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PubMed1989

Patterns and correlates of psychiatric hospitalization in a nationwide sample. I. Patterns of hospitalization with special reference to the "new chronic" patients.

A nationwide random sample of psychiatric patients (n = 832) admitted for hospitalization in Israel in 1980 was followed up until the end of 1984 regarding their hospitalization patterns. Information about hospitalizations as well as demographic and diagnostic data were obtained from the Israel Central Psychiatric Case Register. Two main contrasting patterns of hospitalization emerged. One pattern consisted of a single short hospitalization during the entire follow-up period. This pattern was found among more than 50% of those patients for whom this hospitalization was the first in their life. The second pattern characterized the patients who accumulated long periods of inpatient stay, that is, at least one year during the follow-up period. These are the "new chronic" patients (about 30% of the total sample). About one third of these "new chronic" patients (8.2% of the total sample) accumulated their long stay through one continuous hospitalization, thus resembling the "old chronic" patients; two-thirds accumulated their long stay over several hospitalizations. Each patient has a fairly constant pattern of hospitalization, regarding the length of stay in hospital and out of hospital.

Chronic Disease↗
PubMed1990

Pattern regulation in the ventral histoblasts of the housefly: induction of sternal pattern abnormalities by mechanical wounding of larval epidermal cells.

In higher Diptera, two nests of diploid cells called the ventral histoblasts, located one on either side of each abdominal segment among the polytene larval epidermal cells, give rise to the sternite and its surrounding pleura. During metamorphosis of the insect, these two groups of cells migrate and meet with each other in the midventral region of the developing adult. The cuticular pattern elements and pigmentation in the fifth sternite of the male housefly, when compared to those of other segments as well as the tergites of both sexes, are quite distinct. The above-mentioned features, coupled with the smaller number and predictable occurrence of one of the pattern elements in this sternite, viz, the primary forceps, help one to determine the developmental potential of the histoblast nest and the regulation of its potential which occur at the time of fusion of the two contralateral nests of this segment. A simple operation of slitting the larval epidermal cells (LEC) in a hemisegment in the vicinity of the histoblast nest or extirpation or rotation of a small rectangular piece of LEC between the ventral nest and the midventral line produced pattern abnormalities including mirror image duplication in the hemisternite. An analysis of these pattern abnormalities in the different segments and, in particular, in the fifth segment provides a dynamic picture of the formation of the median sternite. Further, these abnormalities indicate the significance of the presence of the intervening pleural cells between the confronting hemisternites under experimental conditions. Thus, each of the fifth ventral nests has the developmental potential to form more than half of the final sternite pattern. Possible mechanisms for the formation of the normal median sternite during metamorphosis and for the formation of duplicated hemisternites and their fusion products under experimental conditions are discussed in light of current models of pattern regulation.

Animals↗
PubMed1986

EEG characteristics of epileptic pattern sensitivity and their relation to the nature of pattern stimulation and the effects of sodium valproate.

Seven patients with pattern-sensitive epilepsy were examined repeatedly over a period of 4-12 months during which the dose of sodium valproate was adjusted. Patterns were presented in series in which the size of successive patterns was progressively increased until paroxysmal activity appeared, or until the largest pattern (radius 24 degrees visual angle) had been presented. As valproate dose increased, paroxysmal activity was less likely to occur. When it did occur it was less likely to include a spike; it had a lower voltage, involved fewer electrodes, and lasted a shorter time. The size of the pattern just sufficient to induce paroxysmal activity showed relatively little change with valproate dose. The degree to which the various electrodes were involved in the discharges showed considerable stability. The paroxysmal response to patterns presented in one visual half-field was almost invariably maximal over the contralateral posterior quadrant, usually at the posterior temporal electrode.

Adolescent↗
PubMed1990

Size-dependent pigmentation-pattern formation in embryos of Alligator mississippiensis: time of initiation of pattern generation mechanism.

