PubMed Health⌕ Search

Biomedical subjects

J A Robertson

Publications and source records attributed to J A Robertson.

At least 19 recordsLinked to original sources
PubMed1992

Legal and ethical issues arising with preimplantation human embryos.

The development of in vitro fertilization has led to ethical and legal controversies concerning actions with externalized preembryos. A legal and ethical consensus is emerging that preembryos are not legal persons or moral subjects, although they are owed special respect because of their ability to implant and come to term. In addition, gamete providers are recognized as having dispositional authority over whether preembryos will be created, cryopreserved, placed in a uterus, discarded, donated, or used in research. Prior agreements over preembryo disposition are the best way to minimize disputes between the gamete providers.

Embryo Transfer↗
PubMed1992

Legal and ethical issues arising from the new genetics.

Legal and ethical issues involving genetics arise at the level of carrier screening, preimplantation diagnosis in embryos and prenatal diagnosis in fetuses. A strong commitment to procreative liberty and autonomy should permit patients and physicians to gain access to genetic information at every stage of decision making. Even if Roe v Wade is reversed, considerable room for the use of genetic information in procreative decision making will remain.

Decision Making↗
PubMed1991

Genome sizes of mammalian and avian Ureaplasmas.

The sizes of the genomes of 12 Ureaplasma strains isolated from six mammalian and one avian species, as determined by pulsed-field gel electrophoresis, varied from 760 to 1,170 kilobase pairs (470 to 723 megadaltons); and these values encompassed the values for the genomes of Ureaplasma urealyticum strains. Variation of at least 54% in the genome sizes restricts the usefulness of this taxonomic criterion for the genus Ureaplasma.

Animals↗
PubMed1991

Hemadsorption by colonies of Ureaplasma urealyticum.

Hemadsorption by colonies of Ureaplasma urealyticum and Mycoplasma pneumoniae differed quantitatively and qualitatively. Using standard methodology, few strains of U. urealyticum hemadsorbed; with a modified method, most strains hemadsorbed, indicating a second type of association. Scanning electron microscopy of tannin-osmium-stained preparations showed guinea pig erythrocytes embedded in ureaplasma colonies and craters left when erythrocytes were dislodged.

Animals↗
PubMed1991

Clinical and biological characteristics of Ureaplasma urealyticum induced polyarthritis in a patient with common variable hypogammaglobulinaemia.

Persistent infectious polyarthritis caused by Ureaplasma urealyticum in a patient with common variable hypogammaglobulinaemia is described. The patient developed a symmetrical, destructive polyarthritis and tenosynovitis associated with a markedly depressed synovial fluid glucose concentration and characteristic soft tissue abscesses. The ureaplasma organism developed resistance to multiple antibiotics and persisted for five years. The organism was identified repeatedly in many joints by culture, confirmed by DNA hybridisation, and mycoplasma-like structures were shown in synovial tissues by electron microscopy.

Adult↗
PubMed1991

Case management.

"This paper discusses the advantages and disadvantages of case management systems for the co-ordination of care of people with long-term mental illness living in the community. Many of the principles are equally applicable to other client groups with long-term needs, e.g. elderly people or people with learning difficulties. Some of the historical background to the emergence of case management concepts is discussed, culminating in the recent White Paper on Community Care. The underlying concept of case management is examined, together with a number of fundamental questions concerning who should act as case managers, what kinds of training they will require, problems of inter- and intra-agency co-operation, and the empirical evidence regarding its effectiveness. It is concluded that case management could be an important element in a comprehensive range of mental health services, but it is not a substitute for basic community provisions."

Community Mental Health Services↗
PubMed1990

Human ureaplasmas show diverse genome sizes by pulsed-field electrophoresis.

