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PubMed1991

Predictive testing for Wilson's disease using tightly linked and flanking DNA markers.

We studied DNA polymorphisms for five new chromosome 13 markers in 52 Wilson's disease (WD) families from Europe, North America, and the Middle East. There was significant evidence for linkage between the Wilson's disease locus (WND) and all the marker loci. Multilocus linkage analysis, using a genetic linkage map established from reference pedigrees, suggested that WND is most likely between D13S31 and D13S59, at distances of 0.4 and 1.2 centimorgans, respectively. Our results suggest that the chromosomal location of the Wilson's disease gene is the same in all families from the populations studied. This evidence and the availability of many close, flanking, and polymorphic DNA markers make possible accurate and informative testing of potential carriers and WD homozygotes in families with at least one previously affected child. An advantage of a genetic linkage test over other laboratory methods for prediction of genotype in WD is that a reliable diagnosis can be made at a much earlier stage in life, including prenatally. In addition, DNA testing can be used in place of an invasive liver biopsy procedure to confirm a diagnosis in patients with borderline serum ceruloplasmin levels. Presymptomatic identification will also allow therapeutic intervention to prevent symptoms before irreparable liver or neurologic damage occurs. We describe the implementation of prenatal and preclinical diagnosis for two families with WD.

Chromosome Mapping↗

PubMed1990

Afferent and efferent connections of the oculomotor region of the fastigial nucleus in the macaque monkey.

Afferent and efferent connections of the fastigial oculomotor region (FOR) were studied in macaque monkeys by using axonal transport of wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP). When injected HRP is confined to the FOR, retrogradely labeled cells appear in lobules VIc and VII of the ipsilateral vermis and in group b of the contralateral medial accessory olive (MAO). In reference to the maps of topographical organization, the extent of the effective site in the fastigial nucleus (FN) could be assessed from the distributions of labeled Purkinje cells (P cells) in the vermis and labeled olivary neurons in the MAO. In contrast to the unilateral nature of the P-cell and climbing-fiber projections, those from the other brainstem regions to the FOR were bilateral. Following the injection of HRP into the FOR, the largest number of retrogradely labeled cells appeared in the pontine nuclei. Although the number of labeled cells was greater on the contralateral side in both the peduncular and dorsomedial pontine nuclei (DMPN), the number of each side was virtually identical in the dorsolateral pontine nucleus (DLPN). In the nucleus reticularis tegmenti pontis (NRTP), labeled cells were located only in its medial and dorsolateral portions bilaterally. In the vestibular complex, labeled cells appeared in the superior (SVN), medial (MVN), and inferior vestibular nuclei (IVN) bilaterally. The lateral vestibular nucleus (LVN), including y group and the ventrolateral vestibular nucleus, were free of labeled cells. Labeled cells appeared also in the perihypoglossal nucleus (PHN) bilaterally. In the pontine raphe (PR) and paramedian pontine reticular formation (PPRF), labeled cells appeared bilaterally in the caudal third of the area between the oculomotor and abducens nuclei. Labeled cells appeared also in the mesencephalic and medullary reticular formation. Tracing of anterogradely labeled axons demonstrated that most fibers from the FOR decussated within the cerebellum and entered the brainstem via the contralateral uncinate fasciculus. Some crossed fibers ascended with the contralateral brachium conjunctivum and terminated in the midbrain tegmentum. A small contingent of fibers advanced further to the thalamus. In the mesodiencephalic junction, labeled terminals were found contralaterally in the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF) and a medial portion of FOrel's H Field. They appeared also in the central mesencephalic reticular formation (cMRF), the periaqueductal gray (PAG), the posterior commissure nucleus, and the superior colliculus. The oculomotor and trochlear nuclei, the red nucleus, and the interstitial nucleus of Cajal were free of labeled terminals.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗

PubMed1990

The decomposition of the middle latency auditory evoked potential (MLAEP) Pa component into superficial and deep source contributions.