The pigmentation pattern of Alligator mississippiensis was examined. The number of white stripes on the dorsal side of embryos (stages 21-28) and hatchlings from eggs incubated at 30 degrees C (100% females) and 33 degrees C (100% males) was recorded. Total length, nape-rump length and tail length were recorded for each embryo and hatchling. The number of white stripes was affected by incubation temperature but not sex; hatchlings incubated at 33 degrees C had two more white stripes than those at 30 degrees C, despite being the same length. Five female hatchlings produced at 33 degrees C by manipulation of the temperature, had the same number of stripes as males that developed under the same incubation temperatures. The appearance of the pigmentation was accelerated in embryos incubated at 33 degrees C, occurring eight days earlier than at 30 degrees C. At the time just before the first signs of pigment deposition, embryos from 33 degrees C were longer than those at 30 degrees C. If the stripe formation is size dependent this explains why hatchlings at 33 degrees C have more stripes than hatchlings from 30 degrees C. The mechanism that produces the stripe patterns is unknown. We describe key elements a pattern formation mechanism must possess to produce such stripes and suggest a possible mechanism, based on cell movement driven by chemotaxis. We apply the mathematical model to dorsal patterning on A. mississippiensis. We show how length at pattern formation is the prime factor in determining stripe number and how the pattern can be formed in the observed anterior-posterior sequence. We present numerical simulations and show that the qualitative behaviour is consistent with the experimental results.

Alligators and Crocodiles↗
PubMed1988

Ultrasonographically defined parenchymal patterns of the breast: relationship to mammographic patterns and other risk factors for breast cancer.

We have used ultrasound of the breast to define four parenchymal patterns in which increasing proportions of the breast are replaced by densely echogenic tissue. A series of 452 symptomatic women examined by both ultrasound and conventional X-ray mammography was reviewed to determine whether these ultrasonographic images could predict the breast parenchymal pattern defined mammographically. A very strong correlation was demonstrated between the breast pattern on ultrasound and the volume of the breast replaced by either dysplasia (Kendall's tau-b = 0.731 +/- 0.026, p less than 0.0001) or ductal prominence (Kendall's tau-b = 0.641 +/- 0.049, p less than 0.0001). This was seen both on initial reporting and on a blind re-reading of a random sample of 100 cases. The strength of correlation was similar for subgroups defined by family history of breast cancer, age, menopausal status, and history of benign breast disease, and the breast parenchymal pattern assessed by mammography or ultrasound showed similar associations with these variables. Ultrasonographic parenchymal patterns of the breast can predict the tissue patterns defined mammographically and may therefore be useful as a marker of breast cancer risk.

Adult↗
PubMed1990

[DNA ploidy pattern of gastric carcinomas and its relations with histological type and invasion pattern].

The DNA ploidy pattern was determined by cytofluorometry in 90 cases of surgically resected gastric carcinomas, which were histologically divided into 40 cases of differentiated type and 50 of undifferentiated type. The gastric cancers were classified into two basic ploidy patterns, diploid and aneuploid. Relations among ploidy patterns, histological types and invasion patterns were studied. Diploid patterns were found in 23 cases (58%) of differentiated type and in 37 (74%) of undifferentiated type. In undifferentiated types, aneuploid patterns appeared in 2 (10%) of 19 early cancers, whose rate was significantly lower than that of advanced cancers. 11 (38%) of 29. In differentiated types, however, aneuploids were seen in 10 (48%) of 21 early cancers, not lower than 7 (37%) of 19 advanced ones. Furthermore, in undifferentiated types, aneuploids marked 11 (52%) out of 21 highly invasive carcinomas, while no aneuploids appeared in slightly invasive ones. In differentiated types, aneuploids were found in 3 (38%) out of 8 intramucosal carcinomas and 9 (53%) out of 17 slightly invasive ones. These results suggested that in undifferentiated gastric carcinomas, aneuploid is closely correlated with tumor progression and invasion degree, whereas in differentiated carcinomas such a correlation is not clearly seen.

DNA, Neoplasm↗
PubMed1985

Dynamics of the control of body pattern in the development of Xenopus laevis. III. Timing and pattern after u.v. irradiation of the egg and after excision of presumptive head endo-mesoderm.

