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PubMed1979

The effects of hypercapnia, hypoxia, exercise and anxiety on the pattern of breathing in man.

1. The pattern of breathing, defined as the relations between tidal volume and inspiratory and expiratory times, was measured during the stimulation of breathing by carbon dioxide (hyperoxic rebreathing at rest) in twenty-seven healthy, young volunteers. 2. Most of the patterns (twenty) were divisible into two parts, for low (range 1) and high (range 2) tidal volumes. The relations were curved, inverse proportionalities for both inspiration and expiration in range 2, and for expiration in range 1. The relations for inspiration in range 1 were evenly divided between those with constant inspiratory times (type 1) and those with curved, inverse proportionalities (type 2). 3. In four volunteers, direct proportionalities predominated and the patterns were scattered (type 3). 4. Eight of the volunteers (four type 1, two type 2 and two type 3 patterns) repeated the measurements and one changed from a type 1 to a type 2 pattern. 5. Nine of the volunteers also rebreathed during resting hypoxia. Two altered their patterns, and the others had patterns which were superimposed upon those measured during hyperoxic rebreathing at rest. 6. Eighteen of the volunteers also rebreathed (hyperoxic) during light exercise (25 W). Five entrained their breathing frequency to the exercise rhythm and showed exercise patterns with constant inspiratory and expiratory times. The others had patterns which were extensions of those measured during hyperoxic rebreathing at rest. 7. The pattern of breathing in range 1 was measured by steady-state methods in a further ten volunteers at rest with their eyes closed and open, and during mental arithmetic. The pooled average pattern showed that the stress of mental arithmetic shortened both inspiratory and expiratory times, and changed a type 2 pattern into a type 1 pattern.

Adult↗
PubMed1995

Tar-dependent and -independent pattern formation by Salmonella typhimurium.

When Salmonella typhimurium cells were allowed to swarm on either a minimal or complex semisolid medium, patterns of cell aggregates were formed (depending on the thickness of the medium). No patterns were observed with nonchemotactic mutants. The patterns in a minimal medium were not formed by a mutant in the aspartate receptor for chemotaxis (Tar) or by wild-type cells in the presence of alpha-methyl-D,L-aspartate (an aspartate analog), thus resembling the patterns observed earlier in Escherichia coli (E. O. Budrene and H. C. Berg, Nature [London] 349:630-633, 1991) and S. typhimurium (E. O. Budrene and H. C. Berg, Abstracts of Conference II on Bacterial Locomotion and Signal Transduction, 1993). Distinctively, the patterns in a complex medium had a different morphology and, more importantly, were Tar independent. Furthermore, mutations in any one of the genes encoding the methyl-accepting chemotaxis receptors (tsr, tar, trg, or tcp) did not prevent the pattern formation. Addition of saturating concentrations of the ligands of these receptors to wild-type cells did not prevent the pattern formation as well. A tar tsr tcp triple mutant also formed the patterns. Similar results (no negative effect on pattern formation) were obtained with a ptsI mutant (defective in chemotaxis mediated by the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system [PTS]) and with addition of mannitol (a PTS ligand) to wild-type cells. It therefore appears that at least two different pathways are involved in the patterns formed by S. typhimurium: Tar dependent and Tar independent. Like the Tar-dependent patterns observed by Budrene and Berg, the Tar-independent patterns could be triggered by H(2)O(2), suggesting that both pathways of pattern formation may be triggered by oxidative stress.

Bacterial Proteins↗
PubMed1996

Discrimination of simulated texture patterns on the human hand.