The results of recent investigations have suggested that the Middle Latency Auditory Evoked Potential (MLAEP) Pa component derives its physiological origins from both cortical and subcortical sources. The purpose of the present investigation was to determine if support for this hypothesis could be obtained from the off-line manipulation of the topographically recorded Pa component. The multichannel MLAEP from 15 normal hearing, neurologically intact subjects was collected following monaural left and right ear click stimulation. Data was originally collected using the linked ear reference and was subsequently re-referenced using the common average reference (CAR). These mapped data were converted off-line to source current density using the source derivation (SD) technique described by Hjorth (1975, 1980). This technique is sensitive to current activity that is generated in the superficial cerebral cortex. These SD maps of the MLAEP were subsequently subtracted from the CAR maps of the MLAEP. The derived CAR-SD maps are believed to represent that activity that is generated deep to the cerebral cortex (Hjorth and Rodin 1988). Interpretation of the mapped data have demonstrated support for the hypothesis that Pa is generated by a minimum of two systems including: 1) bilateral sources located in the posterior temporal lobes, and 2) a deeper midline generator system.

Acoustic Stimulation↗

PubMed1985

Variation among hepatitis A virus strains. I. Genomic variation detected by T1 oligonucleotide mapping.

The genomes of eight hepatitis A virus (HAV) strains originating from far distant geographic regions such as Europe, North Africa, Middle and North America, Australia and The People's Republic of China were compared by RNase T1 oligonucleotide mapping. For this purpose, the viruses were propagated in cell cultures and viral RNA was isolated from highly purified mature virions. It could be shown that variation in nucleotide sequence is common among HAV isolates, but is in the order of magnitude reported for other picornaviruses. For viruses isolated in cell culture directly from stool samples of diseased individuals, changes usually amounted to 1-4% of RNA genome sites. Genomic differences between two virus strains derived from one fecal sample but replicating at either 32 or 37 degrees C were in the same order of magnitude. Thereby, the number of consecutive in vitro passages proved to have only limited influence on the development of genetic variation. For two HAV strains, however, adaptation to and passage in marmosets evidently had imposed highly selective conditions which had favored the appearance of viral genomes differing in up to 75% of their large oligonucleotides (about 10% in sequence) from the oligonucleotide map of a reference HAV strain.

Animals↗

PubMed2026

A genome-wide coverage-based pipeline for the identification of host-derived candidate DNA biomarkers from cell-free blood.

We have created a new data-analysis pipeline for the discovery of host-specific candidate DNA biomarkers derived from sequencing data of cell-free blood. Unlike approaches that rely on specific molecular or genetic signatures, our method leverages the coverage distribution of cell-free DNA sequences mapped to a reference genome, applying statistical analyses to identify informative short genomic regions for biomarker discovery. The pipeline is applicable to diverse diseases and can be used to analyze cell-free DNA sequences from plasma or serum to identify candidate biomarkers that are characteristic of disease states in mammals. Core functionalities were developed in Java and integrated with open-source software tools for the preprocessing of raw sequencing data, complemented by Python scripts for the machine-learning analysis and statistical validation. The pipeline is designed for HPC use and users can access the pipeline through a Galaxy workflow, which offers a user-friendly web interface for input selection prior to execution and analysis progress monitoring. Performance tests, carried out using duplicate sets of COVID-19 samples and controls, showed linear scalability of execution time with an increasing dataset size, as well as a substantial reduction in execution time through parallelized computation, whereby each HPC node is used to process the data of one chromosome. Further statistical tests confirmed the quality of the pipeline's results by showing that the set of identified candidate biomarkers remained stable across varying dataset sizes.

Biomarkers↗

PubMed1997

Human genetic diseases: a cross-talk between man and yeast.

A sequence similarity search has been carried out against the complete Saccharomyces cerevisiae genome to identify the yeast homologues of human disease-associated genes. Using the BLAST algorithm (Basic Local Alignment Search Tool), it was found that 52 out of the 170 disease genes identified without reference to chromosomal map position and 22 of the 80 (27.5%) positionally cloned genes match yeast genes with a P-value of <e(-40). The percentage of the disease genes identified by positional cloning which bear homology to yeast is similar to that of a random collection of human cDNAs. The biochemical and physiological functions of the large majority of these human genes remain poorly understood and, even though a strict conservation of function cannot safely be assessed from structural homology analysis without the support of experimental and three-dimensional data, functional analogies can often be established between the human and yeast genes.