A series of Xenopus egg batches has been exposed to doses of u.v. (2537A) light on the vegetal hemisphere at precleavage stages, calculated to result in a range of minimal axial deficiency syndromes in the developing larvae. At the time of onset of gastrulation in synchronously fertilized but non-irradiated batch members, each experimental group was regularly scanned so that small subsamples of embryos could be set aside as showing particular, progressive degrees of delay in onset of the visible gastrulation movements. Such sampling was found to have preselected embryos showing generally progressive degrees of pattern impairment at larval stages, and this observation was extended by histological examination of the anterior axial anatomy. Such examination was also made of the least abnormal-looking members of a series of larvae resulting from excision of the presumptive head endo-mesoderm, traditionally called 'the organizer', from stage-10 gastrulae (Cooke, 1975). The results support the notion that production of the most anterior endo-mesodermal pattern parts (and of their inductive capacities in giving rise to the brain pattern) occurs only in material whose timing, in the onset of gastrulation activity, is close to the normal onset time after fertilization. Either an early failure of the egg to generate a location with the 'position value' corresponding with this extreme of the pattern, or the much later excision of the region from a physiologically normal gastrula, results in a system of pattern formation permanently truncated at its apical (head and dorsal) end. There is no evidence for any dynamic, in the system ascribing position value, that will cause regulative restoration of this cellular state (the most extreme 'activation' for development) in response to its absence after precleavage stages. An earlier statement (Cooke, 1975) that this could occur was based upon inadequate analysis of larvae with an often misleading external anatomy. The present results are discussed as supporting the overall view of the early Xenopus patterning system that has been developed in the previous two papers of the series.

Animals↗
PubMed1985

Dynamics of the control of body pattern in the development of Xenopus laevis. I. Timing and pattern in the development of dorsoanterior and posterior blastomere pairs, isolated at the 4-cell stage.

Xenopus embryos have been selected in which the second cleavage is occurring in a frontal plane, i.e. one tending to lie at right angles to the prospective plane of bilateral symmetry for the body pattern. Some of these have been used to deduce a map of the disposition of materials for the normal mesodermal pattern (the normal 'fate map') by injecting blastomeres to found fluorescently marked clones from 4- to 32-cell stages. Other such 4-cell embryos have been separated into two isolates across this second cleavage; in fate-map terms, prospective dorsoanterior and posterior isolates. These have been allowed to develop to control axial larval stages, with examination of the time schedule of their gastrulation movements in relation to cofertilized whole controls. The patterns of mesoderm produced have been examined and interpreted in the light of quantitative knowledge about the normal pattern, and our current understanding of the map. A meaningful fate map exists for the egg material even at this early, essentially acellular stage, and it differs appreciably from what might have been expected in view of that traditionally shown for early gastrula stages. The patterns developed in the isolates show that at least in many eggs, widespread information that positively specifies material as to its body position is available from at most 1 h after the events that give rise to bilateral symmetry upon fertilization. This information usually leads to a mosaic development of the appropriate mesodermal part-pattern in dorsoanterior isolates, and frequently allows development that approximates to this in the reciprocal posterior part. Regulation, i.e. the replacement of removed information to specify a development more complete than the normal contribution in isolates, is not observed. The results suggest a revision of former claims for regulative ability in at least this amphibian embryo. They also imply that systems for ascribing position value (positional information) to early embryonic tissue can be diverse in dynamics, even among embryos whose body plans are obviously homologous as are those of vertebrates.

Animals↗
PubMed1992

The pattern visual evoked potential and pattern electroretinogram in drusen-associated optic neuropathy.

Sixteen patients (29 eyes) with optic disc drusen were studied prospectively for clinical and electrophysiologic evidence of impaired optic nerve conduction. Abnormalities were detected in the following areas: visual acuity, eight (28%) of 29 eyes; kinetic visual field, 22 (76%) of 29 eyes; results of Farnsworth-Munsell 100-Hue test, 12 (41%) of 29 eyes; and flash visual evoked potential, 13 (54%) of 24 eyes. Simultaneous pattern visual evoked potentials and results of pattern electroretinograms were recorded. The P100 latency of the pattern visual evoked potential was prolonged in 41% of eyes. The P50 and N95 components of the pattern electroretinogram were also analyzed. The P50 amplitude was reduced in only four (17%) of 24 eyes. The most common abnormality was a reduction in amplitude or the absence of the N95 component in 19 (79%) of 24 eyes, reflecting ganglion cell dysfunction. The data support mounting evidence that the P50 and N95 components of the pattern electroretinogram have different retinal origins.

