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K Phillips

Publications and source records attributed to K Phillips.

At least 127 records · Page 7Linked to original sources
PubMed1989

Delta path methods for modeling the effects of multiple selective associations in adoption designs.

In analyses of family data, multiple direct association processes can be modeled by the use of delta path methods derived by Van Eerdewegh (1982), especially the transitivity principle. The method is described for the case of an adoption study involving potential selective matching of adopting parents to two sets of biological parents of adopted offspring in the presence of assortative mating for both wed and unwed couples. Second- and third-order delta paths may be derived by application of the transitivity principle, and these higher-order paths are very convenient in formulating expectations that are due to direct and indirect association processes. Expectations are derived for resemblance among all adults in this three-couple adoption system; examples are given also for deriving parent-offspring expectations to illustrate the general use of higher-order delta paths in structural models of familial resemblance. Matrix notation is employed in order to facilitate the application of the methods in developmental and/or multivariate models.

Adoption↗
PubMed1989

Quantitative genetic analysis of longitudinal trends in adoption designs with application to IQ in the Colorado Adoption Project.

A factor model is presented that provides for either multivariate or developmental specification of longitudinal genetic and environmental effects in the presence of assortative mating and cultural transmission. Delta path methods are employed for the treatment of assortative mating and selective placement effects. The proportions of genetic and environmental variance and covariance attributable to assortative mating and cultural transmission are modeled explicitly. The model was applied to cognitive ability data on 493 families in the Colorado Adoption Project by means of maximum-likelihood pedigree analysis. A test of the assumption of multivariate normality of error provided an additional model criterion beyond the log-likelihood ratio statistic. No significant effects were found for cultural transmission, genetic-environmental covariance, or selective placement. The results suggest that the phenotypic stability of IQ during early childhood is largely, if not entirely, genetic in origin and that these longitudinal genetic effects can be represented most parsimoniously in the form of developmental transmission.

Adoption↗
PubMed1989

Absence of linkage of ABO blood group locus to familial tuberous sclerosis.

A mutation leading to tuberous sclerosis was linked to the ABO blood group locus (9q34) on the long arm of chromosome 9. In an effort to confirm this assignment, nine multigenerational families with tuberous sclerosis, comprising 126 sampled individuals, were assessed for linkage of the ABO locus to tuberous sclerosis. Two-point linkage analysis and multilocus linkage analysis were used to evaluate linkage between tuberous sclerosis and the markers ABO, MCT136, and AblK2. Linkage of ABO to tuberous sclerosis was excluded for a distance of 20 centimorgans (cM) encompassing the region of the ABO locus. There was no evidence for genetic heterogeneity within this data set. Using 23 polymorphic markers, exclusion mapping demonstrated only a 1% probability that the tuberous sclerosis locus was on the distal short arm of chromosome 9 and provided no evidence in support of a tuberous sclerosis locus on the remainder of chromosome 9 including the area of the ABO locus.

ABO Blood-Group System↗
PubMed1989

Evaluation of a rapid method of extracting DNA from stool samples for use in hybridization assays.

The ability of the Extractor system (Molecular Biosystems, Inc., San Diego, Calif.) to isolate nucleic acid (NA) from stool samples for use in hybridization assays was investigated. Crude NA was recovered from 45 of 50 stool samples by using this system. The amount of NA recovered varied considerably depending on the microbial flora present in the sample (mean +/- standard deviation, 50.2 +/- 46.7 micrograms; range, 2 to 228 micrograms) but did not correlate with the consistency of the sample. Samples containing primarily gram-positive organisms or yeast cells gave lower yields of NA (less than 10 micrograms) than those containing gram-negative bacilli. The five samples which did not yield NA were sterile when cultured aerobically on blood agar plates. Samples of the 45 stools yielding NA were inoculated into broth and grown overnight, and a 10-microliters sample of broth was spotted onto nitrocellulose filters. The NA samples recovered from the Extractor column were applied to nylon membranes by using the Centri-dot system. The NA on the broth blots and the NA on the Centri-dot filters were hybridized with a 310-base-pair probe specific for the 2"-O-aminoglycoside adenylyltransferase [ANT(2")] resistance gene. The Extractor-Centri-dot system demonstrated 61.9% sensitivity and 95.8% specificity in detecting the ANT(2") gene in stool samples containing colonies demonstrating the ANT(2") phenotype. The positive and negative predictive values of the NA blot were 92.8 and 74.2%, respectively.

