Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “patterning”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1989

Discrimination of opposite directions measured with stroboscopically illuminated random-dot patterns.

The aim of the present experiments was to investigate the maximum displacement over which coherent motion can be perceived (Dmax) for a stroboscopically illuminated moving random-dot pattern, both as a function of the size of the pattern and as a function of the spatial-frequency content. Perception of coherent motion was defined operationally as the ability to discriminate opposite directions. The maximum velocity (Vmax) for which the observer could discriminate the direction of motion for a given strobe rate was obtained by using a forced-choice staircase procedure. Vmax was measured as a function of the strobe rate for four different sizes of the pattern. For each pattern size Vmax was limited by the spatial asynchrony between the flashes (Dmax). For a given size of the pattern, Dmax did not depend on the temporal asynchronies tested (10-100 msec). Dmax values were increased with the size of the pattern. Bandpass rectangular filtering was used to change the spatial-frequency content of the pattern. There was a gradual increase in Dmax as the spatial-frequency content shifted to low spatial frequencies. Interestingly, the Dmax that was obtained with the unfiltered pattern was larger than that obtained with the high-pass pattern but also smaller than that obtained with the low-pass pattern. The present results are in agreement with results obtained with a two-frame display. Dmax is not a fixed value: it depends on the size of the pattern as well on the spatial-frequency content.(ABSTRACT TRUNCATED AT 250 WORDS)

Discrimination, Psychological↗
PubMed1997

Patterns of cognitive development in very low birth weight children during the first six years of life.

BACKGROUND: Cognitive development in very low birth weight (VLBW, < or = 1500 g) infants typically has been reported based on mean endpoints in cross-sectional studies. These overall group means mask individual patterns of cognitive development. Given the heterogeneity of VLBW infants, it is important to identify individual patterns of development and the factors associated with the different patterns. OBJECTIVE: We sought to determine individual patterns of cognitive development over the first 6 years in VLBW children and to examine the relative influence of selected biomedical and sociodemographic factors on these patterns. METHOD: VLBW infants (N = 203) were followed from birth to six years. Cognitive scores were obtained at four yearly intervals, and biomedical and social data were obtained beginning with the neonatal period. Cluster analysis was used to identify individual patterns of cognitive development. RESULTS: Five developmental patterns were identified: average-stable (13% of the sample); average-declined to low average (24% of the sample); average-declined to below average (43% of the sample); very low-increased to low average (8% of the sample); and very low-stable (12% of the sample). The patterns could be differentiated by several biomedical factors, including birth weight, gestational age, neonatal health, and 1-year assessments of neurological status and head circumference, as well as by level of maternal education. In particular, abnormal neurological status at 1 year was associated with a pattern of very low stable scores, and a suspicious status was associated with a pattern of improving cognitive development. Maternal education was influential among children born at the upper end of the VLBW range, who had a more favorable set of biomedical factors. CONCLUSIONS: Biomedical factors are of major importance for the cognitive development of VLBW infants, and their influence increases as birth weight declines. Differences in neurological integrity at 1 year were an important indicator of different patterns of cognitive development, especially for infants at the lower end of the VLBW range.

Child Development↗
PubMed2005

Morphological comparison of pupal wing cuticle patterns in butterflies.

