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PubMed2004

Metastatic potentiality of micropapillary and conventional histological patterns: a comparative study of 82 pulmonary adenocarcinomas.

BACKGROUND: The recently described micropapillary pattern (MPP) is potentially a strong unfavorable prognostic marker for adenocarcinoma of the lung. None of the previous studies compared the association to nodal metastasis between conventional histological patterns and MPP. METHOD: Histological patterns (1=solid, 2=poorly formed acinar 3=well formed acinar, 4=papillary, 5=bronchioloalveolar), and MPP were semiquantitatively evaluated in 82 pulmonary adenocarcinomas and correlated with nodal status. RESULTS: Mean percentages of pattern 1 and 2 are higher in node positive (N+) group (33.9% vs 19.3%, p=0.046; and 20.8% vs 13.4%, p=0.19, respectively). Analysis of the combined amount of pattern 1 and 2 revealed increased statistical significance (54.6% vs 32.5%, p=0.007). Mean percentages of pattern 3, 4 and 5 tended to be lower in N+ group (22.8% vs 29.4%, p=0.24; 2.8% vs 6.2%, p=0.33; and 17.9% vs 31.2%, p=0.053, respectively). Analysis of the combined amount of pattern 3, 4 and 5 showed increased statistical significance (43.3% vs 66.8%, p=0.005). Mean percentage of MPP was higher in N+ group (28.3% vs 11.3%, p=0.0007) after excluding the cases with more than 80% percent of pattern 1 and 2. The criterion of MPP > or = 20% or combined pattern 1 and 2 > 50% of tumor is strongly associated with nodal metastasis (p=0.0015). Pattern 1 has the highest rate of correspondence of having a similar pattern in metastases (18/26, 69.2%), followed by MPP (10/19, 52.6%), and pattern 2 (12/23, 52.2%). CONCLUSION: MPP has comparable metastatic impact to the solid and the poorly formed acinar patterns and it is prognostically informative to document the presence or absence of the solid plus poorly formed glandular pattern > 50% and MPP > or = 20% when histological subtype is evaluated.

Adenocarcinoma↗
PubMedDate not supplied

Delineation of the various shapes and patterns of nevi.

It has been proposed that all nevi reflect mosaicism, and this concept has been corroborated at the molecular level in a number of nevi. If the concept of mosaicism holds true, one would expect that the various types of nevi should be characterized by intrinsic shapes or patterns. A photographic review of 1,188 recognizable images of a list of nevi of the skin was undertaken in order to delineate a classification of the various shapes and patterns of nevi. We disclosed three distinct shapes and two so far undescribed archetypical patterns, in addition to the well-known Blaschko-linear, flag-like and extensive garment-like patterns, to which all lesions could be allocated. The newly delineated shapes are called round or oval shape; patches with indented borders; and teardrop or triangular shape. The newly proposed archetypical configurations are the agminated pattern and the diffuse patchy pattern. Other mosaic patterns, such as the phylloid pattern or the lateralization pattern, were not observed in any of the images reviewed. We conclude that the various types of nevi can be assigned to specific shapes or patterns. Admittedly, however, a given nevus may manifest itself in several different shapes, whereas its archetypical pattern tends to be the same. This 'archetypical' pattern can be taken as the perfect or ideal model of a given type of nevus, whereas the newly described shapes are subordinated to the archetypical patterns and are best considered to be 'nonarchetypical'. Our work gives more consistency to the idea that nevi reflect mosaicism, because they display repetitive shapes and patterns.

Child↗
PubMed2005

[Association of clinical features with different hemodynamic patterns in head-up tilt test in children with unexplained syncope].