1. Textures formed by periodic dot arrays are defined by the dot density, spacing, and angular orientation with respect to the direction of motion. In this report we evaluate the effects of the dot density (intensive cues) and arrangement (spatial cues) on the ability of human subjects to discriminate texture patterns scanned across an OPTACON tactile stimulator that selective stimulates rapidly adapting cutaneous mechanoreceptors. We compared dot arrays arranged on the index finger in specific patterns (horizontal, vertical, diamond, up diagonal, or down diagonal orientation) and spaced 4.8, 7.2, or 9.6 mm apart (high, medium, and low density) with the use of a two-alternative forced-choice protocol. 2. Textures are well discriminated when their elements are tightly spaced along one axis and widely spaced on all other axes. Humans distinguish textures that differ only in orientation with mean accuracy of 75% at low density and 65% at medium density, but discriminate high-density textures poorly (mean accuracy = 48%). Accuracy is related to the angular disparity between patterns, and to similarity of spacing and orientation along major and minor axes of the arrays. Vertical and horizontal patterns are more accurately distinguished than the oblique ones, and diamond arrays are the least well discriminated. Diagonal and diamond textures are often confounded, and the up and down diagonal patterns are confused with each other particularly as the texture density rises. The preference for the vertical and horizontal patterns may relate to an interaction between the orientation axis of the texture and its direction of motion across the skin. 3. Intensive cues provided by the total number of applied stimuli supplement the spatial cues inherent to the pattern orientation, because textures that differ in both spacing and orientation are discriminated better than those that differ only in orientation or spacing. Mean accuracy ranges from 96% for comparisons of high- and low-density textures, which differ in the total number of dots by a factor of 2, to 80% when medium-density patterns are compared with high- or low-density textures. 4. Textures that differ in density but not in orientation are less well discriminated than those of different orientation. For example, 82% of patterns that differ in both density and orientation are distinguished correctly in pairings of low- and medium-density textures, whereas those that differ only in density are discriminated correctly on 45% of trials. Subjects seem to use spatial rather than intensive cues when discriminating patterns of similar density, suggesting that the similarity of form (the spatial arrangement of the closely spaced dots) is more readily apparent than small differences in spacing along the axis of motion. 5. Subjects are most most successful in differentiating texture patterns when they are able to mentally picture the orientation and spacing of the pattern. We found a strong correlation between the subjects' ability to discriminate textures of a given spacing and their ability to identify the specific texture by matching it to the appropriate visual representation. Subjects are able to identify correctly all five orientations at low and medium densities, with mean accuracy of 76%, but recognize only the vertical arrays when high-density patterns are presented. The ability to image the textures is noteworthy, because subjects received no feedback about performance. 6. Spatial imaging of textures appears limited by the diameter of cutaneous receptive fields on the hand. We propose that the structural axis of a regular texture array results from perceptual linkage of adjacent elements along one principal axis by continuous bands of neural activity when their spacing is smaller than the receptive field diameter.(ABSTRACT TRUNCATED)

Adult↗
PubMed2002

Relationships among the metabolic patterns that correlate with mnemonic, visuospatial, and mood symptoms in Parkinson's disease.

OBJECTIVE: A multivariate analysis of baseline brain metabolism was used to investigate the relationships among pathophysiological mechanisms responsible for cognitive dysfunction and dysphoria in nondemented patients with Parkinson's disease. METHOD: Using [(18)F]fluorodeoxyglucose positron emission tomography and neuropsychological tests, the authors studied 15 nondemented patients who had Parkinson's disease without major depression (DSM-III-R). Their mean age was 59.2 years (SD=9.2), the mean rating of Parkinson's disease stage (Hoehn and Yahr scale) was 3.3 (SD=0.9), and all had Mini-Mental State Examination scores of 24 or higher. To identify specific regional patterns of brain metabolism associated with abnormal cognitive and mood functioning, the data were analyzed by using brain-behavior partial least squares. This multivariate voxel-based analysis allowed detection of significant topographic patterns of metabolic activity and quantification of the extent to which each topographic pattern correlated with scores on mnemonic, visuospatial, and dysphoric tests. RESULTS: Two significant, independent topographic patterns were identified. Pattern 1 included parieto-occipito-temporal and medial temporal brain regions, and pattern 2 included the lateral frontal and anterior limbic cortex. Patterns 1 and 2 exhibited a double dissociation in their behavioral correlates: pattern 1 correlated with both visuospatial and mnemonic functioning but not with dysphoria; pattern 2 correlated with dysphoria but not with the cognitive measures. CONCLUSIONS: The authors used the independence of topographic patterns and the size of correlations between topographic patterns and behavior to infer relationships among the pathophysiological processes responsible for the correlations. The finding that mildly abnormal mnemonic and visuospatial functioning correlated with the same topographic pattern suggests that a common pathophysiology underlies this marker of cognition in Parkinson's disease. By contrast, the independence of the two topographic patterns supports the notion that different mechanisms underlie cognitive and dysphoric symptoms in nondemented patients with Parkinson's disease.