Butterfly wing color-patterns are determined in the prospective wing tissues during the late larval and early pupal stages. To study the cellular differentiation process of wings, morphological knowledge on pupal wings is prerequisite. Here we systematically examined morphological patterns of the pupal wing cuticular surface in a wide variety of nymphalid butterflies in relation to adult color-patterns. Several kinds of pupal wing patterns corresponding to particular adult color-pattern elements were widely observed in many species. Especially noteworthy were the pupal "focal" spots corresponding to the adult border ocelli system, which were detected in many species of Nymphalinae, Apaturinae, Argynninae, Satyrinae, and Danainae. Striped patterns on the pupal wing cuticle seen in some species of Limenitinae, Ariadnae, and Marpesiinae directly corresponded to those of the adult wings. In Vanessa cardui, eyespot-like pattern elements were tentatively produced during development in the wing tissue underneath the pupal spots and subsequently erased, suggesting a mechanism for producing novel color-patterns in the course of development and evolution. The pupal focal spots reasonably correlated with the adult eyespots in size in Precis orithya and Ypthima argus. We physically damaged the pupal focal spots and their corresponding cells underneath in these species, which abolished or inhibited the formation of the adult eyespots. Taken together, our results clarified that pupal cuticle patterns were often indicative of the adult color-patterns and apparently reflect molecular activity of organizing centers for the adult color-pattern formation at least in nymphalid butterflies.

Animals↗
PubMed1999

An ethogram of body patterning behavior in the biomedically and commercially valuable squid Loligo pealei off Cape Cod, Massachusetts.

Squids have a wide repertoire of body patterns; these patterns contain visual signals assembled from a highly diverse inventory of chromatic, postural, and locomotor components. The chromatic components reflect the activity of dermal chromatophore organs that, like the postural and locomotor muscles, are controlled directly from the central nervous system. Because a thorough knowledge of body patterns is fundamental to an understanding of squid behavior, we have compiled and described an ethogram (a catalog of body patterns and associated behaviors) for Loligo pealei. Observations of this species were made over a period of three years (> or = 440 h) and under a variety of behavioral circumstances. The natural behavior of the squid was filmed on spawning grounds off Cape Cod (northwestern Atlantic), and behavioral trials in the laboratory were run in large tanks. The body pattern components--34 chromatic (including 4 polarization components), 5 postural, and 12 locomotor--are each described in detail. Eleven of the most common body patterns are also described. Four of them are chronic, or long-lasting, patterns for crypsis; an example is Banded Bottom Sitting, which produces disruptive coloration against the substrate. The remaining seven patterns are acute; they are mostly used in intraspecific communication among spawning squids. Two of these acute patterns--Lateral Display and Mate Guarding Pattern--are used during agonistic bouts and mate guarding; they are visually bright and conspicuous, which may subject the squids to predation; but we hypothesize that schooling and diurnal activity may offset the disadvantage presented by increased visibility to predators. The rapid changeability and the diversity of body patterns used for crypsis and communication are discussed in the context of the behavioral ecology of this species.

Animal Communication↗
PubMed2001

Incidence of the endothelin receptor B mutation that causes lethal white foal syndrome in white-patterned horses.

OBJECTIVE: To determine incidence of the Ile118Lys endothelin receptor B (EDNRB) mutation responsible for overo lethal white syndrome (OLWS) and its association with specific types of white patterning. ANIMALS: 945 horses of white-patterned bloodlines and 55 solid-colored horses of other breeds. PROCEDURE: Horses were genotyped by use of allele-specific polymerase chain reaction to determine incidence of the Ile118Lys EDNRB mutation. RESULTS: Genotypes detected were homozygous Ile118, homozygous Lys118, and heterozygous. All foals with OLWS were homozygous for the Ile118Lys EDNRB mutation, and adults that were homozygous were not found. White patterning was strongly associated with EDNRB genotype. Color patterns with highest incidence (> 94%) of heterozygotes were frame overo, highly white calico overo, and frame blend overo. White-patterned bloodlines with lowest incidence of heterozygotes (< 21 %) were tobiano, sabino, minimally white calico overo, splashed white overo, nonframe blend overo, and breeding-stock solid. The mutation was not detected in solid-colored horses from breeds without white patterning. CONCLUSIONS AND CLINICAL RELEVANCE: In homozygotes, the Ile118Lys EDNRB mutation causes OLWS. In heterozygotes, the mutation is usually responsible for a frame overo phenotype. The frame pattern can be combined with other white patterns, making accurate estimation of EDNRB genotype by visual inspection difficult. Wide range of incidence of heterozygotes in various subtypes of white-patterned horses indicates different genetic control of these color patterns. Determination of EDNRB genotype by use of a DNA-based test is the only way to determine with certainty whether white-patterned horses can produce a foal affected with OLWS.