OBJECTIVE: To explore the different hemodynamic patterns during the course of head-up tilt tests in children with unexplained syncope and the association of clinical features with different hemodynamic patterns in head-up tilt test in children with unexplained syncope. METHODS: 100 pediatric patients with unexplained syncope, aged 11 +/- 2 (6-16), 36 male and 64 female, with the mean course of 10 +/- 16 months (2 d-5 y), underwent head-up tilt tests or head-up tilt tests potentiated with nitroglycerine under quiet circumstance. Blood pressure and heart rate were monitored simultaneously. According to their different hemodynamic patterns, they were divided into vasovagal response pattern, postural orthostatic tachycardia syndrome (POTS) response pattern, orthostatic hypotension (OH) response pattern and normal response pattern. The vasovagal response was divided into vasodepressor, cardioinhibitory and mixed patterns. The distribution and different clinical features of different response patterns in the unexplained syncope were also studied. RESULTS: Fifty (50%) of the 100 children with unexplained syncope displayed the hemodynamic pattern of vasovagal response, among which 31 (31%) displayed the pattern of vasodepressor response, 7 (7%) cardioinhibitory response, and 12 (12%) mixed response. Thirty-three patients (33%) displayed POTS response, 2 (2%) OH response, and 15 (15%) the normal hemodynamic response. Patterns of dysautonomic response and chronotropic incompetence were not observed in these children with unexplained syncope. The age of the children with normal response during HUT was 10 +/- 3 years, significantly younger than that of the children with vasovagal response and POTS response (12 +/- 2 and 12 +/- 2, both P < 0.01). There were no differences in sex ratio and duration of syncope among the vasovagal response, POTS and normal response. But the syncopal spells in the children with POTS response was less frequent and the baseline heart rate of the children with POTS response was 81 +/- 7, significantly faster than that of the children with vasovagal response and normal response (71 +/- 9 and 74 +/- 7, both P < 0.01). There was no significant difference in the baseline blood pressure among the children with vasovagal response, POTS and normal response. There were also no significant differences in the age, sex ratio, and duration of syncope, number of syncopal spells, baseline heart rate, and baseline blood pressure among the children with vasodepressor response, cardioinhibitory response and mixed response. CONCLUSION: There are different hemodynamic response patterns in head-up tilt testing in children with unexplained syncope, and there was some association between hemodynamic response patterns and their clinical features.

Adolescent↗
PubMed1993

A clonal study of hematopoiesis using the M27 beta probe: aberrant band patterns caused by incomplete digestion of a methyl-sensitive enzyme in the the inactive X-chromosome.

The M27 beta probe has been used to determine the clonality of human tumors, based upon X-chromosome inactivation. However, it occasionally gives rise to aberrant results. In this study, the M27 beta probe was used for clonal analysis in Japanese women with clonal stem cell disorders and in those with normal hematopoiesis. Restriction digestion with PstI indicated heterozygosity for the DXS255 locus in 41 out of 50 individuals (82%). Further digestion with HpaII in heterozygous women led to four distinct band patterns: I, both fragments were partially digested; II, either one of the two fragments was completely digested; III, a three-band pattern; and IV, neither fragment was digested. Of 21 hematologically normal females, 17 (81%) and four (19%) had patterns I and III, respectively. In some subjects with pattern I, imbalanced HpaII digestion in the two alleles was seen. Fifteen (65%) of the 23 patients with clonal stem cell disorders had pattern II, while the remainder (35%) had pattern IV. The normal tissues of three acute myeloid leukemia patients with pattern IV all revealed pattern I. It is possible that the aberrant band patterns could be caused by incomplete HpaII digestion in inactive X-chromosomes. In this study, we propose a hypothesis whereby, in normal tissues, aberrant cells, the DXS255 locus of which is not digested with HpaII despite their inactive status, would be mixed with cells demonstrating the usual methylation pattern. In normal tissues, complex of proportion of aberrant cells and skewed Lyonization could produce a variety of band patterns. If a cell with the usual methylation pattern proliferated monoclonally, pattern II would be seen: whereas if an aberrant cell proliferated, pattern IV would be demonstrated.

Blotting, Southern↗
PubMed1987

Self-organizing neural network models for visual pattern recognition.