Adult↗
PubMed2001

Serial EEG during human status epilepticus: evidence for PLED as an ictal pattern.

OBJECTIVE: To analyze the relationship between periodic lateralized epileptiform discharges (PLED) and status epilepticus (SE), to evaluate the relationship between mortality and periodic patterns, and to determine whether a stereotypic sequence of EEG patterns exists during human SE. METHODS: The authors performed a prospective clinical and electrographic study comprising 62 episodes of SE, 55 patients, and 254 ictal/postictal EEG recordings. Serial daily EEG were obtained in all cases. RESULTS: Partial SE was the predominant clinical type. Four distinct ictal EEG patterns were identified: intermittent EEG seizures (IES), merging EEG seizures (MES), continuous ictal discharges (CID), and periodic epileptiform discharges (PED) which could be lateralized (PLED) or bilateral (PBED). IES was the most common ictal pattern. In the same record, only one combination of ictal patterns was observed corresponding to an association of PLED or PBED and MES pattern. Serial EEG demonstrated that approximately one-third of SE resolved before the second EEG, another one-third persisted and maintained the same ictal pattern throughout the entire evolution, and the final one-third showed variable ictal EEG patterns. PLED were also unequivocally associated with epileptic seizures, and in some patients were the initial ictal pattern. CONCLUSION: PLED can be an ictal pattern; and, in contrast to previous observations, no stereotyped sequence of ictal EEG patterns was found. PLED/PBED were not a terminal ictal pattern in every case, and outcome was more related to age and etiology than to specific ictal EEG patterns.

Adolescent↗
PubMed1995

Breathing frequency and pattern are poor predictors of work of breathing in patients receiving pressure support ventilation.

OBJECTIVE: To evaluate the relationships between directly measured work of breathing (WOB) and variables of the breathing pattern commonly used at the bedside to infer WOB for intubated, spontaneously breathing patients treated with pressure support ventilation (PSV). DESIGN: In vivo measurements of the WOB were obtained on a consecutive series of adults. Breathing frequency (f), tidal volume (VT), the index of rapid, shallow breathing (f/V T), the duration of respiratory muscle contraction expressed as the ratio of inspiratory time over total respiratory cycle time (TI/TTOT), and a breathing pattern score (applied to approximately 50% of the patients) which ranks f, VT, sternocleidomastoid muscle activity, substernal retraction, and abdominal paradox on a scale were variables of the breathing pattern were also measured. The greater the breathing pattern score, the lower the WOB and vice versa. SETTING: Surgical ICUs in two university teaching hospitals. PATIENTS: Sixty-seven adults (42 men and 25 women, aged 20 to 78 years) who had acute respiratory failure from various etiologies were studied. All patients were breathing spontaneously receiving continuous positive airway pressure and PSV. INTERVENTIONS: Intraesophageal pressure (indirect measurement of intrapleural pressure) was measured with an esophageal balloon integrated into a nasogastric tube. VT was obtained by positioning a flow sensor between the "Y" piece of breathing circuit and the endotracheal tube. Data from these measurements were directed to a bedside respiratory monitor (Bicore; Allied Healthcare Products; Riverside, Calif) that calculates WOB using the Campbell diagram. Patients received PSV at levels deemed reasonable to unload the respiratory muscles. All measurements were obtained after 15 to 20 min at each level of PSV, averaged over 1 min, and then variables of the breathing pattern were regressed with directly measured values for WOB. RESULTS: All breathing pattern variables poorly predicted WOB as evidenced by the low values for the coefficients of determination (r2). Breathing frequency correlated positively with WOB (r = 0.47, p < 0.001) and predicted or explained only 22% (r2 = .22) of the variance in WOB. VT correlated negatively and f/VT and TI/TTOT each correlated positively with WOB. However, these variables predicted only 20 to 27% of the variance in WOB. The breathing pattern score correlated negatively with WOB and predicted only 43% of the variance in WOB. A prediction model taking all variables into consideration using multiple regression analysis predicted only 50% of the variance in WOB; thus, it too was a poor to moderate predictor of WOB. CONCLUSION: Our data reveal that WOB should be measured directly because variables of the breathing pattern commonly used at the bedside appear to be inaccurate and misleading inferences of the WOB. The clinical implication of these findings involves the traditional and empirical practice of titrating PSV based on the breathing pattern. We do not imply that the patient's breathing pattern should be ignored, nor undermine its importance, for it provides useful diagnostic information. It appears, however, that relying primarily on the breathing pattern alone does not provide enough information to accurately assess the respiratory muscle workload. Using the breathing pattern as the primary guideline for selecting a level of PSV may result in inappropriate respiratory muscle workloads. A more comprehensive strategy is to employ WOB measurements and the breathing pattern in a complementary manner when titrating PSV in critically ill patients.

