detectors successfully predicted psychophysical performance with interleaved random patterns. Implications for models of motion analysis are discussed.

Discrimination, Psychological↗
PubMed1997

Responsiveness of neurons in the posterior inferotemporal cortex to visual patterns in the macaque monkey.

Using anesthetized and immobilized monkeys, responses of neurons in the posterior inferotemporal cortex to visual patterns were examined. Response properties were compared between the sulcus and the gyrus, extending between the anterior tip of the posterior middle temporal sulcus and the inferior occipital sulcus. Of 682 neurons tested, 37% in the sulcus (134/365) and 36% in the gyrus (113/317) responded to one or more patterns. The preference of neurons for patterns varied from neuron to neuron; some neurons responded selectively to one particular pattern, whereas others responded to two or more patterns. To evaluate response properties of neurons, two indices were calculated (the pattern preference index and the pattern selectivity index). The distributions of these indices in the sulcus did not differ significantly from those of the gyrus. Furthermore, the relationship between the pattern preference index and the pattern selectivity index for each neuron was almost the same in these two portions; most neurons responding to a small number of patterns showed inhibitory or weak responses to the worst pattern. In both portions, most neurons had receptive fields with small eccentricities and receptive field sizes were almost the same. These results suggest that the cortex in the sulcus in the posterior inferotemporal cortex is involved in the detection of features of visual patterns, similarly to the cortex in the gyrus.

Animals↗
PubMed2003

Analysis of photo-pattern sensitivity in patients with Pokemon-related symptoms.

This study was designed to analyze photo-pattern sensitivity in patients who developed acute neurologic symptoms associated with watching an animated television program, "Pokemon." The 18 patients (13 females and five males) underwent electroencephalograms and photo-pattern stimulation testing, including special stimulation test batteries (strobe-pattern test and cathode ray tube-pattern test). Photo-pattern sensitivity was confirmed in 16 patients with and without seizure episodes. The strobe-pattern test including a white flickering light test (with eyes open, closed, and open or closed), and the cathode ray tube-pattern test each induced a photo-paroxysmal response in more than 80% of patients. However, with the eyes closed only, as is common in Japan, the photo-paroxysmal response induction rate with a white flickering light stimulus was significantly lower (43%). In the cathode ray tube-pattern test, higher spatial frequencies produced higher rates of photo-paroxysmal response induction. It was demonstrated that underlying photo-pattern sensitivity is more accurately investigated by our method than by standard intermittent photic stimulation alone. By characterizing underlying photo-pattern sensitivity and identifying predisposing factors more precisely, we can develop better guidelines for prevention of a second "Pokemon" incident. According to the results of the present cathode ray tube-pattern test, pattern sensitivity (especially spatial resolution) appears to also be involved in Pokemon-related symptoms, in addition to chromatic sensitivity.

Adolescent↗
PubMed1989

Vertical offsets of horizontal recti muscles in the management of A and V pattern strabismus.

Vertical transposition of the horizontal rectus muscles is the preferred operation in cases of A and V pattern strabismus in which oblique muscle dysfunction is inadequate to merit oblique surgery. Fifty-nine patients undergoing standard horizontal surgery with half tendon width vertical offsets and eight patients undergoing two-thirds to full tendon width offsets were retrospectively studied. Technique for pattern measurement and surgery are discussed. Postoperative data were analysed on a short-term (less than six weeks) and long-term (greater than 12 months) basis. Standard horizontal surgery combined with half-tendon width vertical transposition is shown to be an effective operation for collapsing all subgroups of A and V pattern strabismus when indications are appropriate. The initial correction to within +/- 10 D of pattern was 96% over all with 78% remaining collapsed to within +/- 10 D over an average 36-month follow-up. Recess-resect, bimedial and bilateral rectus recession operations with offsets are all approximately equally effective in pattern collapse. A graded pattern collapse response was found with greater collapse being related to greater initial pattern. The risk of conversion, from a more desirable pattern (AET, VXT) to a less desirable pattern (AXT, VET) is low (7.3%). For patterns greater than 30 D, three quarters to full-tendon width offsets were effective in collapsing pattern. For A and V patterns with significant oblique muscle dysfunction, oblique surgery is advocated.