Two neural network models for visual pattern recognition are discussed. The first model, called a "neocognitron", is a hierarchical multilayered network which has only afferent synaptic connections. It can acquire the ability to recognize patterns by "learning-without-a-teacher": the repeated presentation of a set of training patterns is sufficient, and no information about the categories of the patterns is necessary. The cells of the highest stage eventually become "gnostic cells", whose response shows the final result of the pattern-recognition of the network. Pattern recognition is performed on the basis of similarity in shape between patterns, and is not affected by deformation, nor by changes in size, nor by shifts in the position of the stimulus pattern. The second model has not only afferent but also efferent synaptic connections, and is endowed with the function of selective attention. The afferent and the efferent signals interact with each other in the hierarchical network: the efferent signals, that is, the signals for selective attention, have a facilitating effect on the afferent signals, and at the same time, the afferent signals gate efferent signal flow. When a complex figure, consisting of two patterns or more, is presented to the model, it is segmented into individual patterns, and each pattern is recognized separately. Even if one of the patterns to which the models is paying selective attention is affected by noise or defects, the model can "recall" the complete pattern from which the noise has been eliminated and the defects corrected.

Afferent Pathways↗
PubMed1991

Hemispheric asymmetries in visual pattern processing in infancy.

A right hemisphere advantage was observed in a previous study of 4- to 9-month old infants presented with a face discrimination task (de Schonen & Mathivet, 1990). The present study was designed to investigate pattern processing by the two hemispheres and the interhemispheric communication of this processing. Infants aged 4 to 9 months were tested with divided visual field presentations in one or two discrimination tasks. Under both task conditions, the infants had to discriminate between two patterns in which only two local components differed. Under one condition the components of the patterns were arranged so as to produce a face-like pattern. Under the other condition the same components were arranged into arbitrary patterns that were not "good form" patterns. No performance asymmetry was observed with the arbitrary patterns; whereas, a right hemisphere (RH) disadvantage was observed with the face-like patterns compared with both the RH performances on the arbitary patterns and the left hemisphere (LH) performances on the face-like patterns. These results show that the RH advantage for individual face recognition is not due to a general immaturity or inability of the LH in pattern processing at this period of development, nor to a more specific inability in a local mode of pattern processing. On the other hand, the RH does not completely lack local processing capacity, but is at a disadvantage when this local mode of processing has to be used with face-like (or good form) patterns. The interhemispheric communication of visual discrimination learning was tested by measuring learning transfer between the visual fields. Contrary to de Schonen and Bry's study (1987) on faceness recognition, no data in favor of interhemispheric communication were recorded in the present study.

Attention↗
PubMed2005

Labyrinthine versus straight-striped patterns generated by two-dimensional Turing systems.

Striped patterns are often observed on fish skin. Such patterns have been accounted for by reaction-diffusion (RD) Turing-type models, in which two substances can spontaneously form a spatially heterogeneous pattern in a homogeneous field. Among the striped patterns generated by Turing-type models, some are "straight-striped patterns," with many stripes running in parallel, while others are "labyrinthine patterns," in which the stripes often change direction, merge with each other, and frequently branch out. RD models differ in terms of their tendency to generate either labyrinthine or straight-striped patterns. Here, we studied the conditions under which either a labyrinthine or straight-striped pattern would emerge. First, we defined an index for stripe clearness, Sh. Straight-striped patterns (large Sh) are formed if only a narrow range of spatial periods corresponds to an unstable mode. Labyrinthine patterns (small Sh) are formed when a wide range of spatial periods is unstable. More specifically, labyrinthine patterns are formed when the maximum spatial period of unstable modes is more than twice that of the minimum spatial period of unstable modes; otherwise, straight-striped patterns are formed. We then examined RD models with nonlinear reaction terms, including both activator-inhibitor and substrate-depletion models, and we demonstrated that the same conclusions hold with respect to the conditions required for labyrinthine versus straight-striped patterns.

Animals↗
PubMed1967

Pattern classification by adaptive machines.