Amino Acid Substitution↗
PubMed2003

Dietary patterns and further survival in Japanese centenarians.

We have previously reported that centenarians (persons > or = 100 y old) in Tokyo prefer dairy products. Dietary preferences may be associated with longevity. The aim of the present study was to investigate the relationship between dietary patterns and further survival in centenarians. During 1992-1999, we examined the dietary practices of 104 centenarians (29 men and 75 women; mean age, 100.3 +/- 0.9 y) who lived in the Tokyo metropolitan area. Dietary patterns were classified by kappa-means cluster analysis. As clinical co-variables, we considered activities of daily living, cognitive function, nutritional status, presence of important disease, gender, and age at the time of the initial survey. Survival data were recorded yearly until 2001, and then tested with Kaplan-Meier analysis and the log rank statistic. Four dietary patterns were identified: a pattern preferring vegetables (n = 33), a pattern preferring dairy products (n = 26), a pattern preferring beverages (n = 10), and a pattern preferring cereals (n = 35). No clinical variables differed between the four dietary patterns. In 2001, 28 centenarians were still alive. The survival rate for those preferring dairy products was the highest of the four dietary patterns; in particular, being significantly higher than the pattern preferring beverages (p = 0.048). A dietary pattern preferring dairy products was associated with increased survival in Tokyo-area centenarians.

Activities of Daily Living↗
PubMed2006

Prospective study of differential diagnosis of hepatic tumors by pattern-based classification of contrast-enhanced sonography.

AIM: To prospectively evaluate the usefulness of a pattern-based classification of contrast-enhanced sonographic findings for differential diagnosis of hepatic tumors. METHODS: We evaluated the enhancement pattern of the contrast-enhanced sonography images in 586 patients with 586 hepatic lesions, consisting of 383 hepatocellular carcinomas, 89 metastases, and 114 hemangiomas. After injecting a galactose-palmitic acid contrast agent, lesions were scanned by contrast-enhanced harmonic gray-scale sonography in three phases: arterial, portal, and late. The enhancement patterns of the initial 303 lesions were classified retrospectively, and multiple logistic regression analysis was used to identify enhancement patterns that allowed differentiation between hepatic tumors. We then used the pattern-based classification of enhancement we had retrospectively devised to prospectively diagnose 283 liver tumors. RESULTS: Seven enhancement patterns were found to be significant predictors of different hepatic tumors. The presence of homogeneous or heterogeneous enhancement both in the arterial and portal phase was the typical enhancement pattern for hepatocellular carcinoma, while the presence of peritumoral vessels in the arterial phase and ring enhancement or a perfusion defect in the portal phase was the typical enhancement pattern for metastases, and the presence of peripheral nodular enhancement both in the arterial and portal phase was the typical enhancement pattern for hemangioma. The sensitivity, specificity, and accuracy of prospective diagnosis based on the combinations of enhancement patterns, respectively, were 93.2%, 96.2%, and 94.0% for hepatocellular carcinoma, 87.9%, 99.6%, and 98.2% for metastasis, and 95.6%, 94.1%, and 94.3% for hemangioma. CONCLUSION: The pattern-based classification of the contrast-enhanced sonographic findings is useful for differentiating among hepatic tumors.

Aged↗
PubMed2000

Processing of sequential tactile patterns: effects of a neutral stimulus.