Adult↗
PubMed2004

Pattern formation during T-cell adhesion.

T cells form intriguing patterns during adhesion to antigen-presenting cells. The patterns are composed of two types of domains, which either contain short TCR/MHCp receptor-ligand complexes or the longer LFA-1/ICAM-1 complexes. The final pattern consists of a central TCR/MHCp domain surrounded by a ring-shaped LFA-1/ICAM-1 domain, whereas the characteristic pattern formed at intermediate times is inverted with TCR/MHCp complexes at the periphery of the contact zone and LFA-1/ICAM-1 complexes in the center. Several mechanisms have been proposed to explain the T-cell pattern formation. Whereas biologists have emphasized the role of active cytoskeletal processes, previous theoretical studies suggest that the pattern evolution may be caused by spontaneous self-assembly processes alone. Some of these studies focus on circularly symmetric patterns and propose a pivot mechanism for the formation of the intermediate inverted pattern. Here, we present a statistical-mechanical model which includes thermal fluctuations and the full range of spatial patterns. We confirm the observation that the intermediate inverted pattern may be formed by spontaneous self-assembly. However, we find a different self-assembly mechanism in which numerous TCR/MHCp microdomains initially nucleate throughout the contact zone. The diffusion of free receptors and ligands into the contact zone subsequently leads to faster growth of peripheral TCR/MHCp microdomains and to a closed ring for sufficiently large TCR/MHCp concentrations. At smaller TCR/MHCp concentrations, we observe a second regime of pattern formation with characteristic multifocal intermediates, which resemble patterns observed during adhesion of immature T cells or thymozytes. In contrast to other theoretical models, we find that the final T-cell pattern with a central TCR/MHCp domain is only obtained in the presence of active cytoskeletal transport processes.

Animals↗
PubMed1996

Celiac disease: how common is jejunoileal fold pattern reversal found at small-bowel follow-through?

OBJECTIVE: Celiac disease, or nontropical sprue, is a cause of mucosal malabsorption. A decreased number of jejunal folds and an increased number of ileal folds (jejunoileal fold pattern reversal) found at small-bowel follow-through have been reported for patients with celiac disease. We asked three questions regarding jejunoileal fold pattern reversal found at small-bowel follow-through in patients with celiac disease. (1) How often is it present, either partially or completely? (2) How often is it associated with other findings of malabsorption? (3) How reliably can it be distinguished from the normal pattern? MATERIALS AND METHODS: Twenty-eight small-bowel follow-through examinations performed on 25 adult patients with celiac disease (confirmed by characteristic small-bowel biopsy and clinical response to a gluten-free diet) were reviewed retrospectively by two authors, who agreed by consensus on partial or complete jejunoileal fold pattern reversal and on other findings of malabsorption. Two methods were used to control for retrospective bias. (1) The prospective and retrospective readings of fold pattern reversal were compared for agreement. (2) The author who had not participated in the retrospective review was asked to distinguish, on the basis of the presence or absence of fold pattern reversal, 24 cases of celiac disease (all of which showed partial or complete fold pattern reversal on retrospective review) from 25 normal control cases (patients with diarrhea) (conformed by normal small-bowel biopsy). RESULTS: Partial or complete jejunoileal fold pattern reversal was identified retrospectively in 24 of the 28 small-bowel examinations (86%) performed on patients with celiac disease. One-half lacked other findings of malabsorption. The prospective and retrospective readings of fold pattern reversal agreed in 21 of the 28 examinations (75%). Forty-four of 49 examinations (90%) were correctly identified by the third author on the basis of fold pattern reversal. CONCLUSION: In patients with celiac disease, partial or complete jejunoileal fold pattern reversal discovered at small-bowel follow-through is common, is often not associated with other findings of malabsorption, and can be reliably distinguished from the normal pattern. Identification of jejunoileal fold pattern reversal found at small-bowel follow-through should prompt an appropriate clinical evaluation for celiac disease.