Man's intelligent behavior is due in part to his ability to select, classify, and abstract significant information reaching him from his environment by way of his senses. This function, pattern recognition, has become a major focus of research by scientists working in the field of artificial intelligence. At the lowest level, pattern recognition reduces to pattern classification, which consists of the separation, into desired classes, of groups of objects, sounds, odors, events, properties, and the like; the separations are based on sets of measurements made on the entities being classified. The pattern classifier is composed of a data filter and a categorizer. The data filter selects the distinguishing features and represents them as sets of real numbers; each set is termed a pattern. The categorizer assigns each pattern to one of several desired classes. Patterns can be represented geometrically as points in an n-dimensional space; the n coordinates of each point are the numerical values of the features selected to represent the pattern. A pattern classification system separates an n-dimensional space into regions, each of which ideally contains points of only one class. One method to effect this separation is by means of ldquo;trainablerdquo; categorizers-major components of adaptive machines. They consist of networks whose internal parameters are varied according to a set of fixed rules during a training cycle. A statistically large sample of known patterns are presented, one at a time, to the networks; internal corrections are made each time a pattern is erroneously classified. Classifica-tion performance tends to improve as the set of known patterns is cycled repetitively through the machine. Finally, the adequacy of adaptation is tested by a separate set of similar patterns which have not been used in the training process. A number of different machine organizations and training rules have been developed and are being applied successfully to numerous classification problems. More difficult recognition problems requiring the aid of logioal tests and analysis, search and association, use the digital computer programmed to supplement the functions of the adaptive classifier.

Body Constitution↗
PubMed2001

Acquisition and analysis of repeating patterns in time-oriented clinical data.

OBJECTIVES: (1) Creation of an expressive language for specification of temporal patterns in clinical domains, (2) Development of a graphical knowledge-acquisition tool allowing expert physicians to define meaningful domain-specific patterns, (3) Implementation of an interpreter capable of detecting such patterns in clinical databases, and (4) Evaluation of the tools in the domains of diabetes and oncology. METHODS: We describe a constraint-based language, named CAPSUL, for specification of temporal patterns. We implemented a knowledge-acquisition tool and a temporal-pattern interpreter within Résumé, a larger temporal-abstraction architecture. We evaluated the knowledge-acquisition process with the help of domain experts. In collaboration with the Rush Presbyterian/St. Luke's Medical Center, we analyzed data of bone-marrow transplantation patients. The expert compared the detected patterns to a manual inspection of the data, with the help of an experimental information-visualization tool we are developing in a related project. RESULTS: The CAPSUL language was expressive enough during the knowledge-acquisition process to capture almost all of the patterns that the experts found useful. The patterns detected in the data by the pattern interpreter were all verified as correct. Completeness (whether all correct patterns were found) was difficult to assess, due to the size of the database. CONCLUSIONS: The CAPSUL language enables medical experts to express temporal patterns involving multiple levels of abstraction of clinical data. The ability to reuse both domain-patterns and abstract constraints seems highly useful. The Résumé interpreter, augmented by the CAPSUL semantics, finds the complex patterns within a clinical time-oriented database in a sound fashion.

Algorithms↗
PubMed1999

Development and evolution of melanophore patterns in fishes of the genus Danio (Teleostei: Cyprinidae).

Pigmentation patterns in vertebrates have become an important model for those interested in mechanisms of pattern determination. I present detailed information on the development of melanophore patterns in the zebrafish, Danio rerio, five close relatives of that species, and an outgroup. The comparison of the ontogeny of melanophore patterns in this group is an important first step towards understanding the developmental basis of the interspecific variation. Pigment patterns in this group range from no distinct patterning at all to stripes of differing numbers and widths to reticulated stripes. Species examined form identical larval patterns and follow a common sequence of events from which different elements are eliminated or altered to produce the variety of patterns seen in the group. As flexion is completed, melanophores move from larval positions onto the flanks of the fish. In D. rerio, D. rerio 'leo,' D. kerri, and D. malabaricus, xanthophores become established on the body of the fish as the melanophores move; erythrophores become established on the flanks of D. albolineatus and D. sp. cf. aequipinnatus. An increase in melanophore number, begun at this time, continues at a higher rate in D. rerio, D. kerri, D. sp. cf. aequipinnatus and Tanichthys albonubes than in the other three species. This results in a greater number of melanophores on adults in those species with a higher rate of melanophore increase. No distinct pattern forms, except on the caudal peduncle, in D. albolineatus. In all other Danio species, melanophore stripes form first below then above the horizontal myoseptum. Additional stripes are added first below then above these initial two stripes. D. kerri develops fewer, wider melanophore stripes than D. rerio. After initial stripe formation, D. malabaricus and D. sp. cf. aequipinnatus both developed vertical pattern elements and reticulations in the melanophore pattern. Differences in patterns between species are similar in several cases to described mutants of the zebrafish, suggesting that some aspects of interspecific pigmentation pattern variation may be under relatively simple genetic control. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗
PubMed2001

Elements of butterfly wing patterns.