DNA Probes↗
PubMed1989

Is electroencephalographic monitoring of electroconvulsive therapy clinically useful?

Electroencephalographic (EEG) monitoring was carried out in 169 bilateral and 114 unilateral applications of electroconvulsive therapy (ECT), given to 51 patients in an everyday setting within the National Health Service by junior medical staff. In 2.5% of bilateral and 8% of unilateral applications there was disagreement between clinical and EEG assessment as to whether a fit had occurred. When an EEG fit was said to have occurred only if it lasted longer than 25 seconds, then disagreement rose to 7% in bilateral and 28% in unilateral applications; disagreement was higher with unilateral applications, as they produced more short fits than bilateral applications. If future work shows duration of seizure is clearly associated with clinical efficacy, it is suggested the case for routine EEG monitoring is greatly strengthened.

Electroconvulsive Therapy↗
PubMed1989

Linkage analysis in familial amyotrophic lateral sclerosis.

Familial amyotrophic lateral sclerosis (FALS) constitutes 5 to 10% of cases of ALS and, in most families, its inheritance is consistent with an autosomal dominant trait with age-dependent penetrance. The biochemical abnormality underlying the disorder is unknown. We analyzed DNA from 131 members of 6 multigenerational ALS families, which included 13 affected members, for genetic linkage to 39 expressed and DNA markers, using the techniques of 2-point linkage analysis, multilocus linkage analysis, and exclusion mapping. We identified FALS families with structures suitable for linkage, by computer simulation techniques. A DNA bank established to provide optimum use of available FALS families provided DNA from immortalized lymphoblast cell lines and frozen postmortem tissue. We could not link FALS to any of the markers studied, but excluded chromosome regions unlikely to be a locus of the FALS gene. With the help of this exclusion data, we will concentrate on regions of the human genome that remain unexcluded.

Amyotrophic Lateral Sclerosis↗
PubMed1988

Well managed?

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Administrative Personnel↗
PubMed1988

The Nithsdale Schizophrenia Survey. VII. Does relatives' high expressed emotion predict relapse?

A review of all known schizophrenic people living in Nithsdale in South-West Scotland identified long-stay in-patients, patients living on their own and those living with relatives showing low or high expressed emotion (EE). A prospective 12-month follow-up identified relapsing patients, defined as those readmitted to hospital with exacerbation of schizophrenic symptoms or a fresh episode of illness, or, if not readmitted, with a significant increase in antipsychotic medication. There was no difference in relapse rates in patients living on their own, with low-EE, or with high-EE relatives. Amount of contact with high-EE relatives did not affect relapse rates. The different results obtained from the Nithsdale group compared with one from Camberwell are discussed.

Emotions↗
PubMed1987

Path analysis of seven fear factors in adult twin and sibling pairs and their parents.

A multivariate path model of genetic and environmental transmission, used to derive expected covariances among adult twin and sibling pairs and their parents, was fitted to fear factor data from 250 twin families and 91 sibling families, with the use of a maximum-likelihood estimation procedure. The full model, with 259 free parameters, provides for parental cultural transmission, common twin and sibling environment, genotype-environment correlation, direct assortative mating, and genetic and environmental correlations. Significant effects were indicated for heritable transmission of common fears and phobias, and a single genetic factor accounted for most of the genetic covariance among the traits. Moderately high levels of common twin environment and a small effect for direct isomorphic marital assortment were also found. There was no evidence for cultural transmission, genotype-environment correlation, or common sibling environment.

Biometry↗