Follow-Up Studies↗
PubMed1981

Pattern-onset visual evoked potentials in suspected multiple sclerosis.

Visual evoked potentials (VEPs) were obtained by monocular stimulation using a checkerboard pattern-reversal and pattern-onset technique. In 11 normal subjects, pattern-onset VEPs were generally larger, better defined, and less ambiguous than those elicited by pattern-reversal, because of the biphasic waveform characteristically obtained with pattern-onset stimulation. In 68 of 105 patients with possible multiple sclerosis, VEPs were normal in latency by both methods, and in nine adequate comparison was not possible. The incidence of normal VEPs to pattern-reversal was similar to that found in several other studies of patients with possible multiple sclerosis. Among the remaining 28 patients in whom VEP abnormalities were found, an increased latency was detected in 75% with the pattern-reversal technique, and in 96% by pattern-onset. In these patients, VEP abnormalities were obtained by monocular stimulation of each of 46 eyes, and among these the pattern-reversal technique yielded abnormalities in 59% and the pattern-onset method in 98%. These results indicate that VEPs elicited by pattern-onset are useful in investigating patients with suspected multiple sclerosis, and the diagnostic yield may be greater than with conventional pattern-reversal techniques.

Adult↗
PubMed2006

Locating previously unknown patterns in data-mining results: a dual data- and knowledge-mining method.

BACKGROUND: Data mining can be utilized to automate analysis of substantial amounts of data produced in many organizations. However, data mining produces large numbers of rules and patterns, many of which are not useful. Existing methods for pruning uninteresting patterns have only begun to automate the knowledge acquisition step (which is required for subjective measures of interestingness), hence leaving a serious bottleneck. In this paper we propose a method for automatically acquiring knowledge to shorten the pattern list by locating the novel and interesting ones. METHODS: The dual-mining method is based on automatically comparing the strength of patterns mined from a database with the strength of equivalent patterns mined from a relevant knowledgebase. When these two estimates of pattern strength do not match, a high "surprise score" is assigned to the pattern, identifying the pattern as potentially interesting. The surprise score captures the degree of novelty or interestingness of the mined pattern. In addition, we show how to compute p values for each surprise score, thus filtering out noise and attaching statistical significance. RESULTS: We have implemented the dual-mining method using scripts written in Perl and R. We applied the method to a large patient database and a biomedical literature citation knowledgebase. The system estimated association scores for 50,000 patterns, composed of disease entities and lab results, by querying the database and the knowledgebase. It then computed the surprise scores by comparing the pairs of association scores. Finally, the system estimated statistical significance of the scores. CONCLUSION: The dual-mining method eliminates more than 90% of patterns with strong associations, thus identifying them as uninteresting. We found that the pruning of patterns using the surprise score matched the biomedical evidence in the 100 cases that were examined by hand. The method automates the acquisition of knowledge, thus reducing dependence on the knowledge elicited from human expert, which is usually a rate-limiting step.

Algorithms↗
PubMed2005

Identification of functional modules in protein complexes via hyperclique pattern discovery.

Proteins usually do not act isolated in a cell but function within complicated cellular pathways, interacting with other proteins either in pairs or as components of larger complexes. While many protein complexes have been identified by large-scale experimental studies, due to a large number of false-positive interactions existing in current protein complexes 10, it is still difficult to obtain an accurate understanding of functional modules, which encompass groups of proteins involved in common elementary biological function. In this paper, we present a hyperclique pattern discovery approach for extracting functional modules (hyperclique patterns) from protein complexes. A hyperclique pattern is a type of association pattern containing proteins that are highly affiliated with each other. The analysis of hyperclique patterns shows that proteins within the same pattern tend to present in the protein complex together. Also, statistically significant annotations of proteins in a pattern using the Gene Ontology suggest that proteins within the same hyperclique pattern more likely perform the same function and participate in the same biological process. More interestingly, the 3-D structural view of proteins within a hyperclique pattern reveals that these proteins physically interactwith each other. In addition, we show that several hyperclique patterns corresponding to different functions can participate in the same protein complex as independent modules. Finally, we demonstrate that a hyperclique pattern can be involved in different complexes performing different higher-order biological functions, although the pattern corresponds to a specific elementary biological function.