The color patterns on the wings of butterflies are unique among animal color patterns in that the elements that make up the overall pattern are individuated. Unlike the spots and stripes of vertebrate color patterns, the elements of butterfly wing patterns have identities that can be traced from species to species, and typically across genera and families. Because of this identity it is possible to recognize homologies among pattern elements and to study their evolution and diversification. Individuated pattern elements evolved from non-individuated precursors by compartmentalization of the wing into areas that became developmentally autonomous with respect to color pattern formation. Developmental compartmentalization led to the evolution of serially repeated elements and the emergence of serial homology. In these compartments, serial homologues were able to acquire site-specific developmental regulation and this, in turn, allowed them to diverge morphologically. Compartmentalization of the wing also reduced the developmental correlation among pattern elements. The release from this developmental constraint, we believe, enabled the great evolutionary radiation of butterfly wing patterns. During pattern evolution, the same set of individual pattern elements is arranged in novel ways to produce species-specific patterns, including such adaptations as mimicry and camouflage.

Adaptation, Physiological↗
PubMed1993

Early pattern recognition in severe perinatal asphyxia: a prospective MRI study.

On the basis of MRI examinations in 88 neonates and infants with perinatal asphyxia, we defined 6 different patterns on T2-weighted images: pattern A--scattered hyperintensity of both hemispheres of the telencephalon with blurred border zones between cortex and white matter, indicating diffuse brain injury; pattern B--parasagittal hyperintensity extending into the corona radiata, corresponding to the watershed zones; pattern C--hyper- and hypointense lesions in thalamus and basal ganglia, which relate to haemorrhagic necrosis or iron deposition in these areas; pattern D--periventricular hyperintensity, mainly along the lateral ventricles, i.e. periventricular leukomalacia (PVL), originating from the matrix zone; pattern E--small multifocal lesions varying from hyper--to hypointense, interpreted as necrosis and haemorrhage; pattern F--periventricular centrifugal hypointense stripes in the centrum semiovale and deep white matter of the frontal and occipital lobes. Contrast was effectively inverted on T1-weighted images. Patterns A, B and C were found in 17%, 25% and 37% of patients, and patterns D, E and F in 19%, 17% and 35%, respectively. In 49 patients a combination of patterns was observed, but 30% of the initial images were normal. At follow-up, persistent abnormalities were seen in all children with patterns A and D, but in only 52% of those with pattern C. Myelination was retarded most often in patients with diffuse brain injury and PVL (patterns A and D).

Asphyxia Neonatorum↗
PubMed1997

Phase response characteristics of model neurons determine which patterns are expressed in a ring circuit model of gait generation.

In order to assess the relative contributions to pattern-generation of the intrinsic properties of individual neurons and of their connectivity, we examined a ring circuit composed of four complex physiologically based oscillators. This circuit produced patterns that correspond to several quadrupedal gaits, including the walk, the bound, and the gallop. An analysis using the phase response curve (PRC) of an uncoupled oscillator accurately predicted all modes exhibited by this circuit and their phasic relationships--with the caveat that in certain parameter ranges, bistability in the individual oscillators added nongait patterns that were not amenable to PRC analysis, but further enriched the pattern-generating repertoire of the circuit. The key insights in the PRC analysis were that in a gait pattern, since all oscillators are entrained at the same frequency, the phase advance or delay caused by the action of each oscillator on its postsynaptic oscillator must be the same, and the sum of the normalized phase differences around the ring must equal to an integer. As suggested by several previous studies, our analysis showed that the capacity to exhibit a large number of patterns is inherent in the ring circuit configuration. In addition, our analysis revealed that the shape of the PRC for the individual oscillators determines which of the theoretically possible modes can be generated using these oscillators as circuit elements. PRCs that have a complex shape enable a circuit to produce a wider variety of patterns, and since complex neurons tend to have complex PRCs, enriching the repertoire of patterns exhibited by a circuit may be the function of some intrinsic neuronal complexity. Our analysis showed that gait transitions, or more generally, pattern transitions, in a ring circuit do not require rewiring the circuit or any changes in the strength of the connections. Instead, transitions can be achieved by using a control parameter, such as stimulus intensity, to sculpt the PRC so that it has the appropriate shape for the desired pattern(s). A transition can then be achieved simply by changing the value of the control parameter so that the first pattern either ceases to exist or loses stability, while a second pattern either comes into existence or gains stability. Our analysis illustrates the predictive value of PRCs in circuit analysis and can be extended to provide a design method for pattern-generating circuits.

