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Biomedical subjects

M Robertson

Publications and source records attributed to M Robertson.

At least 181 records · Page 10Linked to original sources
PubMed1985

Macroaggregate formation in optimal additive red cells.

The formation of macroaggregates weighing up to 9 g was observed in optimal additive red cells. Such aggregates, with a mean wet weight of 3 g, formed progressively during storage and were present in up to 85% of units. They were composed of leucocyte and platelet debris, together with some fibrin. Macroaggregates formation was halved by less stringent centrifugation during preparation and was reduced by use of an optimal additive system in which the additive solution contained citrate. Extra mixing during transfer of the additive solution only delayed aggregate formation. Partial leucocyte depletion or addition of 200,000 KIU of the enzyme inhibitor aprotinin did not prevent macroaggregate formation.

Blood Preservation↗
PubMed1984

A clinical study of Gilles de la Tourette syndrome in the United Kingdom.

The clinical features of 53 British-born patients with Gilles de la Tourette syndrome are described. The mean age at onset of body tics was seven years and for vocalisations 11 years. Coprolalia was present in 39%, copropraxia in 21%, echolalia in 46% and echopraxia in 21%. Complicated antics and mannerisms were also common, often involving the compulsive touching of objects or self-injurious behaviour. Forty-six per cent of cases had a family history of tics in a single close relative and in two individuals a further member of the family had Gilles de la Tourette syndrome. Focal dystonia was present in four patients who had never received neuroleptics drugs and chorea was seen in two other untreated patients. In three patients acoustic startle consistently induced brief eye blink followed by a whole body jerk or jump. Rapid repetitive movements of the hands increased the frequency and severity of tics in 13 patients, but the performance of mental arithmetic under time pressure had a much more unpredictable effect. Electroencephalographic abnormalities occurred in eight (13%) but no definite CT brain scan abnormalities were detected. The incidence of left handedness did not differ from that in the general population and no evidence to suggest organic impairment was found on neuropsychological testing. This study provides no support for the notion that Gilles de la Tourette syndrome is a degenerative disorder of the central nervous system but provides some evidence for heterogeneity.

Adolescent↗
PubMed1984

Multiple sclerosis in a Glasgow tenement.

Two males and two females brought up in the same Glasgow tenement later developed multiple sclerosis. Two of the four, a brother and sister, owned a dog who died of distemper when they were respectively eight and 12 years old.

Adolescent↗
PubMed1983

The external transcribed spacer and preceding region of Xenopus borealis rDNA: comparison with the corresponding region of Xenopus laevis rDNA.

We report sequence data from a cloned rDNA unit from Xenopus borealis, extending leftwards from the 18S gene to overlap a region previously sequenced by R. Bach, B. Allet and M. Crippa (Nucleic Acids Research 9, 5311-5330). Comparison with data from other species of Xenopus leads to the inference that the transcription initiation site in X.borealis is in the newly sequenced region and not, as was previously thought, in the region sequenced earlier. The X.borealis external transcribed spacer thus defined is some 612 nucleotides long, about 100 nucleotides shorter than in X.laevis. The X.borealis and X.laevis external transcribed spacers show a pattern of extensive but interrupted sequence divergence, with a large conserved tract starting about 100 nucleotides downstream from the transcription initiation site and shorter conserved tracts elsewhere. The regions in between the conserved tracts differ in length between the respective external transcribed spacers indicating that insertions and deletions have contributed to their divergence, as previously inferred for the internal transcribed spacers. Much of the overall length difference is in the region flanking the 18S gene, where there are also length microheterogeneities in X.laevis rDNA. As in X.laevis, the transcribed spacer sequences flanking the 18S gene in X.borealis contain no major tracts of mutual complementarity. The accumulated data on transcribed spacers in Xenopus render it unlikely that processing of ribosomal precursor RNA involves interaction between the regions flanking 18S RNA.

Animals↗
PubMed1983

Secretion of rat placental lactogen by the fetal placenta and its inhibitory effect on prolactin surges.

The various products of conception were examined for their ability to secrete rat placental lactogen (rPL), cause normal termination of the diurnal and nocturnal prolactin (Prl) surges and maintain progesterone secretion. Serum rPL, highest on Day 12, was measured by Nb2 lymphoma cell bioassay. Surgery was performed on Day 8, leaving only the uterus in aborted animals, the decidua in the decidua intact animals, or the placenta and decidua in the fetectomized animals. In control rats, rPL levels were elevated by the afternoon of Day 8, the last day the diurnal Prl surge is seen. By Day 10, the last day of the nocturnal surge, rPL levels were extremely high. Fetectomized animals exhibited both the diurnal and nocturnal surges for 2 additional days while rPL secretion was only slightly above baseline levels. Both the decidua-intact and aborted animals continued both daily Prl surges with barely detectable rPL levels. Progesterone secretion was maintained through Day 14 only in the control animals. It is concluded the rPL is secreted by the fetal trophoblastic cells, not the decidua, and that the presence of the fetus is necessary for secretion of normal amounts of rPL and maintenance of pregnancy. Further support is given to the hypothesis that it is rPL which terminates the Prl surges at midpregnancy.

Animals↗
PubMed1983

U1 small nuclear RNA genes are located on human chromosome 1 and are expressed in mouse-human hybrid cells.

The majority, and perhaps all, of the genes for human U1 small nuclear RNA (U1 RNA) were shown to be located on the short arm of human chromosome 1. These genes were mapped by Southern blot analysis of DNA from rodent-human somatic cell hybrids, using the 5' region of a human U1 RNA gene as a human-specific probe. This probe hybridized to DNA fragments present only in digests of total human DNA or to the DNAs of cell lines which contained human chromosome 1. The major families of human U1 RNA genes were identified, but some human genes may have gone undetected. Also, the presence of a few U1 RNA genes on human chromosome 19 could not be ruled out. In spite of the lack of extensive 5'-flanking-region homology between the human and mouse U1 RNA genes, the genes of both species were efficiently transcribed in the hybrid cells, and the U1 RNAs of both species were incorporated into specific ribonucleoprotein particles.

Animals↗
PubMed1983

Schizophrenic psychosis associated with aqueduct stenosis in adults.

The case histories of five adult patients with hydrocephalus and aqueduct stenosis are presented. All the cases were associated with prominent psychotic symptoms (delusions, hallucinations or thought disorder). In the three cases where operative intervention was carried out the diagnosis was made in adult life. Using the Present State Examination all five cases were classified as having schizophrenic psychosis. The possible reasons for this association are discussed.

Adolescent↗
PubMed1982

Inverse relationship of prolactin and rat placental lactogen during pregnancy.

Serum prolactin, progesterone and rat placental lactogen (rPL) were measured in pregnant rats following removal of various numbers of conceptuses and their placentas on Day 8 of pregnancy. Blood samples were taken during the time of the expected nocturnal surge of prolactin on Days 8 and 9, and at the same time on Days 11 and 14 of pregnancy, when the surges are normally no longer present. As the number of conceptuses present decreased, the number of days the prolactin surge was present increased. Measurement of the early form of rPL (rPL-I) by lymphoma cell bioassay revealed a proportionate decrease in serum rPL-I levels on Days 9 and 11 as the number of conceptuses was decreased. This also was true for the late form of rPL (rPL-II) when measured by RIA on Day 14 of pregnancy. Thus, as rPL levels are reduced, prolactin surges remain present for increased numbers of days. This suggests that rPL may normally be an inhibitory factor to prolactin secretion during pregnancy, and is responsible for the termination of the prolactin surges at midpregnancy.

Animals↗