Adult↗
PubMed2001

MUC1 and cathepsin D expression in early colorectal carcinoma showing V type pit pattern.

The relation between MUC1, cathepsin D expression, and histologic features in early colorectal carcinomas (CRCs) with V type pit pattern was examined in 78 patients. We classified V type pit pattern into two grades (VA, VN) and we subclassified the VN type pit pattern into three subtypes (Grade A, B, and C) according to the degree of appearance of VN type pit pattern. At the tumor surface, the status of desmoplastic reaction and pit disorder or destruction were subclassified histologically into three grades (-, +, ++). MUC1 and cathepsin D expression were examined immunohistochemically at a superficial level and at the deepest part of the tumor invasion. MUC1 expression showed a significant correlation with high grade carcinoma, desmoplastic reaction (+) levels in VA type pit pattern (P<0.05), and high grade carcinoma, sm2 and sm3 lesions, desmoplastic reaction (+) and (++) levels, pit disorder or destruction (+) and (++) levels in VN type pit pattern (P<0.05). Cathepsin D expression had a significant correlation with m and sm1 lesions and desmoplastic reaction (-) levels in VN type pit pattern (P<0.05). In VA type pit pattern, a significant correlation between cathepsin D expression and histologic findings was absent. The incidence of MUC1 expression in VN.Grade B and C type pit pattern was significantly higher than that in VA and VN.Grade A type pit pattern (P<0.05). The incidence of cathepsin D expression in VA, VN.Grade A and B type pit pattern was significantly higher than that in VN.Grade C type pit pattern (P<0.05). MUC1 expression (+) or (++) levels at the deepest part of a tumor was identical to that (+) or (++) levels at the superficial part except for one case. Cathepsin D expression at the deepest part of a tumor differed from that at the superficial part. Desmoplastic reaction may be related to MUC1 and cathepsin D expression; however, pit disorder or destruction may be related to only MUC1 expression in V type pit pattern. MUC1 expression at the superficial part of a tumor may be related to expression at the deepest part; however, cathepsin D expression at the superficial part may not be related to expression at the deepest part in submucosal CRCs with V type lesions.

Cathepsin D↗
PubMedDate not supplied

Devascularization procedure and DSRS: a controlled randomized trial on selected haemodynamic portal flow pattern in schistosomal portal hypertension with variceal bleeding.

OBJECTIVES: The use of duplex studies for the portal tree has revolutionized the concepts of haemodynamic pathophysiology in the case of portal hypertensive bleeders. The identification of possible haemodynamic patterns in schistosomal bleeders, and the effects of devascularization procedure and distal lienorenal shunts on a selected haemodynamic pattern, are the aim of this work. PATIENTS AND METHODS: Patients (219) with schistosomal hepatic fibrosis and history of bleeding oesophageal varices were studied. The patency, diameter, velocity and flow volume/min in the portal and splenic veins were followed by coloured Duplex. Two matched groups (30 patients each) with the most commonly found haemodynamic pattern (splenic vein flow exceeding portal vein flow) were operated upon. Devascularization procedure was done for the first group (A) and distal splenorenal shunt for the second group (B). RESULTS: Coloured duplex assessment of portal circulation in schistosomal patients identified four haemodynamic patterns. Pattern I (approximately 59%); splenic vein flow exceeds the portal vein flow. Pattern II (approximately 28%); portal vein flow exceeds splenic vein flow. In both patterns, the portal flow was hepatopedal. Patterns III and IV (8% and 5%, respectively) were associated with hepatofugal flow. Splenic vein flow exceeds portal vein flow in pattern III and the reverse in pattern IV. Distal lienorenal shunts done for patients with haemodynamic pattern I was followed by a rebleeding rate of 3.3% while devascularization done for patients with the same pattern was followed by a rebleeding rate of 26.6%. Mild encephalopathy was detected in 10% of patients with distal lienorenal shunts and responded to dietary regulations. CONCLUSIONS: DSRS proved to be ideal for schistosomal patients with hepatopedal flow and splenic vein flow exceeding portal vein flow; since in addition to eliminating the high splenic flow out of portal circulation, it decreased the pressure in the gastroesophageal region. Other patterns with their frequencies and the suggested surgical procedures were also presented.