The perception of a target pattern may be interfered with by the presentation of a nontarget pattern in close temporal and spatial proximity with it. The results from previous studies suggested that much of this interference is the result not of masking but of response competition, subjects responding with the nontarget instead of the target. Using a 4-to-2 paradigm in which four target patterns are mapped onto two responses, it was shown that neutral patterns (i.e., patterns with no responses associated with them) produce considerable interference. The amount of interference is less than that produced by patterns associated with incorrect responses but greater than that produced by patterns associated with correct responses. The amount of interference produced by neutral patterns did not vary as a function of the form of the neutral pattern (Experiments 1 and 2); however, the amount of interference did depend on the degree and nature of the similarity between the neutral and target patterns (Experiments 3 and 4). The results indicate that recent studies have underestimated the amount of interference due to masking and overestimated the amount due to response competition. Response competition may either hinder or help target categorization depending on the nontarget pattern.

Adolescent↗
PubMed2005

Distinguishing fibrovascular septa from vasculogenic mimicry patterns.

CONTEXT: Molecular analyses indicate that periodic acid-Schiff (PAS)-positive (laminin-rich) patterns in melanomas are generated by invasive tumor cells by vasculogenic mimicry. Some observers, however, consider these patterns to be fibrovascular septa, generated by a stromal host response. OBJECTIVE: To delineate differences between vasculogenic mimicry patterns and fibrovascular septa in primary uveal melanomas. DESIGN: Frequency distributions, associations with outcome, and thicknesses of trichrome-positive and PAS-positive looping patterns were determined in 234 primary uveal melanomas. Sequential sections of 13 additional primary uveal melanomas that contained PAS-positive/trichrome-negative looping patterns were stained for type I and type IV collagens, laminin, and fibronectin. Real-time quantitative polymerase chain reaction was performed on RNA from cultured uveal melanoma cells for the expression of COL1A1, COL4A2, and fibronectin. RESULTS: Trichrome-positive loops were encountered less frequently than PAS-positive loops (10% vs 56%, respectively). Death from metastatic melanoma was strongly associated with PAS-positive (P < .001) but not with trichrome-positive (P = .57) loops. Trichrome-positive loops were significantly thicker than PAS-positive loops (P < .001). The PAS-positive patterns stained positive for laminin, type I and type IV collagens, and fibronectin. Type I collagen was detected within melanoma cells and focally within some PAS-positive patterns. Real-time quantitative polymerase chain reaction revealed 3-fold, 25-fold, and 97-fold increases, respectively, in expression of COL4A2, fibronectin, and COL1A1 by invasive pattern-forming primary melanoma cells compared with poorly invasive non-pattern-forming cells. CONCLUSIONS: Fibrovascular septa are rare and prognostically insignificant in uveal melanomas, whereas vasculogenic mimicry patterns are associated with increased mortality. Type I collagen, seen focally in some vasculogenic mimicry patterns, may be synthesized by tumor cells, independent of a host stromal response.

Azo Compounds↗
PubMed1999

Various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke.

BACKGROUND AND PURPOSE: Various clinical subtypes of patients presenting with sudden-onset ischemic stroke have been recognized, but classification of those types is not simple. We identified various patterns of perfusion-weighted MR imaging and MR angiographic findings in hyperacute ischemic stroke with relation to clinical outcomes. METHODS: Twelve patients with symptoms of acute ischemic stroke due to middle cerebral artery occlusion underwent perfusion-weighted MR imaging and MR angiography within 6 hours after the onset of symptoms. Perfusion-weighted imaging was performed with a conventional dynamic contrast-enhanced T2*-weighted sequence, and cerebral blood volume (CBV) maps were then created. CBV maps and MR angiographic findings were compared with 99mTc-HMPAO brain SPECT scans, short-term outcomes, and follow-up imaging findings. RESULTS: The combined CBV and MR angiographic findings were classified into three patterns: arterial occlusion and decreased CBV (n = 8), arterial occlusion and increased CBV (n = 2), and no arterial occlusion and normal CBV (n = 2). These three patterns were strongly related to SPECT findings, short-term outcomes, and follow-up imaging findings. Perfusion on SPECT decreased markedly in the affected regions in all patients with the first pattern, decreased slightly in the second pattern, and was normal in the third pattern. Symptoms were not significantly changed at 24 hours after onset in any of the patients with the first pattern, but resolved completely in all patients with the latter two patterns. Follow-up imaging showed large infarctions in all patients with the first pattern. Initially, no infarction was seen in the second pattern, but watershed infarction developed later in one of these patients. CONCLUSION: Hyperacute ischemic stroke may be differentiated into three imaging patterns with different clinical outcomes. The combined use of perfusion-weighted MR imaging and MR angiography may play a substantial role in guiding the choice of treatment of this disease.