Algorithms↗
PubMed1997

Distinct angiogenic patterns are associated with high-grade in situ ductal carcinomas of the breast.

Angiogenesis, the formation of new blood vessels from the existing vascular network, has been demonstrated to be an important prognostic factor in invasive breast carcinoma. The switch to an angiogenic phenotype represents a growth-limiting step during carcinogenesis and might, in pre-invasive lesions, indicate the risk for developing an invasive phenotype. The discrepancy between modern therapy options for invasive breast carcinomas and the relatively aggressive treatment of in situ lesions underlines the need for such prognostic factors for ductal in situ breast carcinomas (DCIS). Patterns of vascularity were examined in 75 formalin-fixed, paraffin-embedded DCIS by immunohistochemical staining of vessels using antibodies against Factor VIII-related antigen. Histological classification was performed according to four different systems, based on architectural or cytonuclear features, or a combination of both. Two distinct vascular patterns were observed: a diffuse increase of stromal vascularity between duct lesions (pattern I), which was present alone in 8/75 (11 per cent), and a dense rim of microvessels adjacent to the basement membrane of individual ducts (pattern II), present alone in 12/75 (16 per cent). In total, 57 per cent (43/75) showed pattern 1 and 62 per cent (47/75) showed pattern II. There was a significant correlation between these patterns (P = 0.0001; chi 2 = 15.1), such that both were present in 35 (47 per cent). These different vascular patterns imply two angiogenic pathways: one pathway mediated by angiogenic factors released directly by tumour cells resulting in the rim of vessels and another generated indirectly via recruitment of accessory cells such as macrophage and endothelial cells, which themselves release other angiogenic factors, causing the increase of stromal vascularity. A significant increase in both stromal vascularity (pattern I) and the presence of a rim (pattern II) was observed in high-grade DCIS lesions (P = 0.005 and P = 0.037). Indeed, all the patient relapses occurred in these high-grade lesions, but due to the small number of patient events, no significant correlation of vascular pattern to survival was observed (P > 0.05). This study suggests that distinct patterns of vascularity in DCIS might be useful for identifying patients who are at risk of relapse.

Adult↗
PubMed1984

Patterns of bone marrow involvement in chronic lymphocytic leukemia and small lymphocytic (well differentiated) non-Hodgkin's lymphoma. Its clinical significance in relation to their differential diagnosis and prognosis.

Forty-eight patients with chronic lymphocytic leukemia (CLL), and 12 patients with small (well differentiated) lymphocytic lymphoma (WDL) were histologically evaluated for their pattern of bone marrow (BM) involvement. Four different types of BM infiltration were recognized: nodular (N), interstitial (I), nodular and interstitial (mixed) and diffuse (D). The pattern of BM involvement was compared with the clinical, laboratory, and survival status in all patients. The extent of the disease in CLL patients, was determined by the Rai and the International Workshop on CLL Staging Systems, while in WDL patients the Ann Arbor staging system was used. In the CLL group the N pattern was found in 8%, the I in 33%, the mixed in 31%, and the D in 27% of the patients. Based on the International Workshop on CLL Staging System, the I pattern of BM involvement was more frequently found in Stage A (56%), the mixed in Stage B (68%), and the D in Stage C disease (90%). All CLL patients with D pattern required treatment from the beginning, contrary to CLL patients with the other patterns, in whom therapy was required in less than 50%. Similarly, deaths were more common in the D pattern in whom therapy pattern than in the other patterns. In the WDL patients BM involvement was found in 4 of 12, (33%) and its pattern of positivity was always nodular, although most patients (10 of 12) had advanced disease. It is concluded that the frequency of BM involvement may contribute in the differential diagnosis of WDL from CLL. In addition, the pattern of BM infiltration correlates very well with the International Staging System for CLL, and the pattern of BM positivity in CLL patients also has prognostic significance.

Adult↗
PubMed2004

Patterns of tooth crown size and shape variation in great apes and humans and species recognition in the hominid fossil record.