Adult↗
PubMed2003

Pattern of blood lead levels over working lifetime and neuropsychological performance.

The authors examined the impact on neuropsychological performance of past high lead exposure, followed by lower proximate lead exposure, in 2 groups of smelter workers selected on the basis of their patterns of blood lead levels (BLLs) over time. Prior to 1980 (past exposure), both groups had more than 90% of their BLLs > or = 40 microg/dl. During and subsequent to 1980 (proximate exposure), those subjects with more than 90% of their BLLs remaining at > or = 40 microg/dl were assigned to the high-high (H-H) pattern group (n = 40); whereas those with 90% of levels below 40 microg/dl were assigned to the high-low (H-L) pattern group (n = 40). Means (and standard deviations) for pre-1980 time-integrated blood lead (IBL) levels were similar for the H-H pattern [633.2 (202.2) microg/yr-dl] and the H-L pattern [556.5 (144.8) microg/yr x dl]; however, IBLs from 1980 on were significantly different [H-H pattern = 646.9 (58.70) microg/yr x dl and H-L pattern = 408.8 (46.37) microg/yr x dl; p < 0.0001]. Age, education, and years of employment were similar for both groups. Examination of 5 neuropsychological measures revealed that verbal memory was significantly better in the H-L pattern group than in the H-H group. Multivariate examination of the data showed that pattern of exposure contributed significantly to verbal memory performance, after adjustment for the covariates, current BLL, and IBL. A partial correlation analysis between verbal memory and IBL for past high exposure showed an association with H-H pattern, but none with H-L pattern. Pattern of BLLs over a working lifetime contributed unique variance to verbal memory. Absence of an association between past high lead exposure and verbal memory in the H-L pattern group suggests that reversibility of function may occur when proximate BLL is maintained below 40 microg/dl.

Female↗
PubMed2006

Longitudinal changes in dietary patterns during adult life.

Despite the growing interest in dietary patterns, there have been few longitudinal investigations. The objective of the present study was to extend an earlier method of dietary pattern assessment to longitudinal binary data and to assess changes in patterns over time and in relation to socio-demographic covariates. A prospective national cohort of 1265 participants completed a 5 d food diary at three time-points during their adult life (at age 36 years in 1982, 43 years in 1989 and 53 years in 1999). Factor analysis identified three dietary patterns for women (fruit, vegetables and dairy; ethnic foods and alcohol; meat, potatoes and sweet foods) and two patterns in men (ethnic foods and alcohol; mixed). Trends in dietary pattern scores were calculated using random effects models. Marked changes were found in scores for all patterns between 1989 and 1999, with only the meat, potatoes and sweet foods pattern in women recording a decline. In a multiple variable model that included the three time-points, socio-demographic variables and BMI time-dependent covariates, both non-manual social class and higher education level were also strongly associated with the consumption of more items from the ethnic foods and alcohol pattern and the mixed pattern for men (P < 0.0001) and the fruit, vegetables and dairy pattern and the ethnic foods and alcohol pattern for women (P < 0.01). In conclusion, longitudinal changes in dietary patterns and across socio-economic groups can assist with targeting public health initiatives by identifying stages during adult life when interventions to improve diet would be most beneficial to health.

Adult↗
PubMed1986

Transformation of a polygonal cellular pattern during sexual maturation of the avian oviduct epithelium: computer simulation.