Acute Disease↗
PubMed2002

Histopathological approach to patterns of interstitial pneumonia in patient with connective tissue disorders.

It is well established that some patients with connective tissue disorders will suffer from pulmonary disease at some stage in their disease progression. This article concentrates on the interstitial pneumonias, seen in association with most types of connective tissue disorder, particularly in the ligh of non-specific interstitial pneumonia (NSIP) being recognised as a distinct histological pattern. Most published articles on this subject precede recognition of NSIP and, as such, the relative incidence of patterns of interstitial pneumonia, as defined by the International Consensus Classification Committee for Interstitial Lung Disease (ICCILD), as well as the clinical and prognostic significance of these patterns is undergoing further scrutiny. In this review, the recognised histological patterns, namely usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), diffuse alveolar damage (DAD), organising pneumonia (OP), reactive pulmonary lymphoid hyperplasia, desquamative interstitial pneumonia (DIP) and respiratory bronchiolitis-associated interstitial lung disease (RBILD) are reviewed systematically in relation to the various subgroups of connective tissue disorders. As yet, there are few published studies, but current evidence suggests that many cases previously classified as fibrosing alveolitis are likely to show a pattern of NSIP rather than UIP, particularly in relation to systemic sclerosis. The histological pattern of usual interstitial pneumonia, the most frequently seen pattern in biopsies from patients with idiopathic pulmonary fibrosis/cryptogenic fibrosing alveolitis, appears to be comparatively rare. Furthermore, any biopsy showing a combination of histological patterns, a pattern of non-specific interstitial pneumonia or a pattern of lymphoid interstitial pneumonia/follicular bronchiolitis should be thoroughly investigated for a background connective tissue disorder, if previously unsuspected. Finally, the recently published prognostic data relating to these histological patterns in idiopathic disease should not be extrapolated to patients with connective tissue disorders.

Connective Tissue Diseases↗
PubMedDate not supplied

An examination of regional migration patterns in Mexico: new and old Mexican regions.

This paper examines Mexican regional patterns. Different regional definitions are utilized to examine in-/out-migration patterns in 4 different periods: 1) 1979-1980, 2) 1975-1979, 3) prior to 1975, and 4) lifetime. 5 regional definitions previously used to delineate state level Mexican regions were compared to new regions by a maximum likelihood clustering technique. Previously defined regions do not compare with the empirically delineated regions developed by the cluster analysis. A cluster analysis of in-/out-migration patterns suggests the following: 1) distinct in-/out-migration patterns for both short- and long-term migration patterns, 2) a central region consisting of Mexico and the Federal District having its own distinct regional characteristics for both in-/out-migration patterns, particularly intraregional migration among those 2 states exceeds any other interregional migration patterns, and 3) the unique role played by Jalisco in mediating long-term inflows prior to 1975, and since 1975, out-migration from the same state. Previous research rarely identified the Central region consisting of Mexico and the Federal District. Using net migration for interregional migration analysis may possibly be misleading since immigration and out-migration phenomena show distinct patterns of geographic mobility at the state level, and such regional differences are consistent for the 4 migration periods. A careful analysis accounting for both distinct migration patterns in the Central region and different patterns in in-/out-migration are necessary to obtain an understanding of regional migration patterns in Mexico.

Americas↗
PubMed2003

V-pattern esotropia: a review; and a study of the outcome after bilateral recession of the inferior oblique muscle: a retrospective study of 78 consecutive patients.

