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Biomedical subjects

A Robinson

Publications and source records attributed to A Robinson.

At least 307 records · Page 17Linked to original sources
PubMed1990

[Crush injuries].

Explore the source record for details and available documents.

Crush Syndrome↗
PubMed1990

Interactions of signal peptides with signal-recognition particle.

The mechanisms whereby isolated or synthetic signal peptides inhibit processing of newly synthesized prolactin in microsome-supplemented lysates from reticulocytes and wheat-germ were investigated. At a concentration of 5 microM, a consensus signal peptide reverses the elongation arrest imposed by the signal-recognition particle (SRP), and at higher concentrations in addition inhibits elongation of both secretory and non-secretory proteins. A photoreactive form of a synthetic signal peptide cross-links under u.v. illumination to the 54 kDa and 68 kDa subunits of SRP, whereas the major cross-linked protein produced after photoreaction of rough microsomes is of 45 kDa. As SRP-mediated elongation arrest is unlikely to be essential for translocation, it is suggested that signal peptides may interact with components other than SRP in the translation system in vitro.

Animals↗
PubMed1990

Growth and siderophore production by Bordetella pertussis under iron-restricted conditions.

It has been demonstrated that under iron-restricted conditions Bordetella pertussis can obtain iron from iron-saturated human transferrin. Direct contact between B. pertussis and transferrin was not required as B. pertussis was able to acquire iron from transferrin when they were separated by a dialysis membrane. Siderophore activity was detected in supernatants from iron-restricted cultures of B. pertussis, B. bronchiseptica and B. parapertussis. Siderophores were identified as hydroxamates and were produced by both virulent and avirulent strains of B. pertussis.

Bordetella pertussis↗
PubMed1990

Analysis of non-disjunction in sex chromosome tetrasomy and pentasomy.

X-linked DNA markers were used to determine the parental origin of the additional sex chromosomes in eight individuals with sex chromosome tetrasomy or pentasomy. In all cases studied, one parent contributed a single sex chromosome while the other parent contributed three or four sex chromosomes. Thus, it seems likely that most, if not all, sex chromosome tetrasomy and pentasomy is attributable to successive non-disjunctional events involving the same parent.

Female↗
PubMed1990

Stimulation of proteolysis on calmodulin.

The proteolysis of calmodulin by fungal protease (type XIX) was greatly enhanced in the presence of dGTP and MS2 RNA. Whereas, only moderate proteolytic activation on bacterial proteases (type XXVI) was observed in the presence of MS2 RNA. No appreciable proteolysis of calmodulin by bacterial protease (type IX) was observed. Proteolytic fragments of calmodulin cleaved by fungal protease exhibited unusual low mobility during SDS-polyacrylamide gel electrophoresis. Similar decreased electrophoretic mobility was also noted in the proteolytic fragments of other Ca2(+)-binding proteins including S-100A protein and parvalbumin.

Animals↗
PubMed1990

Recognition of pertussis toxin by antibodies to synthetic peptides.

Eight synthetic peptides, selected from the amino acid sequence of pertussis toxin (PT) subunits S1, S2, S3 and S4, were assessed for their ability to induce protein-recognizing and neutralizing antibodies. Seven of these peptides, prepared as conjugates of either keyhole limpet haemocyanin or tetanus toxoid, induced significant levels of antibody, all of which reacted with SDS-denatured PT on Western blots. Six of the antibodies bound to PT-coated ELISA plates; this binding was inhibited by homologous peptide antigen. However, none of the antibodies, including those directed against the N-terminus of subunit S1, were able to attenuate in vivo or in vitro toxin-dependent activity. Further investigation revealed that only one antibody, specific for the C-terminus of S1 (peptide Slc, 237-255), could recognize the conformation of native PT in solution. The other five antipeptide antibodies which reacted with PT-coated ELISA plates did not recognize PT when captured onto ELISA plates via either a monoclonal antibody or fetuin, unless the conformation of the toxin had been relaxed by reduction with dithiothreitol. Conversely, the native PT-recognizing response of peptide Slc did not bind the conformationally relaxed PT molecule. From this study, it appears likely that a peptide capable of inducing PT-neutralizing antibody must closely resemble the conformation of the cognate sequence in the native protein.