It has been suggested that patterns of craniodental variation in living hominids (Gorilla, Homo, Pan, and Pongo) may be useful for evaluating variation in fossil hominid assemblages. Using this approach, a fossil sample exhibiting a pattern of variation that deviates from one shared among living taxa would be regarded as taxonomically heterogeneous. Here we examine patterns of tooth crown size and shape variation in great apes and humans to determine 1) if these taxa share a pattern of dental variation, and 2) if such a pattern can reliably discriminate between samples that contain single species and those that contain multiple species. We use parametric and nonparametric correlation methods to establish the degree of pattern similarity among taxa, and randomization tests to assess their statistical significance. The results of this study show that extant hominids do not share a pattern of dental size variation, and thus these taxa cannot be used to generate expectations for patterns of size variation in fossil hominid species. The hominines (Gorilla, Homo, and Pan) do share a pattern of shape variation in the mandibular dentition; however, Pongo is distinct, and thus it is unclear which, if either, pattern should be expected in fossil hominids. Moreover, in this case, most combined-species samples exhibit patterns of shape variation that are similar to those for single hominine species samples. Thus, although a common pattern of shape variation is present in the mandibular dentition, it is not useful for recognizing taxonomically mixed paleontological samples.

Animals↗
PubMed1989

Spatial patterns of human gene frequencies in Europe.

The aims of this study of spatial patterns of human gene frequencies in Europe are twofold. One is to present new methodology developed for the analysis of such data. The other is to report on the diversity of spatial patterns observed in Europe and their interpretation as evidence of population processes. Spatial variation in 59 allele and haplotype frequencies (26 genetic systems) for polymorphisms in blood antigens, enzymes, and proteins is analyzed for an aggregate of 3,384 localities, using homogeneity tests, one-dimensional and directional spatial correlograms, and SYMAP interpolated surfaces. The data matrices are reduced to reveal the principal patterns by clustering techniques. The findings of this study can be summarized as follows: 1) There is significant heterogeneity in allele frequencies among the localities for all but one genetic system. 2) There are significant spatial patterns for most allele frequencies. 3) There is a substantial minority of clinal patterns in these populations. Clinal trends are found more frequently in HLA alleles than for other variables. North-south and northwest-southwest gradients predominate. 4) There is a strong decline in overall genetic similarity with geographic distance for most variables. 5) There are few, if any, appreciable correlations in pairs of allele frequencies over the continent, and there is little interesting correlation structure in the resulting correlation matrix. 6) Few spatial correlograms are markedly similar to each other, yet they form well-defined clusters. Spatial variation patterns, therefore, differ among allele frequencies. Patterns of human gene frequencies in modern Europe are diverse and complex. No single model suffices for interpretation of the observed genetic structure. Some clinal patterns reported here support the Neolithic demic-expansion hypothesis, others suggest latitudinal selection. Most of the clinal patterns are in HLA alleles, but there is also evidence from ABO for east-west migration diffusion. The majority of patterns are patchy, consistent with hypotheses of isolation by distance or of settlement of genetically differing, subsequently expanding ethnic groups. While undoubtedly there has been an ongoing stochastic process of differentiation consistent with the isolation-by-distance model, this has not obscured the directional patterns caused by migration (demic diffusion), and has perhaps only reinforced the contribution from settlement of ethnic units to patterns of genetic variation. However, the impact of the latter is most difficult to discern and requires further methodological developments.

ABO Blood-Group System↗
PubMed2005

Three basic patterns of changes in serum thyroid hormone levels in Graves' disease during the one-year period after radioiodine therapy.