BACKGROUND: A V-pattern esotropia with bilateral overaction of the inferior oblique (IO) is a common finding. The clinical characteristics of this condition in a large series are not available. Also, data is lacking about the surgical outcome of graded bilateral inferior oblique recessions. Lastly, it is not known whether patients with a V pattern below 15 prism diopters (pd) should have IO weakening when horizontal eye muscle surgery is to be performed. SUBJECTS AND METHODS: Seventy-eight consecutive patients without complicating factors were fully evaluated and submitted to bilateral graded recessions of the IO. In Group 1, 59 patients had a V pattern of 15 pd or more; 55 were also operated for a horizontal imbalance. In Group 2, 19 patients in whom a horizontal surgery was required and who also had a V pattern of less than 15 pd, also had a bilateral graded recession of the IO performed. RESULTS: Preoperative findings: In Group 1, the distribution of V patterns showed 88.1% in the range 15 to 35 pd. A bilateral overaction of the IO, a bilateral underaction of the superior oblique (SO), and elevation in adduction OU were present in 62.7% of the patients. A vertical imbalance was observed in 20.3%. In Group 2, a bilateral overaction of the IO, a bilateral underaction of the SO, and elevation in adduction OU were noticed in 42.1% of the patients. A vertical deviation was seen in 26.3%. After surgery, in Group 1, 83% had less than 15 pd of V pattern or less than 10 pd of A pattern. Surgery reduced a presurgical vertical imbalance, but created a vertical deviation in some cases devoid of hypertropia before surgery. After surgery in Group 2, a full correction or undercorrection was obtained in 63.1% of the patients and an overcorrection to an A pattern in 21.0% Surgery was also prone to induce a vertical deviation. Binocularity: There was an improvement of the fusional status with surgery, (ascertained with the Worth Four Dot Test and major amblyoscope measurement), in patients of both Groups 1 and 2. CONCLUSION: In V-pattern esotropia cases of 15 pd or more the vast majority were in the range 15-35 pd. Overaction of both IO, underaction of both SO, and elevation in adduction OU constituted a triad of co-occurrent signs present in a significant number of patients. A vertical imbalance was detected in 1/5 of the cases. A good outcome (collapse of the V pattern) was obtained with bilateral graded recession of the IO, but this surgery can create a vertical imbalance. In cases of V pattern less than 15 pd, and requiring horizontal surgery, weakening of both IO's can be advised.

Child↗
PubMed1989

Effect of after-discharge EEG patterns on performance and latency of the conditioned avoidance response in hippocampally kindled cats.

The relation between different EEG after-discharge patterns and memory retrieval of the conditioned avoidance response was studied in 8 hippocampally kindled cats. The after-discharge patterns were classified into 5 basic EEG types. The relation was analyzed in three different situations: A, at the conditioning stimulation onset, B, at the conditioning stimulus termination, and C, when conditioning stimulus onset and termination were studied within the same type of EEG pattern of after-discharge. The moment of presentation of the conditioning stimulus was determined by the type of EEG after-discharge pattern. Significant relation was observed between reflex performance and type II and III EEG AD types. The type II (4.5-12/s spiking activity) was associated with a greater proportion of positive responses if presented on the uniform background of EEG after-discharge patterns. During the type III pattern (EEG dysrhythmia), there were more negative than positive responses in all the three experimental situations, especially if the type III EEG pattern was observed at the time of conditioned stimulus termination. The latency of reflex performance measured in the experimental condition C (the same pattern of EEG during conditioning stimulus onset and termination) was longer during the type II EEG pattern of after-discharges than the latencies found during type III EEG activity and in the control group. During type III pattern associated with greatest proportion of response failures there was, however, no increase of reflex latencies. The results suggest differential effect of different EEG after-discharge patterns on memory retrieval of the well established conditioned avoidance response in cats.