Animals↗
PubMed2002

Pit pattern and three-dimensional configuration of isolated crypts from the patients with colorectal neoplasm.

BACKGROUND: This study examined the usefulness of magnifying videoscopic pit-pattern diagnosis in the differential diagnosis of colonic neoplasms. The relationship between pit patterns and the three-dimensional configuration of the neoplastic gland was evaluated for its contribution toward an understanding of pit patterns. METHODS: A total of 3005 colorectal lesions were examined endoscopically and histopathologically. Pit patterns were classified into six types. All materials used for crypt isolation were derived from segments of 21 colorectal lesions and one normal colonic mucosa. For the crypt isolation, the HCl-digestion method was used. RESULTS: The magnifying videoscopic diagnosis was comparable with the histological diagnosis in the 3005 colorectal lesions. Isolated crypts with the type-I pit pattern resembled a test-tube; the type-II pit pattern was also tubular, but had observed fissures at the bottom; the type-III l pit pattern was a reversed triangle or tongue-like in shape; and the type-III s pit pattern was columnar and either tapered off or meandered. Isolated crypts with the type-IV b pit pattern appeared as long reversed triangles with protuberances, and the type-IV v pit pattern was flat with slender tubules or finger-like processes. The isolated crypts with the type-V pit pattern were complicated and indistinct in shape. CONCLUSIONS: Evaluation of the three-dimensional configuration revealed that when the pit patterns, of each isolated crypt differed, their three-dimensional configurations also differed. Recognition of the differences in the three-dimensional configuration should contribute toward both an understanding of pit-pattern diagnosis and the further development of the endoscopic diagnosis of various colorectal lesions.

Adenoma↗
PubMedDate not supplied

Effect of eccentricity on pattern-pulse multifocal VEP.

PURPOSE: The sparse pattern-pulse stimulation has been suggested to produce better cortical evoked responses compared to pattern reversal stimulation. This study examines varying pattern-pulse states and the effect of eccentricity of the stimulated visual field on the response amplitude and latency. METHOD: The multifocal visual evoked potential (mfVEP) was recorded using Accumap. 58 close-packed checkerboard segments in a dartboard configuration were used. The best configuration for pattern-pulse stimulation was determined. This optimal stimulus condition was then compared to pattern-reversal stimulation at different eccentricities of visual field.in terms of latency and signal/noise ratio (SNR) of mfVEP amplitude. RESULTS: The maximal response was seen when each element "1" of the binary sequence was represented by two "pattern on" frames followed by two "pattern off" frames while each element "0" of the binary sequence is represented by four "pattern off" frames. There was a significant overall increase of SNR using this pattern-pulse stimulating mode (SNR=15.5+/-3.8) compared with pattern-reversal stimulation (SNR=12.4+/-2.6). However, this was strongly dependant on eccentricity. In rings 1, 2 and 3 SNR improved by 48%, 43% and 26% respectively with ring 4 the effect was marginal and ring 5 was not significantly different. There was also a significant delay (10.1+/-5.3 msec) of the mfVEP response in pattern-pulse stimulation compared to pattern-reversal. CONCLUSIONS: The pattern-pulse method offers some advantages for achieving larger mfVEP signals from the central visual field. However, the more peripheral field where it is the most difficult to obtain signals, does not show any benefit.