Chromosome Mapping↗

PubMed1998

The effect of gaze eccentricity on perceived sound direction and its relation to visual localization.

This study investigates the influence of eye position on the localization of a free-field sound source by employing a pointing method. While fixating visual targets in various directions, the subjects indicated the perceived direction of a sound source by adjusting the azimuthal angle of a swivel pointer. The perceived sound azimuth shifted consistently opposite to the direction of eccentric gaze. i.e. to the left when gaze was to the right and vice versa. This shift resembled an approximately linear function of horizontal gaze direction. The mean magnitude of the shift was 3.1 degrees when the gaze was 45 degrees to the side (mean slope 0.069 degrees per degree eccentricity in gaze direction). An additional experiment investigated the relation of this effect to visual localization. Using the same method, the shift of perceived visual azimuth was measured as a function of gaze direction. The results indicate a shift in the same direction as the auditory shift (opposite to the direction of eccentric gaze), but with a significantly greater magnitude, which was 5.7 degrees for 45 degrees eccentricity in gaze direction. The perceived shifts of sound direction depending on gaze eccentricity may result from incomplete transformations of the auditory spatial coordinates from a craniocentric to an oculocentric frame of reference within neural maps of space, as has been suggested by previous neurophysiological investigations.

Acoustic Stimulation↗

PubMed1986

Correspondence analysis applied to steroid receptor binding.

The relative binding affinities of 48 steroids for four classes of hormone receptor (progestin, PR; androgen, AR; glucocorticoid, GR; mineralocorticoid, MR) have been analyzed by correspondence analysis. The steroids were, for the most part, derivatives of nortestosterone, differing by their degree of unsaturation, by the presence or absence of a 17 alpha-ethynyl group, and by the length of the C-13 alkyl substituent. Derivatives of norprogesterone were included as reference compounds. Distribution maps visualizing the results of the mathematical analysis revealed that the majority of the test steroids were within the zone of influence of AR and PR and had limited affinity for GR and MR. Overall lack of specificity and enhanced affinity for GR and MR were induced by increasing unsaturation and by the presence of a C-13 ethyl group. The general and specific conclusions of the analysis confirm and extend previous intuitive and partial interpretations of the data. Correspondence analysis, however, has the advantage of taking into account the sum total of the available information, without any preconceived notion of the relative importance of a specific structural feature or biological parameter and, furthermore, enables simultaneous representation on a single graph of the receptor and steroid fields. The present example demonstrates the use of this type of methodology in processing routine screening data involving multiple parameters.

Chemical Phenomena↗

PubMed1994

Acquisition of procedural skills from examples.

Three experiments were run in which Ss first memorized examples of input-output pairs and then generated the outputs for a series of new inputs by analogy to the original examples. Ss first performed these mappings by explicit analogy to an example, but with practice they learned to make these input-output mappings directly without reference to the examples. Ss sped up as a power function of practice over a day (Experiment 1) or days (Experiments 2 and 3). Ss developed a directional asymmetry such that they were slower to calculate the input from the output than the output from the input (whereas initially they had not been). Ss showed similar speed up in their ability to recall the original examples but did not show the same directional asymmetry. Initially, there was some transfer from practicing the procedure to recalling the examples, but this diminished over days.

Cognition↗

PubMed1985

Chromosomal location of the gene encoding the neural cell adhesion molecule (N-CAM) in the mouse.