Animals↗
PubMed1995

Cytokeratin patterns of liver carcinomas induced by diethylnitrosamine in monkeys.

BACKGROUND: Although the general conception is that hepatocyte- and bile duct-specific cytokeratin (CK) patterns are maintained throughout the neoplastic process, there is an increasing number of reports showing deviation from the rule. CK patterns have been found to be similar across species barriers, so it could be expected that studying the CK patterns of experimentally induced liver tumors may contribute to the elucidation of these controversies. EXPERIMENTAL DESIGN: A CK immunohistochemical study was carried out on histologic sections from hepatocellular carcinomas (HCCs) and preneoplastic lesions from 118 monkeys chronically dosed with diethylnitrosamine (DEN), using mAbs to CK 8, CK 18, CK 7, and CK 19. RESULTS: Normal monkey hepatocytes differed from human hepatocytes by displaying CK 19 in addition to the CK 8/CK 18 pairs, whereas the CK pattern of the bile duct epithelial cells was identical in monkey and human liver. In association with DEN-induced hepatocarcinogenesis, heterogeneity was observed in the CK expression, both in the HCCs and nontumorous parts of the livers. The majority of the HCC cases displayed one of the three CKs normally present in monkey hepatocytes, whereas positive expression of all three CKs (CK 8, CK 18, CK 19) and negative CK 7 was preserved in only 19.5% of the HCC cases. A so-called mixed staining pattern (negative and positive CK staining within the same tumor) was observed in approximately one-fourth of the cases. There was no correlation between the preservation of the hepatocyte-specific CK pattern and the degree of differentiation, tumor grade, or DNA ploidy of the HCCs. In approximately 10% of the primary tumors, CK 7 was expressed in the entire parenchymal cell compartment of the HCC nodules, whereas it was present in a mixed staining pattern in more than half of the cases. In lung metastases, CK 7 was less common, only expressed in approximately one-fourth of the cases. Alterations in the CK patterns were observed in the nonneoplastic hepatocytes of the tumor-bearing monkeys. These included mixed staining patterns in which the CKs appeared as positive and negative regenerating nodules side-by-side. As was observed in the HCCs, CK 7 was more commonly expressed in the nonneoplastic parenchyma in the form of mixed staining pattern than the other three CKs. Moreover, CK 7-negative HCCs occurred more frequently in CK 7-negative livers than in positive livers. Proliferation of CK 7- and CK 19-positive bile ductules and bile ductular-like (oval) cells was frequently associated with the DEN-induced liver injury and hepatocarcinogenesis. CONCLUSIONS: This is the first report on CK expression in monkey liver. The findings show that the hepatocyte specific pattern is not always preserved during DEN-induced hepatocarcinogenesis and may therefore not be useful in differentiating between HCCs and cholangiocarcinomas.

Animals↗
PubMed1994

Clinical and radiographic healing pattern observations with combined regenerative techniques.

Clinical and radiographic healing observations were categorized into four patterns: rapid, typical, delayed, and adverse. While considerable overlap of characteristics was noted between the categories, singular factors or combinations of factors enabled pattern identification. The factor primarily associated with the rapid healing pattern was the appearance of bone in the former defect adjacent to the membrane at removal. In contrast, the adverse healing pattern depicted surface necrosis or loss of tissue height at membrane removal. One hundred random sites were evaluated, revealing 13% rapid healing patterns, 76% typical healing patterns, 8% delayed healing patterns, and 3% adverse healing patterns. With favorable patient compliance with oral hygiene and follow-up care, the rapid and typical healing patterns became clinically successful cases. The level of clinical success varied with the delayed healing pattern; the adverse pattern failed to achieve the therapeutic objective.

Alveolar Bone Loss↗
PubMed1994

[An evaluation of the pulmonary venous flow pattern by transesophageal and transthoracic Doppler echocardiography in a normal subject].

