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S Ennis

Publications and source records attributed to S Ennis.

At least 37 records · Page 2Linked to original sources
PubMed2000

FRAXA and FRAXE: the results of a five year survey.

We report the results of a five year survey of FRAXA and FRAXE mutations among boys aged 5 to 18 with special educational needs (SEN) related to learning disability. We tested their mothers using the X chromosome not transmitted to the son as a control chromosome, and the X chromosome inherited by the son to provide information on stability of transmission. We tested 3738 boys and 2968 mothers and found 20 FRAXA and one FRAXE full mutations among the boys and none among the mothers. This gives an estimated prevalence of full mutations in males of 1 in 5530 for FRAXA and 1 in 23 423 for FRAXE. We found an excess of intermediate and premutation alleles for both FRAXA and FRAXE. For FRAXA this was significant at the 0.001 level but the excess for FRAXE was significant only at the 0.03 level. We conclude that the excess of intermediate and premutation sized alleles for FRAXA may well be a contributing factor to the boys' mental impairment, while that for FRAXE may be a chance finding. We studied approximately 3000 transmissions from mother to son and found five instabilities of FRAXA in the common or intermediate range and three instabilities of FRAXE in the intermediate range. Thus instabilities in trinucleotide repeat size for FRAXA and FRAXE are rare, especially among alleles in the common size range.

Adolescent↗
PubMed1999

The diagnosis of freemartinism in cattle using sex-specific DNA sequences.

The majority of heifers born co-twins to bulls are infertile freemartins. It is important that the condition be diagnosed at an early age as freemartins have no potential for use as replacement stock. A rapid, robust, reliable technique for freemartin diagnosis is described. Three Y-specific polymerase chain reaction (PCR) primer pairs: BOV97M, BRY.1 and AMX/Y were used to detect male cells in the blood of heifers born co-twins to bulls. PCR -based tests have advantages over currently used methods of freemartin diagnosis.

Animals↗
PubMed1997

A medium-density genetic linkage map of the bovine genome.

A cattle genetic linkage map was constructed which covers more than 95 percent of the bovine genome at medium density. Seven hundred and forty six DNA polymorphisms were genotyped in cattle families which comprise 347 individuals in full sibling pedigrees. Seven hundred and three of the loci are linked to at least one other locus. All linkage groups are assigned to chromosomes, and all are orientated with regards to the centromere. There is little overall difference in the lengths of the bull and cow linkage maps although there are individual differences between maps of chromosomes. One hundred and sixty polymorphisms are in or near genes, and the resultant genome-wide comparative analyses indicate that while there is greater conservation of synteny between cattle and humans compared with mice, the conservation of gene order between cattle and humans is much less than would be expected from the conservation of synteny. This map provides a basis for high-resolution mapping of the bovine genome with physical resources such as Yeast and Bacterial Artificial Chromosomes as well as providing the underpinning for the interpolation of information from the Human Genome Project.

Animals↗
PubMed1996

Cloning of the bovine activin receptor type II gene (ACVR2) and mapping to chromosome 2 (BTA2).

The cDNA for the bovine activin receptor type II (ACVR2) gene has been cloned and sequenced. It encodes a protein of 513 amino acids which is highly homologous (approximately 98% identity) to the human, mouse, and rat proteins. Using PCR analysis of bovine x hamster somatic cell lines, the ACVR2 gene was mapped to syntenic group U17, which has been localised to bovine chromosome 2. Comparative mapping has shown that the genes within U17 are also in a syntenic group on the long arm of human and sheep chromosome 2, as well as on mouse chromosome 1. This group of genes represents an evolutionarily conserved mammalian chromosomal segment. Genotyping a highly polymorphic microsatellite locus, (AT)4(GT)9(AT)11, found within an intron of this gene confirmed the localisation by linking the ACVR2-associated microsatellite to the region of chromosome 2 flanked by CSSM42 and TGLA226. This gene locus, which has the characteristics of a type I and type II mapping locus, represents the first localisation of this gene in any species to date.

Activin Receptors↗
PubMed1994

A PCR-based sex-determination assay in cattle based on the bovine amelogenin locus.

A method for determining the sex of bovine embryos has been established. Primers for a portion of the bovine amelogenin locus (AMX/Y) were used to amplify DNA present in either 0.1 microliter of blood or biopsies taken from 6-7-day-old embryos. The primers amplify a 280 bp band in females and a 280 and 217 bp bands in males. The method is rapid, does not require prior purification of DNA and contains an internal control which detects PCR failure.

Amelogenin↗
PubMed1990

Acetazolamide-insensitive carbonic anhydrase activities in liver and tonic skeletal muscle of adult male rats with streptozotocin-induced diabetes mellitus.

One of the four discrete isoenzymes of carbonic anhydrase hitherto characterized, CA III, has the lowest turnover rate and the greatest resistance to inhibition by sulphonamides. Streptozotocin-induced diabetes mellitus resulted in a reduction in acetazolamide-resistant activity of carbonic anhydrase in the liver, but not in tonic skeletal muscle, of adult male rats. The hepatic activity declined with apparent first-order kinetics [calculated rate constant (k) 0.089 day-1] to a minimum of approx. 6% of control values; the reduction in activity was moderated by administration of insulin.