The gene encoding the neural cell adhesion molecule, N-CAM, has been localized on mouse chromosome 9. A BALB/cJ mouse genomic library prepared in lambda bacteriophage EMBL4 was screened by using a cDNA probe, pEC204, that corresponds to the coding region of the chicken N-CAM gene. Four weakly reactive and one strongly reactive recombinant phage were isolated. A region of the latter that was strongly homologous to pEC204 was subcloned to yield a new probe, pEC501. RNA transfer blots and nucleotide sequencing indicated that pEC501 encoded part of the mouse N-CAM gene. This probe defined a unique genetic locus, Ncam, associated with a restriction fragment length polymorphism that allowed the definition of two alleles. The locus could be provisionally assigned either to chromosome 9 or to chromosome 10 by correlating the presence or absence of mouse-specific DNA fragments reactive with the probe in a panel of somatic hybrid cell lines with the presence or absence of the various mouse chromosomes. Analysis of the inheritance of the Ncam-associated DNA polymorphism in recombinant inbred strains of mice revealed close linkage between Ncam and the Lap-1, Sep-1, and Thy-1 loci on chromosome 9. This result suggests an additional linkage between Ncam and the locus for the cerebellar mutation staggerer (sg). The Ncam locus provides an important reference point for mapping the genes for additional cell adhesion molecules as well as genes for other molecules involved in neural development and function.

Animals↗

PubMed1986

Words created by children versus aphasic adults: an analysis of their form and communicative effectiveness.

The creation of words through the novel combination of English morphemes (e.g., "map ball" to refer to a globe) was studied in 40 preschool children, 40 grade school children, and 40 adults. These lexical innovations were collected while subjects named pictured objects, and were evaluated in terms of incidence, communicative effectiveness, novelty, semantic accuracy, and certain linguistic characteristics. Preschool children's innovations were as communicatively effective as those of grade school children and adults and contained the highest proportion of innovations with redundant elements. Grade school children produced the highest proportion with semantic inaccuracies. This suggests that preschoolers invent words from a limited set of highly familiar terms, whereas grade schoolers rely more on partially known terms. In addition, the children's innovations differed significantly from those previously collected from aphasic adults. This demonstrates that aphasia does not cause a regression to an early level of linguistic sophistication.

Anomia↗

PubMed1984

The nucleotide recognized by the Escherichia coli A restriction and modification enzyme.

The nucleotide recognition sequence for the restriction-modification enzyme of Escherichia coli A (EcoA) has been determined to be GAG-7N-GTCA. This sequence is fairly similar, but distinctly different from the two other type I restriction enzyme recognition sites known for E. coli B and E. coli K12, respectively. N6-adenosine methylation has been observed at nucleotide positions 2 and 12 within that sequence after modification by EcoA. As a reference point for mapping the single EcoA site in lambda, the position of lambda point mutation Oam29 has been determined also.

Base Sequence↗

PubMed1991

Enzymatic cleavage of a bacterial chromosome at a transposon-inserted rare site.

The sequential use of the methylase M.Xbal (5'.TCTAGm6A) and the methylation-dependent endonuclease Dpnl (5'-Gm6A decreases TC) results in cleavage at 5'.TCTAGA decreases TCTAGA. This recognition sequence was introduced into a transposon derived from the Mu bacteriophage and transposed into the genome of the bacterium Salmonella typhimurium. M.Xbal methylation was provided in vivo by a plasmid containing the M.Xbal gene and the S. typhimurium genome was cleaved to completion by Dpnl at one or more sites, depending on the number of transposon insertions. The resulting genomic fragments were resolved by pulsed-field electrophoresis. The potential use of single M.Xbal/Dpnl cleavage sites as reference positions to map rare restriction sites is discussed.

Base Sequence↗

PubMed1993

Branch duct origin of solid type pancreatic ductal carcinoma.

A case of branch duct origin of solid type pancreatic ductal carcinoma is presented. Stepwise tissue sections of an entire specimen, including the carcinoma area, and mapping, with special reference to the relationship between the main duct and the carcinoma area, were performed. Carcinoma cells of the branch duct showed intraductal spread with minimal stromal invasion. No carcinoma tissue was observed in the main duct. Therefore this case was considered to be of branch duct origin. The finding of histologically identified branch duct origin of solid type pancreatic ductal carcinoma indicates a distinct advantage to be gained by giving special attention to both the main and branch ducts when using image diagnosis for early detection of carcinomas, and may represent the first reported surgically resected case.

Humans↗

PubMed1994

Therapy with refugee families: what is a "good" conversation?