Transesophageal echocardiographic studies have permitted a pulmonary venous flow velocity pattern to be identified which is comparable to that recorder using invasive methods. The pattern consists of 4 stages: an anterograde systolic flow with an early (S1) and late (S2) peak velocity, a diastolic anterograde flow (D) and a retrograde flow liked to atrial contraction (Ar). The aim of this study was to evaluate the pattern of pulmonary venous flow velocity using transesophageal and transthoracic colour Doppler echocardiography in normal subjects in an attempt to: 1) determine normal values derived from the pulmonary venous flow pattern which may contribute to future studies; 2) find correlations between the pattern of pulmonary venous flow and a number of physiological, hemodynamic and echocardiographic parameters which take account of the morphological variations of this flow pattern within a normal range; 3) demonstrate the possibility of being able to carry out study using transthoracic colour Doppler echocardiography. The study was carried out in 38 normal subjects aged between 15 and 76 years old (mean 45 +/- 15) who underwent transthoracic and transesophageal colour-Doppler echocardiography. The following parameters were measured: left atrium diameter, diameters and telediastolic and telesystolic volumes of the left ventricle, ejection fraction and systolic percentage shortening of the left ventricle, peak velocity of the mitral flow pattern and the pulmonary venous flow pattern. The results obtained show that: 1) the pattern of pulmonary venous flow alters with ageing causing the prevalence of systolic over diastolic peak velocity; 2) the pulmonary venous flow parameters which appear to be most significant in hemodynamic terms are the peak velocities of the early systolic flow and anterograde diastolic flow and the ratios S1/S2 and S2/D; 3) the echocardiographic parameters most closely correlated with the peak velocity of pulmonary venous flow are the dimensions of the left atrium, telediastolic and telesystolic ventricular volumes, and the pattern of transmitral flow; 4) heart rate does not appear to influence the pulmonary venous flow pattern significantly (at least within the range of 50-100 b/min), except for retrograde flow. Similar results were obtained using transesophageal and transthoracic Doppler echocardiography and therefore if future studies succeed in obtaining useful information, of not only speculative but also practical interest, from the evaluation of pulmonary venous flow, these can be obtained using a simple, widespread and completely non-invasive method such as transthoracic Doppler echocardiography.

Adolescent↗
PubMed1994

Fetal NGF augmentation preserves excess trigeminal ganglion cells and interrupts whisker-related pattern formation.

In the developing nervous system, precisely patterned connections result from mechanisms that remodel initially diffuse connections. For example, ocular dominance column formation depends upon activity-based competitive interactions. In the developing trigeminal (V) somatosensory system, injury to afferent inputs prevents somatotopic pattern formation; however, afferent impulse blockade does not. What establishes central V patterns remains unclear. As a first step in assessing the role of neurotrophins in naturally occurring death of V ganglion cells and whisker-related pattern formation, the consequences of prenatal NGF injections were evaluated. Fetal rats given NGF on both embryonic day (E) 15 and E18 had 36% more V ganglion cells than normal and lacked whisker-related patterns in the V brainstem complex at birth and through postnatal day 3, as determined by cytochrome oxidase histochemistry. Rats injected with NGF on E16 or on E18, or with vehicle had normal ganglion cell numbers and brainstem patterns. Animals injected with antibodies to NGF or an NGF receptor had reduced ganglion cell numbers and normal brainstem patterns. These findings suggest that naturally occurring cell death in the V ganglion is neurotrophically regulated and that this process impacts upon somatotopic pattern formation in the V brainstem complex. Results of anterograde tracing experiments in NGF-augmented animals suggest that pattern disruptions are due to an absence of whisker-related patterning in the central projections of V ganglion cells. Moreover, single primary afferent collaterals labeled by Neurobiotin injections in the V ganglion did not have widespread or unusually complex arbors. Thus, NGF may affect V pattern formation by preserving or inducing projections to brainstem regions that normally come to lack such projections, such as the spaces normally demarcating neighboring whisker primary afferent projections.

Animals↗