UNLABELLED: The purpose of this study was to clarify the characteristic patterns of the thyroid hormonal changes in Graves' disease during the one-year period after 131I therapy considering that few serial hormonal data during this period are available in the literature. METHODS: The levels of serum T3, T4 and FT4 before and during one year were plotted as a function of time in 70 therapy courses of 58 patients without subsequent antithyroid or steroid therapy. RESULTS: 35 euthyroid, 6 hypothyroid and 29 hyperthyroid states were obtained during one year after therapy. Although individual patients had individual hormonal changing patterns, 3 common basic patterns were observed from baseline to one month (early) and thereafter (late), respectively. The early patterns were a decrease in 54 (77%), a minimum change in 8 (11.5%) and an increase in 8 (11.5%). The late patterns were a stable state after an initial decrease with a bottom followed by an increase (valley pattern) in 47 (67%), a stable state after an initial increase with a peak followed by a decrease with a bottom and a subsequent re-increase (mountain pattern) in 12 (17%) and a late stable state after a gradual slow decrease without an obvious bottom near or till one year (downhill pattern) in 11 (16%). The bottom level and the degree of hormonal recovery from the bottom determined the stable euthyroid, hypothyroid or hyperthyroid state in 49 (86%) of 57 with the valley or mountain pattern. Most of the bottom levels (81%) and transient abnormal changes including transient hypothyroidism (93%, 13/14), peak or hyperthyroidism (85%, 11/13) and euthyroidism (67%, 10/15) appeared within 6 months. The post-therapeutic stable euthyroid, hypothyroid or hyperthyroid state could be judged from the hormonal patterns in 57% (39/68) from 2.5 to 6 months, in 18% (12/68) from 6 to 9 months and in 25% (17/68) thereafter. CONCLUSION: Although the changes in thyroid hormones are not constant in Graves' disease during one year after 131I therapy, there are three basic patterns; valley, mountain and downhill patterns from one month after therapy. The post-therapeutic stable state can be judged by the hormonal level recovered from the bottom in most patients.

Administration, Oral↗
PubMed2000

Size, node status and grade of breast tumours: association with mammographic parenchymal patterns.

A case-control study was designed to assess the association of mammographic parenchymal patterns with the risk of in-situ and invasive breast cancer. In addition, the relationship between tumour characteristics and mammographic patterns were also investigated. A total of 875 patients with breast cancer were selected and matched with 2601 controls. Mammographic parenchymal patterns of breast tissue were assessed according to Wolfe's classification, and statistical analysis was by conditional logistic regression. Relative to the N1 pattern, the odds ratios of having an invasive breast cancer associated with the P2 and DY patterns were 1.8 and 1. 4, respectively. In addition, the odd ratios of having an invasive grade 3 breast cancer associated with the P2 and DY patterns were 2. 8 and 3.9, respectively. Relative to the combined N1/P1 pattern, the odd ratios of having a breast cancer smaller than 14 mm, 15-29 mm, or larger than 30 mm associated with the combined high-risk P2/DY pattern (P2 + DY) were 1.2, 1.6, and 2.0, respectively. Finally, women with the P2/DY pattern were twice as likely to have a breast cancer which had already spread to the axillary nodes, compared to women with women with the N1/P1 pattern (odds ratios of 2.1 and 1.4, respectively). Our results confirm previous findings suggesting that mammographic parenchymal patterns may serve as indicators of risk for breast cancer. Our results also suggest that mammographic parenchymal patterns are associated with the stage at which breast cancer is detected.

Breast Neoplasms↗
PubMed2001

Zebrafish hybrids suggest genetic mechanisms for pigment pattern diversification in Danio.

Pigment patterns of Danio fishes are a tractable system for assessing the developmental genetic bases for the evolution of adult form in vertebrates. These pigment patterns include multiple horizontal melanophore stripes in the zebrafish D. rerio, a complete absence of stripes in D. albolineatus, a few broad stripes in D. kerri, and a combination of stripes and spots in D. nigrofasciatus. Here we assess the genetics of pigment pattern development and evolution using interspecific hybrids. We first reconstruct the phylogenetic relationships of these species by analyzing mitochondrial 12S and 16S rDNA sequences. We find a clade comprising several small species of danio, and within this clade a sister taxon relationship between D. rerio and D. nigrofasciatus. We also find that the large bodied D. dangila is more closely related to the clade of small danios than other large bodied species. As a first step in evaluating the genetics of pigment pattern diversification in the group, we then examine the phenotypes of interspecific hybrids. Adult pigment patterns of hybrids between D. rerio and other danios are in many respects more similar to D. rerio than the heterospecific danio, demonstrating that alleles of pigment pattern genes in other species typically are recessive to D. rerio alleles. Furthermore, hybrids between two additional striped species (D. kerri, D. nigrofasciatus) and D. albolineatus suggest that striped patterns are dominant or semi-dominant over an absence of stripes. Together, these analyses support a model in which pigment pattern differences between D. rerio and other species result from gain-of-function alleles in D. rerio, or loss-of-function alleles in other danios. Finally, because several D. rerio pigment pattern mutants resemble heterospecific danios, we use interspecific complementation tests to assess potential roles for these loci in pigment pattern diversification. Crosses between other danios and most D. rerio pigment pattern mutants develop stripes, similar to control hybrids with wild-type D. rerio. These complementation phenotypes allow us to exclude most of these loci as having major effect roles in generating pigment pattern differences between species. In contrast, hybrids between fms mutant D. rerio and D. albolineatus fail to develop stripes, similar to D. albolineatus. This non-complementation phenotype identifies changes in fms, or the pathway in which it acts, as candidates for contributing to the evolutionary loss of stripes in D. albolineatus.