This article addresses the question of what is a "good" conversation by analyzing "poor" conversations. During a project on family therapy with refugee families, we often experienced what we labeled as "poor" conversations. We present examples of a variety of such conversations, which we then analyze with reference to therapeutic maps and central concerns of the therapists. We describe four patterns of therapist/client relationships that emerged from this analysis. The main focus of our discussion is to clarify when "poor" conversations may be an important part of the therapeutic process, and when and how they should be avoided. We believe that the issues we raise are central to therapeutic work in general and not just to therapy with refugee families.

Acculturation↗

PubMed1978

The vestibular nuclei in the domestic hen (Gallus domesticus). IV. The projection to the spinal cord.

Horseradish peroxidase was injected at various levels of the spinal cord of the hen and the cells in the brain stem, labeled due to retrograde transport of the tracer enzyme, were mapped with particular reference to the vestibular nuclear complex. The Deiters' nuclei project ipsilaterally to the spinal cord. The projection from the nucleus Deiters ventralis reaches down to the lumbosacral spinal cord. The spinal projection from the nucleus Deiters dorsalis is somatotopically organized. Cells localized rostrally within the nucleus project to upper parts of the spinal cord cells localized caudally project to the lumbosacral spinal cord. The medial and the descending nucleus contain labeled cells in two compartments of the nuclei. In each of them a rostral one projects to the upper cervical cord, a caudal one projects to the thoracical spinal cord. In addition, labeled cells are observed in the reticular formation, mainly in the pons and the medulla oblongata, in the red nucleus, in the raphe nuclei and in the periaqueductal grey. Very few labeled cells are observed in the locus ceruleus, the nucleus intercalatus and in the nucleus of the solitary tract. In some cases, the number of labeled cells in the various nuclei in the brain stem projecting to the spinal cord was counted to get an impression of the quantitative importance of the vestibulospinal projection relative to afferents to the spinal cord from the other nuclei. The findings are discussed in the light of what is known of the vestibulospinal projection in mammals.

Animals↗

PubMedDate not supplied

Non-invasive external regional measurement of cerebral circulation time changes in supratentorial infarctions using pertechnetate.

A method for measuring regional cerebral circulation time (rCCT) between the hemispheres using intravenous pertechnetate and a multidetector system is presented. Interhemispheric differences of rCCT instead of absolute values were selected because of the variation of pertechnetate bolus dispersion due to changes in the systemic circulation and injection technique inter-and intraindividually. Time activity curves over one minute were analyzed by a modified gamma function fitting method. The results are printed as a brain map which shows reference values and abnormal findings. Abnormal rCCT asymmetry was observed in 10 out of 77 controls (13%) and 58 out of 65 patients with cerebral infarction (89%). Within 2 weeks after a stroke shorter circulation time values on the side of the lesion than on the contralateral side were found in 5 patients. In the severe infarction cases and in the acute stages of infarction circulatory changes could be found in a great number of areas. In patients with manifest diabetes abnormal circulatory findings occurred in larger regions and in a greater number of the patients than in those without that disease. Although the luxury perfusion and diaschisis phenomena, as well as the influence of cross-over of the count rates between the hemispheres, reduce circulatory time differences, use of the present pertechnetate method allows detection of subtle regional circulatory changes in patients with brain infarction.

Adult↗

PubMed1991

Logical types and ostensive insight.

Discrimination of analogic and digital modes in communication allows clearer distinction of transference (mutative) and extra-transference interpretation. Relying on explicit formulation, Strachey introduces 'implicit' mutative interpretation, which is explicitly extra-transferential but transferential as to process. Each interpretive verbalization has an analogic impact pertaining to the analogic unconscious level of archaic objects, and its emitter--the analyst--is its propositional subject. Interpretation can afford to be as explicit as possible inasmuch as it retains the metalevel in which the analyst can remain as third-party to what he formulates, but it must be gradual in making explicit the archaic object he actualizes. It is by 'withholding'--as Strachey says--the validation of the archaic relational analogic 'psychic reality' that is the referent of interpretive 'mapping', and not be verbal 'mapping' in itself, that the 'judgement of reality' underlying ostensive insight comes into play.

Awareness↗