Acetazolamide↗
PubMed1986

Differentiated retinal Müller glia are ciliated--ultrastructural evidence in the teleost Poecilia reticulata P.

It is generally held that the cells in all retinal layers bear a cilium during development but there have been controversial reports as to whether the ciliation of the Müller cell persists after birth. The present study of the developing and fully formed adult eye of the teleost Poecilia reticulata reveals that just prior to the formation of the photoreceptors in the embryonic retina, the Müller cell contains only a diplosome. Throughout development the diplosome is seen to migrate apically, always juxtaposed to many microtubules. When the photoreceptors are differentiated and capable of photomechanical movement, the Müller cell in Poecilia bears a cilium situated vitreally to the external limiting membrane. The cilium persists in juvenile and adult retinae in both the light- and dark-adapted state. The functional significance of the cilium in the Müller cell is presently unknown.

Animals↗
PubMed1984

Myeloid bodies in the pigment epithelium of a teleost embryo, the viviparous Poecilia reticulata.

Appearance of myeloid bodies (MB) in the retinal pigment epithelium (RPE) precedes photoreceptor outer segment development in Poecilia reticulata embryos reared under a 12 hrs LD cycle, in constant darkness (DD) and constant light (LL). When first formed, MB are predominantly continuous with rough endoplasmic reticulum (RER). The same is observed in the peripheral growth zone of the developed eye, whereas in differentiated parts, MB are continuous with the smooth endoplasmic reticulum (SER). At onset of photomechanical movements, wavy MB predominate in light-adapted LD embryos, are exclusively present in LL and are located in the RPE processes. SER abounds. Straight MB predominate in dark-adapted LD embryos, are exclusively present in DD and contain electrondense material between lamellae. Diurnal appearance of electrondense material may be coupled with transfer of retinol, mediated by various transport proteins.

Age Factors↗
PubMed1983

Ontogeny of the photoreceptors in the embryonic retina of the viviparous guppy, Poecilia reticulata P. (Teleostei). An electron-microscopical study.

Ultrastructural analyses of retinal development in the guppy embryo show that at midgestation all types of photoreceptors are differentiated in the fundus, and at birth differentiation extends over the whole retina. Formation of discs of outer segments is more rapid in rods than in cones. Double cones differentiate simultaneously with long single cones and are formed by the adhesion of two primordial inner segments; short single cones develop last. Wherever cones are differentiated, they are arranged in an adult-type square mosaic. The rods in the embryo, as opposed to the adult, are likewise regularly arranged within the mosaic unit. These results are at variance with the generally held opinion that adult teleosts which possess duplex retinae have larvae with pure cone retinae, and that rods, double cones and mosaics appear in late larval life or only at metamorphosis. In the double cones of the guppy embryo subsurface cisternae develop along the adjoining primordial inner segments. Additionally, regularly distributed subsurface cisternae are formed in the regions of intimate contact of long single cones with double cones and rods. We suggest that the early development of rods and double cones, and a square-mosaic with regular distribution of rods and subsurface cisternae, provide the newly born with a fully functional optical apparatus, especially suited to perception of movements. This is necessary for its survival against predatory, especially maternal, attacks.

Animals↗
PubMed1983

Ultrastructural diurnal changes of the retinal photoreceptors in the embryo of a viviparous teleost (Poecilia reticulata P.).

All diurnal changes studied - ellipsosome excepted - start at midgestation, following differentiation of photoreceptors and pigment-epithelium cells. These are: (1) shedding of the tips of the light-sensitive photoreceptor outer segments and subsequent phagocytosis by the pigment-epithelium; (2) retinomotor movements of pigment-epithelium processes, rods and cones; (3) changes of cone square-mosaics into row-mosaics at night. Newly-differentiated photoreceptors in the embryo are, therefore, already vulnerable to disruption of cyclical systems. Several inherited human retinal diseases, such as Retinitis pigmentosa, are thought not to affect differentiation of photoreceptors but their cyclical renewal pathways. The retina of the guppy-embryo is, therefore, a valuable model for such studies.

Animals↗
PubMedDate not supplied

The feasibility of a telecommunications service in support of outpatient congestive heart failure care in a diverse patient population.

A home telemonitoring system for patients with congestive heart failure was studied for feasibility and efficacy in a diverse patient population. Fifty patients used the service, in which they weighed themselves and answered yes/no questions about symptoms. Changes in patient weights or symptoms prompted a nurse to call the patient and/or the physician. Patients were given educational and quality of life surveys at enrollment, at 30 days, and at 6 months. The average daily usage rate was 94%. Patients were contacted 57 times--prompting 57 physician notifications, eight medication changes, and 11 nonroutine clinic visits. Patient response to lifestyle surveys showed an improvement in quality of life and improved understanding of prevention measures. Eighty-four percent of patients and 65% of physicians reported satisfaction with the system. This pilot study suggests that home telemonitoring is feasible and has clinical utility in diverse patient groups, and may improve patients' satisfaction and knowledge of self-care. (c)2000 by CHF, Inc.

Journal Article↗