A peculiar cellular pattern resembling a checkerboard has been observed on the luminal surface of the oviduct epithelium of an adult Japanese quail. The epithelium is a monolayer cell sheet and consists of two types of columnar cells, ciliated cells (C-cells) and gland cells (G-cells) assembled in alternating blocks. The pattern develops, during sexual maturation, from a kagome-like pattern (in which large C-cells are surrounded by small G-cells) characteristic of the immature oviduct. In the present paper, computer simulations of the pattern transformation from kagome to checkerboard were performed assuming a few properties of individual cells. The adult checkerboard-like pattern is not strictly rectangular, but is deformed toward a honeycomb pattern. In theoretical considerations the assumption that adhesion is stronger between unlike cells than between like cells formed an ideal checkerboard pattern, because all cell boundaries in it are edges along which unlike cells meet. On the other hand, a honeycomb pattern formed after assuming that the boundary length of the cellular pattern is minimized (caused by contraction of bundles of microfilaments running along lateral boundaries of the columnar epithelial cell while keeping contact between neighbouring cells). The actual checkerboard-like pattern was considered to be in a balanced state between the effects of (1) the strong adhesion between unlike cells, and (2) the boundary contraction. Using a computational analysis, this consideration enabled us to obtain a quantitative parameter value for the difference between cell adhesions of unlike cells and of like cells. C-cells divided once during the kagome-checkerboard transformation, while G-cells did not divide. We performed computer simulations starting with the kagome pattern in which all C-cells divided once. The computer program of the boundary shortening procedure we used involved the quantitative parameter value for differential cell adhesion obtained as described above. A checkerboard pattern was successfully generated in the simulation. It is concluded that the strong adhesion between unlike cells and the boundary shortening have important roles in formation and maintenance of the kagome and checkerboard patterns of the avian oviduct epithelium.

Animals↗
PubMed1996

[Decreased incidence of peripheral nuclear staining pattern by indirect immunofluorescent antibody technique using HEp-2 cells].

The immunofluorescence technique using HEp-2 cells is widely used for the detection of antinuclear antibodies in sera of patients with connective tissue diseases. Among different patterns of nuclear staining the incidence of peripheral pattern which is mainly produced by anti double-stranded DNA antibodies has been markedly decreased after using HEp-2 cells as nuclear substrates. Thirty-five sera in interphase cells and 44 sera in metaphase cells showed peripheral pattern at 1:1 serum dilution from 70 patients with various connective tissue diseases including 46 systemic lupus erythematosus. Metaphase cells nuclei were more sensitive to peripheral pattern than those in interphase cells. Assuming that the incidence of peripheral pattern at 1:1 dilution was 100%, the incidence of peripheral pattern at 1:20 serum dilution dropped into 57.1% in interphase cells and 38.6% in metaphase cells, respectively. The incidence of peripheral pattern at 1:40 dilution dropped into 65.7% in interphase cells and 56.8% in metaphase cells, respectively. Mean value and incidence of anti double-stranded DNA antibodies detected by RIA were significantly higher in sera with peripheral pattern than in sera without peripheral pattern. However, there were some sera which showed peripheral pattern without anti double-stranded DNA antibodies, or there are a few sera which had anti double-stranded DNA antibodies without peripheral pattern. The drop of the incidence of peripheral pattern might be due to interference effect of multiple different antinuclear antibodies. It is necessary to detect anti double-stranded DNA antibodies directly by radioimmunoassay or enzyme-linked immunosorbant assay if occurrence of anti double-stranded DNA antibodies is clinically suspected without peripheral immunofluorescent pattern.

Antibodies, Antinuclear↗
PubMed1997

Detection of chromosomal anomalies and c-myc gene amplification in the cribriform pattern of prostatic intraepithelial neoplasia and carcinoma by fluorescence in situ hybridization.

Grading of the cribriform pattern of prostate cancer is controversial, and the genetic changes are largely unknown. Furthermore, the pathogenetic relationship between the cribriform pattern of high-grade prostatic intraepithelial neoplasia (PIN) and cribriform carcinoma is poorly understood. We used fluorescence in situ hybridization with centromere-specific probes for chromosomes 7, 8, 10, 12, and Y and a region-specific probe for c-myc to evaluate genetic changes in matched foci of high-grade PIN (48 foci) and prostatic carcinoma (71 foci) in 25 whole-mount radical prostatectomy specimens from patients with metastatic cancer. These cases included 10 foci of cribriform PIN and 10 foci of cribriform cancer. Numeric chromosomal anomalies were found in 67 and 68% of the high-grade PIN and carcinoma foci, respectively. Extra copies of the c-myc gene were identified in 52 and 44% of the high-grade PIN and carcinoma foci, respectively. The cribriform pattern of cancer had a higher percentage of foci with gain of chromosomes 7, 12, and Y, loss of chromosome 8, and extra copies of c-myc gene than other Gleason Primary Patterns 3 and 4; there was no difference, however, for all paired comparisons of genetic changes between the cribriform pattern of cancer and Gleason Primary Pattern 5 cancer. Cribriform PIN and cribriform cancer generally exhibited similar anomalies, although the percentage of foci with gain of chromosomes 10 and 12 was higher in cribriform cancer. Our results indicate that the cribriform pattern of prostate cancer shares genetic changes with Gleason Primary Pattern 5 and that both contain more genetic changes than the cribriform pattern of PIN. These findings suggest that the cribriform pattern of prostate cancer has biologic similarity with Gleason Pattern 5 carcinoma and that the cribriform pattern of PIN is closely associated with the cribriform pattern of prostatic carcinoma.