Contour clamped homogeneous field (CHEF) agarose gel electrophoresis (AGE), ramped to give linear separation of DNA molecules of 600-1600 kilobase pairs (kbp), was used to determine mobilities for full-sized genomic DNA of the serotype standard strains of the human genital mollicutes, Ureaplasma urealyticum relative to yeast chromosomal DNA markers. Indicated genome sizes (in kbp) were 760 for the four biotype 1 strains and 840-1140 for eleven biotype 2 strains. Other estimates were: 720 for Mycoplasma hominis, 1070 for Mycoplasma hyopneumoniae, 890 for Mycoplasma flocculare, 1180 and 1350 for Mycoplasma mycoides subsp. mycoides Y and GC1176-2, respectively, and 1650 and 1580 for Acholeplasma laidlawii B and PG 8, respectively. These data supplement previous evidence from CHEF AGE that the genomes of the Mycoplasmataceae are diverse in size with some larger than previously estimated from DNA renaturation kinetics.

DNA, Bacterial↗
PubMed1990

The growth response of Mycoplasma hyopneumoniae and Mycoplasma flocculare based upon ATP-dependent luminometry.

Cultures of Mycoplasma hyopneumoniae and M. flocculare in Friis' broth grew faster and to higher titers in air than in 8% CO2; cultures in air grew better when shaken than when stationary. Under the optimal conditions, both species have generation times of about 10 h and achieve maximum titers of at least 10(9) organisms per ml. Maximum growth was reached near pH 7.0, before the phenol red indicator had noticeably changed colour. Changes in growth were readily detected by an ATP assay based upon the luciferin-luciferase reaction. Concentrations of ATP fell rapidly after peak growth. Although the addition of 27 mM glucose to the medium did not change the pattern of growth and gas chromatography gave no evidence of the production of volatile or non-volatile end-products, washed harvested cells of both species metabolized [14C]-glucose. The addition of 29 mM arginine to the medium inhibited growth.

Adenosine Triphosphate↗
PubMed1990

Structural and regulatory analysis of the male-specific rat liver cytochrome P-450 g: repression by continuous growth hormone administration.

Complementary DNA clones encoding the male-specific rat liver cytochrome P-450 g have been isolated by cross-hybridization with sequences from the female-specific rat liver cytochrome P-450 15 beta. Tissue distribution analysis indicates the liver as the organ with major expression of this cytochrome P-450 gene. Minimal P-450 g expression was also detected in prostate, kidney, heart, and brain. A developmental analysis reveals liver expression in the 8-week-old male and to a lesser extent in the 4-week-old male, but no detectable expression is seen in females of these ages or in 1- and 2-week-old rats from both sexes. Hypophysectomy of female rats dramatically increases hepatic expression of P-450 g, whereas continuous GH administration represses hepatic expression in male or female hypophysectomized rats. In similarity to P-450 15 beta and P-450 16 alpha, therefore, the cytochrome P-450 g gene in liver is GH regulated.

Amino Acid Sequence↗
PubMed1990

Growth hormone pretranslationally regulates the sexually dimorphic expression of the prolactin receptor gene in rat liver.

The female-specific expression of the rat liver PRL receptor (PRL-R) gene was investigated by Northern analysis of hypophysectomized rats after two alternative human GH treatments that were to mimic either 1) the continuous female-specific or 2) the discontinuous male-specific serum GH patterns. The former (female-specific) pattern was shown to result in a dramatic increase in PRL-R mRNA in both males and females, while the latter (male-specific) pattern failed to evoke this response. A similar inductive effect in hypophysectomized females was shown after continuous administration of bovine GH and was found to constitute an approximately 60-fold increase in PRL-R mRNA levels. This effect by bovine GH, which, unlike the human isoform, is devoid of lactogenic properties, thus indicates the somatogenic origin of the signal resulting in this inductive response. These observations in conjunction with previous data obtained for other GH-regulated nonreceptor genes are interpreted to support the proposal of GH serum patterns being an early signal in a more general mechanism for pretranslational regulation of sex-specific gene expression. In contrast to GH, only a slight elevation of PRL-R mRNA was evoked by the ligand ovine PRL, while coadministration of ovine PRL with bovine GH failed to enhance the mRNA level found with bovine GH alone. The detection of previously unreported PRL-R mRNAs in liver of approximately 3.0, 3.8, and 5 kilobases in addition to the major 2.2-kilobase form was also evident after continuous GH administration.

Animals↗