Animals↗
PubMed2005

Peak pattern variations related to comprehensive two-dimensional gas chromatography acquisition.

Identifying compounds of interest for peaks in data generated by comprehensive two-dimensional gas chromatography (GC x GC) is a critical analytical task. Manually identifying compounds is tedious and time-consuming. An alternative is to use pattern matching. Pattern matching identifies compounds by matching previously observed patterns with known peaks to newly observed patterns with unidentified peaks. The fundamental difficulty of pattern matching comes from peak pattern distortions that are caused by differences in data acquisition conditions. This paper investigates peak pattern variations related to varying oven temperature ramp rate and inlet gas pressure and evaluates two types of affine transformations for matching peak patterns. The experimental results suggest that, over the experimental ranges, the changes in temperature ramp rate generate non-linear pattern variations and changes in gas pressure generate nearly linear pattern variations. The results indicate the affine transformations can largely remove the pattern variations and can be used for applications such as pattern matching and normalizing retention times to retention indices.

Chromatography, Gas↗
PubMed2006

The role of bright liver echo pattern on ultrasound B-mode examination in the diagnosis of liver steatosis.

AIM: The observation of bright liver echo pattern on ultrasound is commonly considered a sign of hepatic steatosis. However, the interference of liver fibrosis on sensitivity and specificity of bright liver echo pattern has caused many to question its effectiveness as a diagnostic tool. The objective of this study was to evaluate the sensitivity, specificity and predictive values of bright liver echo pattern for liver steatosis. PATIENTS AND METHODS: We studied 235 consecutive patients suspected of having liver disease of various aetiologies. Median age was 52 years (range, 17-72 years), and there was a male/female ratio of 1:18. All patients underwent ultrasound examination before liver biopsy and was performed by two operators. The presence or absence of bright liver echo pattern and posterior attenuation or areas with different patterns of fat infiltration were noted. Histologic evaluation was performed and graded by Ishak score. Steatosis was categorised as absent, 0-2%, 3-29% to 30-49% or >50%. RESULTS: Interobserver concordance was high. Bright liver echo pattern was found in 67% of patients with steatosis of any degree and 89% of patients with steatosis of >or=30%. Only three patients without steatosis, who had a low Ishak score, demonstrated bright liver echo pattern on ultrasonography. The sensitivity, specificity, positive predictive value and negative predictive value of bright liver echo pattern for steatosis were 64%, 97%, 96.0% and 65%, respectively. Among the subgroup of patients who had steatosis of >or=30%, the sensitivity, specificity, positive predictive value and negative predictive value of bright liver echo pattern were 91%, 93%, 89% and 94%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of posterior attenuation and/or skip areas associated with bright liver echo pattern for steatosis were 89.7%, 100%, 100% and 92.3%, respectively. Univariate analysis showed bright liver echo pattern to be associated only with steatosis and not with fibrosis. CONCLUSION: We concluded that the presence of bright liver echo pattern is a sign of liver steatosis and that liver fibrosis does not interfere with ultrasound measurements. Posterior attenuation and/or skip areas are closely related to steatosis of >or=30%.

Adolescent↗
PubMed2001

Microcirculation patterns other than loops and networks in choroidal and ciliary body melanomas.