Evoked Potentials, Visual↗
PubMed1990

Flexible protein sequence patterns. A sensitive method to detect weak structural similarities.

The concept of a flexible protein sequence pattern is defined. In contrast to conventional pattern matching, template or sequence alignment methods, flexible patterns allow residue patterns typical of a complete protein fold to be developed in terms of residue positions (elements), separated by gaps of defined range. An efficient dynamic programming algorithm is presented to enable the best alignment(s) of a pattern with a sequence to be identified. The flexible pattern method is evaluated in detail by reference to the globin protein family, and by comparison to alignment techniques that exploit single sequence, multiple sequence and secondary structural information. A flexible pattern derived from seven globins aligned on structural criteria successfully discriminates all 345 globins from non-globins in the Protein Identification Resource database. Furthermore, a pattern that uses helical regions from just human alpha-haemoglobin identified 337 globins compared to 318 for the best non-pattern global alignment method. Patterns derived from successively fewer, yet more highly conserved positions in a structural alignment of seven globins show that as few as 38 residue positions (25 buried hydrophobic, 4 exposed and 9 others) may be used to uniquely identify the globin fold. The study suggests that flexible patterns gain discriminating power both by discarding regions known to vary within the protein family, and by defining gaps within specific ranges. Flexible patterns therefore provide a convenient and powerful bridge between regular expression pattern matching techniques and more conventional local and global sequence comparison algorithms.

Amino Acid Sequence↗
PubMed1990

rRNA gene restriction patterns of Leptospira: a molecular typing system.

A total of 67 serovar reference strains and 7 isolates belonging to the genus Leptospira were characterized by ribosomal ribonucleic acid (rRNA) gene restriction patterns. Fifty patterns were observed. Strains belonging to different genomic species always gave different patterns. However, genomic species were subdivided into several patterns. Forty-three serovars gave a specific pattern. Some serovars could not be separated by rRNA gene restriction patterns: strains of serovars icterohaemorrhagiae, copenhageni, lai, pyrogenes and jalna gave pattern 1; serovars birkini, mankarso and wolffi gave pattern 4; serovars canicola, gem, hebdomadis, pomona and hardjo (strain hardjoprajitno) gave pattern 12; serovars valbuzzi and zanoni gave pattern 14; serovars jonsis, malaya and sumneri gave pattern 16; serovars arborea, ballum, castellonis and kenya gave pattern 35; and serovars borincana and shermani gave pattern 43. These data provide the bases for a molecular typing system for the genus Leptospira.

Bacterial Typing Techniques↗
PubMed2005

Anatomical and histopathological correlates of the dermoscopic patterns seen in melanocytic nevi on the sole: a retrospective study.

BACKGROUND: Anatomical and histopathologic correlates of the unique dermoscopic patterns seen in melanocytic nevi on acral volar skin is yet to be clarified. OBJECTIVE: Our aim was to investigate the relation between the dermoscopic patterns and anatomical and histopathological characteristics of melanocytic nevi on the sole. METHODS: The precise locations of 298 melanocytic nevi on the sole from 278 patients were retrospectively investigated, with attention paid to each dermoscopic pattern. In addition, 35 nevi showing each typical dermoscopic pattern were excised and evaluated histopathologically. RESULTS: Melanocytic nevi showing the parallel furrow pattern or the fibrillar pattern were located on the portions of the sole with regular parallel skin markings and were not found on the arch areas of the foot. Moreover, a subtle but distinctive difference in the distribution was observed between nevi of the two patterns; the nevi with the fibrillar pattern showed a tendency for the sites directly pressed by the body's weight. Melanocytic nevi of the lattice-like pattern were mostly located on the arch areas. Histopathologically, irrespective of the dermoscopic patterns, nests of nevus cells were mainly located in the epidermal rete ridges underlying the surface sulci. In the nevi with a fibrillar pattern, the cornified layer showed a slanting arrangement, which is considered to be a histopathological background of the fibrillar pattern. CONCLUSION: Dermoscopic patterns seen in acral melanocytic nevi could be explained by the unique anatomical and histopathological characteristics of the acral skin.

Adolescent↗