Adenocarcinoma↗
PubMed2004

Cellular patterns in the inner retina of adult zebrafish: quantitative analyses and a computational model of their formation.

The mechanisms that control cellular pattern formation in the growing vertebrate central nervous system are poorly understood. In an effort to reveal mechanistic rules of cellular pattern formation in the central nervous system, quantitative spatial analysis and computational modeling techniques were applied to cellular patterns in the inner retina of the adult zebrafish. All the analyzed cell types were arrayed in nonrandom patterns tending toward regularity; specifically, they were locally anticlustered. Over relatively large spatial scales, only one cell type exhibited consistent evidence for pattern regularity, suggesting that cellular pattern formation in the inner retina is dominated by local anticlustering mechanisms. Cross-correlation analyses revealed independence between the patterns of different cell types, suggesting that cellular pattern formation may involve multiple, independent, homotypic anticlustering mechanisms. A computational model of cellular pattern formation in the growing zebrafish retina was developed, which featured an inhibitory, homotypic signaling mechanism, arising from differentiated cells, that controlled the spatial profile of cell fate decisions. By adjusting the spatial profile of this decaying-exponential signal, the model provided good estimates of all the cellular patterns that were observed in vivo, as objectively judged by quantitative spatial pattern analyses. The results support the hypothesis that cellular pattern formation in the inner retina of zebrafish is dominated by a set of anticlustering mechanisms that may control events at, or near, the spatiotemporal point of cell fate decision.

Animals↗
PubMed1980

A template matching model for pattern recognition: self-organization of templates and template matching by a disinhibitory neural network.

A template matching model for pattern recognition is proposed. By following a previously-proposed algorithm for synpatic modification (Hirai, 1980), the template of a stimulus pattern is self-organized as a spatial distribution pattern of matured synapses on the cells receiving modifiable synapses. Template matching is perfomed by the disinhibitory neural network cascaded beyond the neural layer composed of the cells receiving the modifiable synapses. The performance of the model has been simulated on a digital computer. After repetitive presentations of a stimulus pattern, a cell receiving the modifiable synapses comes to have the template of that pattern. And the cell in the latter layer of the disinhibitory neural network that receives the disinhibitory input from that cell becomes selectively sensitive to that pattern. Learning patterns are not restricted by previously learned ones. They can be subset or superset patterns of the ones previously learned. If an unknown pattern is presented to the model, no cell beyond the disinhibitory neural network will respond. However, if previously learned patterns are embedded in that pattern, the cells which have the templates of those patterns respond and are assumed to transmit the information to higher center. The computer simulation also show that the model can organize a clean template under a noisy environment.

Animals↗
PubMedDate not supplied

Acquisition of a unique cue in positive and negative patterning?

Forty college students received a classical differential conditioning procedure involving both positive and negative patterning, each of these being associated with a different pair of stimuli. In positive patterning, elemental stimuli, A and B, were presented without an unconditioned stimulus while their compound, AB, was paired with electric shock. In negative patterning, elemental stimuli, C and D, were paired with shock while their compound, CD, remained unpaired. Thirty of these subjects then received a negative patterning transfer test on new stimuli, while ten subjects received a positive patterning transfer test. First interval response (FIR) and second interval response (SIR) were measured. During initial acquisition, positive patterning occurred in both dependent measures, but negative patterning was present only in the SIR. The transfer tests showed almost significant transfer of positive patterning in FIR and SIR. Negative patterning showed significant transfer neither in FIR nor SIR. It was concluded that, although elementary models of conditioning can explain positive patterning on the basis of summation of excitation from the elements to the compound, the occurrence of negative patterning in the SIR and the almost significant transfer of positive patterning in FIR and SIR appear to require the additional assumption of a unique cue.

Adult↗