Amino Acid Sequence↗
PubMed1990

The signal sequence of the p62 protein of Semliki Forest virus is involved in initiation but not in completing chain translocation.

So far it has been demonstrated that the signal sequence of proteins which are made at the ER functions both at the level of protein targeting to the ER and in initiation of chain translocation across the ER membrane. However, its possible role in completing the process of chain transfer (see Singer, S. J., P. A. Maher, and M. P. Yaffe. Proc. Natl. Acad. Sci. USA. 1987. 84:1015-1019) has remained elusive. In this work we show that the p62 protein of Semliki Forest virus contains an uncleaved signal sequence at its NH2-terminus and that this becomes glycosylated early during synthesis and translocation of the p62 polypeptide. As the glycosylation of the signal sequence most likely occurs after its release from the ER membrane our results suggest that this region has no role in completing the transfer process.

Amino Acid Sequence↗
PubMed1990

Efficacy of bomb shelters: with lessons from the Hamburg firestorm.

Shelters for protection against the effects of nuclear weapons are often stated to be useless, largely because of firestorms. Recent models purport to show that nuclear weapons are more likely to cause firestorms than previously thought. These controversial models are based on uncertain assumptions, which are difficult or impossible to test. Regardless of the predictive validity of fire models, conclusions about the ability of shelters to protect their occupants against firestorms, if they occur, are based primarily on historical experience. A review of the original data from the Hamburg firestorm shows that almost all persons in adequate shelters survived, contradicting a currently prevailing belief that all died. The results of the strategic bombing during World War II and of nuclear weapons tests show that a considerable level of population protection can be achieved through attention to proper shelter design.

Burns↗
PubMed1990

Antisperm antibodies and lymphocyte subsets in semen--not a simple relationship.

The significance of white blood cells in the ejaculate remains a matter of controversy. Several authors have suggested that such cells are important in the modulation of an antisperm antibody response, i.e. a predominance of suppressor/cytotoxic to helper/inducer T cells may prevent the development of antisperm antibodies. In order to examine this relationship further we have documented the white blood cell types, with emphasis on the T-lymphocyte populations, in the ejaculates of men from infertile couples with and without antisperm antibodies; the latter group was divided further into two groups--vasovasostomized men and idiopathic men. All seven of the men without antisperm antibodies had a predominance of suppressor/cytotoxic T cells to helper/inducer T cells in the ejaculate. However, only in some of the men with antibodies was there a predominance of T-helper/inducer cells. It is clear that the relationship between antisperm antibodies and seminal leucocytes is therefore not as straightforward as has been proposed.

Antibodies↗
PubMed1990

Seminal peroxidase positive cells are not an adequate indicator of asymptomatic urethral genital infection.

The relationship between asymptomatic urethral infection and seminal white blood cells, as detected using the peroxidase enzyme system, was examined. Eighty-four semen donors were tested. Twenty-four (29%) were diagnosed as having an active urethral genital infection. There was no statistical relationship between the total number of concentrations of peroxidase-positive cells and a urethral genital infection. Further studies should concentrate on the subtypes of seminal leucocytes and their surface receptors using monoclonal antibodies.

Humans↗
PubMed1990

Sexually transmitted diseases in rape victims.

From 1 January 1986 to 1 September 1989 124 women presented to the Ambrose King Centre (the department of genitourinary medicine of the London Hospital) alleging rape. Sexually transmitted diseases were found in 36 (29%) women (excluding candidosis and bacterial vaginosis). The commonest organisms detected were Neisseria gonorrhoeae and Trichomonas vaginalis, each being present in 15 patients. Eleven women had genital warts. Chlamydia trachomatis was isolated in six patients, two had herpes simplex virus infection and one patient had pediculosis pubis. Serological evidence of past hepatitis B infection was detected in five women and one patient had antibodies to human immunodeficiency virus. Eighteen of the 36 women (50%) had multiple infections. Six women had abnormal cervical cytology smears, three being suggestive of cervical intraepithelial neoplasia grades II-III. Although it is rarely possible to attribute infection to an assailant, these patients require further counselling, treatment and review. Rape victims are thus a population at risk of having sexually transmitted diseases and screening should be offered.

Adolescent↗