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R Dodd

Publications and source records attributed to R Dodd.

29 records · Page 2Linked to original sources
PubMed1988

Chorionic gonadotrophin-beta mRNA, a trophoblast marker, is expressed in human 8-cell embryos derived from tripronucleate zygotes.

Human chorionic gonadotrophin beta (HCG-beta) is a trophoblast marker. Its expression is normally limited to syncytiotrophoblast cells of chorionic villi, although it is known to be secreted from the human embryo as early as 7 days post-fertilization. To examine the onset of embryonic transcriptional activity of the gene encoding this polypeptide we have performed in-situ hybridization to cellular RNAs of human tripronucleate preimplantation embryos. We see expression of HCG-beta RNA at the 6-8-cell stage, before morphological differentiation between trophectoderm and inner cell mass is apparent. We believe that this RNA is the product of de novo transcription from the embryonic genome, since transcripts are only observed in embryos of at least 2 days post-fertilization in age.

Blastocyst↗
PubMed1985

Visualization by positron emission tomography of the apparent regional heterogeneity of central type benzodiazepine receptors in the brain of living baboons.

The feasibility of visualizing the heterogeneity of benzodiazepine (BDZ) receptors in the brain of living baboons was investigated using Positron Emission Tomography. Ethyl 8-fluoro-5,6-dihydro-5-methyl 6-oxo-4H-imidazo (1,5-a) (1, 4) benzodiazepine-3-carboxylate (RO 15 1788) labelled by carbon 11 (11C-RO 15 1788) was I.V. injected for the "in vivo" labelling of the central type BDZ receptors. Displacement experiments were performed 20 minutes after the administration of the radioligand by two different cold drugs: RO 15 1788 which has an equal affinity for central type BDZ receptors, and propyl B-Carboline-3-carboxylate (B-CCP) which favours the sites located in the cerebellum. Different sensitivities to these two drugs displacement of 11C-RO 15 1788 binding "in vivo" were observed: on the one hand in the regional localization of the displacement, and on the other hand, in the amount of the radioactivity displaced. The apparent interregional heterogeneity of the displacement seen in the cerebellum and in the temporal cortex are discussed in terms of discrepancies observed "in vitro" at physiological temperature, between cerebellar and non-cerebellar BDZ central type binding sites.

Animals↗
PubMed1984

[Potent convulsant effects of a benzodiazepine inverse agonist, methyl beta-carboline-3-carboxylate in cats].

The convulsant properties of methyl beta-carboline-3-carboxylate (beta-CCM), which is a homologue of a putative benzodiazepine receptor ligand in the mammalian central nervous system, were examined in cats. Subcutaneous injection of 0.5 mg/kg of the beta-CCM produced various degrees of myoclonic jerks always accompanied by cortical spike burst. Some autonomic symptoms such as tachypnea, hypersecretion of thick mucous saliva, vomiting and mydriasis were also presented. Subcutaneous injection of 1.0 mg/kg of the compound induced a generalized tonic-clonic convulsion. Injection of the same amount of the drug 1 hour later in the same cats failed to provoke a generalized seizure. Repeated injection of the same dose 3 hours later provoked a generalized seizure, but with a longer latency. However, repetition of the experiments 24 hours after or 10 days after the first injection consistently induced the same type of generalized seizure with the same latency as the first injections. These results support the suggestion that the pharmacological effect, especially the convulsive effect, of beta-CCM is dose-related, reversible and reproducible in the same cats and among different cats. Moreover, the postictal refractory period in this model of epilepsy may continue about for 3 hours.

Animals↗
PubMedDate not supplied

Methodologic approaches to surveillance of HIV infection among blood donors.

Blood donors make up the largest group in the United States that is tested for human immunodeficiency virus, type 1 (HIV) antibody. The blood donor population is ideal for detecting and quantifying uncommon or unrecognized modes of HIV transmission in the general population because persons at known risk for HIV infection are excluded from donating blood. The national HIV surveillance program consists of a centralized computer database of information on all donations at selected American Red Cross blood centers, which together account for about a quarter of the blood supply, and all donations at 20 regional blood centers where seropositive blood donors are interviewed to evaluate their risk factors for HIV infection and to determine their epidemiologic characteristics and motives for donation. Trends in HIV prevalence and incidence within specific demographic subgroups are determined for first-time and repeat donors. Combining the trends with HIV-risk profile data from seropositive donors provides a rate for HIV seropositive donors with no identified risk. Epidemiologic and behavioral data from seropositive donors will help in the development and evaluation of future donor deferral strategies.

Blood Banks↗