Adolescent↗
PubMed1992

The pattern ERG in glaucoma: effect of pattern reversal time.

Pattern reversals with a ramp-like temporal course evoke transient pattern electroretinograms (PERG) that are delayed and attenuated in comparison with responses evoked by a step-like course (abrupt pattern reversals). This delay depends on the reversal time and probably represents a measure for temporal characteristics of the activated retinal structures. A pattern reversal stimulator with adjustable reversal periods (matrix of 8 x 14 rectangular red light emitting diodes, element size 2 degrees x 1 degree, stimulus area 16 degrees x 14 degrees) was used to record transient PERGs from 20 glaucomatous eyes with early or moderate visual field damages (measured with computer perimetry). The q-wave (P1) amplitude difference between the glaucoma group and normal subjects with step-like reversal stimulation was not significant (P = 0.23). On the other hand, a highly significant separation (P < 0.0001) between both groups was possible using the P1 latency at ramp-like stimulation or the response latency shift between step and ramp-like stimulation (Pattern reversal time, 30 ms).

Chronic Disease↗
PubMed1987

Aftereffect of induced rotation: number of pattern elements and area of pattern in inducing stimulus.

Previous research has suggested that aftereffect of induced rotation can be longer when the number of pattern elements in the inducing stimulus is greater. This was explained by the amount of shearing between pattern elements of inducing and static stimuli. However, the results might also be explained by the greater area occupied by a greater number of pattern elements. The present experiment used three inducing stimuli, in which number of pattern elements and area of pattern were varied independently, to test between these hypotheses. The former was corroborated and the latter refuted.

Adult↗
PubMed1975

Cytophysiological basis of disruptive pigmentary patterns in the leopard frog Rana pipiens. II. Wild type and mutant cell-specific patterns.

A new pattern index, Ip, is introduced and used to compare patterns of wild type, burnsi, and kandiyohi chromatophores in the leopard frog, Rana pipiens. Wild type chromatophores are hyperdispersed over distances within cellular contact, and it is concluded that this hyperdispersion results from contact-mediated negative interactions. The hyperdispersion is less strong in spot cells than interspot, and extends over larger areas in burnsi than in wild type epidermis. Over areas greater than chromatophore size, patterns are either random or clumped. Patterning of kandiyohi melanophores is clumped into aggregates small enough to be within the range of cellular contact, suggesting a lack of contact inhibition among these cells. The possible roles of cellular properties and the extracellular environment in pattern determination are discussed.

Animals↗
PubMed1975

Chromosome banding pattern conservatism in birds and nonhomology of chromosome banding patterns between birds, turtles, snakes and amphibians.

The G-banded karyotypes of 4 species of birds representing the orders Galliformes, Columbiformes and Musophagiformes were compared. Banding pattern homology between orders was limited t 5o 5 major chromosome arms and the Z chromosome. Even in these major chromosome arms pericentric and paracentric inversions produced alteration of the banding pattern sequences. Addition of constitutive heterochromatin was responsible for changes in banding patterns in the Z chromosome. The chromosome banding patterns of an emydid turtle, Terrepene carolina, 5 species of boid snakes of the genera Liasis, Acrantophis, and Sanzinia and the African clawed-frog. Xenopus muelleri, were also compared to the bird chromosome banding patterns. No homology was observed between any of these major groups: bird, snake, turtle, amphibian. However, intergroup homology was apparent. - The data obtained do not support reports of broad interordinal direct homology of the macrochromosomes of birds and refutes the idea of a primitive bird karyotype with 3 pairs of "Agroup' chromosomes and 3 pairs of "B group' chromosomes. - The major mechanisms responsible for chromosome evolution in birds appear to be centric and tandem fusions, paracentric and pericentric inversions, and addition or deletion of heterochromatin.

Animals↗