PURPOSE: To provide ophthalmologists and pathologists with expanded criteria for separating patients at high risk of metastatic melanoma from those at low risk on the basis of microcirculation patterns in choroidal and ciliary body melanomas. DESIGN: Tissue culture studies and observational case series. PARTICIPANTS: The pattern-forming ability of four uveal melanoma cell lines of varying degrees of aggressive behavior was studied in vitro. Histologic sections of 234 eyes removed for choroidal or ciliary body melanoma were studied for the presence of microcirculation patterns. METHODS: The study was divided into two phases: the study of histologic sections of eyes removed for choroidal and ciliary body melanomas and observations on the in vitro behavior of cultured melanoma cells of varying degrees of invasive behavior. The presence or absence of each of nine microcirculation patterns was recorded from tissue sections, and interrelationships between different patterns were explored statistically. In vitro reconstitution of patterns and a study of the interrelationships of patterns in histologic sections was carried out. In the in vitro studies, uveal melanoma cell lines of varying degrees of aggressive potential were cultured to observe the development of architectural patterns other than loops and networks. MAIN OUTCOME MEASURES: In histologic studies, the outcome measure was the conditional probability of detecting loops or networks given the presence or absence of other patterns positive for periodic acid-SCHIFF: For tissue culture studies, the outcome measure was either the development or lack of development of patterns of different shapes in vitro. RESULTS: Histologic studies disclosed that given the presence of arcs without or with branching in a tissue section, it is likely that loops or networks will be detected in the same section plane, suggesting that the production of these patterns by aggressive tumor cells reflects a spectrum of architectural potential. In vitro studies confirmed this hypothesis by revealing that highly aggressive and metastatic uveal melanoma cell lines, but not poorly aggressive tumor cell lines, generated parallel channels with and without crosslinking and arcs with and without branching as well as loops and networks. CONCLUSIONS: The criteria for separating patients into low- and high-risk categories for metastasis from uveal melanoma should be expanded to include patterns other than loops or networks. In both the pathology laboratory as well as in a clinical setting, the detection of arcs or arcs with branching and parallel channels should prompt a careful search for loops and networks and for crosslinking parallel channels, respectively.

Choroid Neoplasms↗
PubMed2003

Genetic susceptibility and dietary patterns in lung cancer.

Cigarette smoking is the dominant risk factor for lung cancer, but only a minority of smokers ever develops tumors. Though genetic susceptibility is likely to explain some of the variability in risk, results from previous studies of genetic polymorphisms have been inconclusive. As diet may also affect the risk of lung cancer, it is possible that the degree of risk produced by smoking and genetic susceptibility varies, depending on diet. To assess this hypothesis, we conducted a case-control study to examine the effect of cigarette smoking, dietary patterns and variation in genes involved in phase II metabolism. A total of 254 individuals with lung cancer and 184 healthy controls were recruited for the study. To identify persons with similar dietary patterns, cluster analysis was performed using nutrient densities of four major dietary constituents: protein, carbohydrate, animal fat, and dietary fiber. Two groups of individuals were identified with distinct dietary patterns: (1) a group (n=241) with a high intake of animal fat and protein and a low intake of carbohydrates and dietary fiber (the 'unhealthy' pattern) and (2) a group (n=197) with a high intake of fiber and carbohydrate and a low intake of protein and animal fat (the 'healthy' pattern) [corrected]. On stratified analysis, several genotype/dietary pattern combinations were found to affect risk of lung cancer. Smokers who were not homozygous for the most common GSTP1 allele and had a healthy dietary pattern were at significantly lower risk than smokers who were homozygous for the GSTP1 common allele and who had an unhealthy dietary pattern (OR=0.16, 95%CI: 0.04-0.57). Among smokers who were GSTM1 null, persons with a healthy dietary pattern were at lower risk than persons with an unhealthy dietary pattern (OR: 0.46, 95%CI: 0.21-1.01). Among smokers with an unhealthy dietary patterns, persons with a His/His genotype in the exon 3 polymorphism of EPHX1 were at significantly lower risk that persons who were not homozygous. These data suggest that dietary factors may affect the risk imposed by genetic susceptibility at detoxification loci. Adjustments using dietary pattern may be useful in elucidating the effects of polymorphisms in genes responsible for carcinogen metabolism.

Adult↗