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Biomedical subjects

K Manchester

Publications and source records attributed to K Manchester.

17 recordsLinked to original sources
PubMed1998

An alpha subunit-deficient form of eukaryotic protein synthesis initiation factor eIF-2 from rabbit reticulocyte lysate and its activity in ternary complex formation.

Eukaryotic protein synthesis initiation factor eIF-2 is usually isolated as a heterotrimer (alphabeta gamma). By use of Sephacryl S-300 fractionation an alpha subunit-deficient form of eIF-2 was identified in impure preparations from rabbit reticulocyte lysate and it appeared in these preparations to be still active in formation of the ternary complex (eIF-2.GTP.Met-tRNAi). Subsequently alpha subunit-deficient eIF-2 was further purified and this appeared to have retained ternary complex forming activity. Together with a suggested lack of involvement of the beta subunit this implies that the alpha subunit was not required for activity and the gamma subunit bound both GTP and Met-tRNAi in formation of the ternary complex. The identification and study of alpha subunit-deficient eIF-2 thus elucidated the involvement of the subunits in binding of GTP and Met-tRNAi to produce the ternary complex in polypeptide chain initiation.

Animals↗
PubMed1997

The quest by three giants of science for an understanding of cancer.

Understanding the causes of cancer remains a major area of uncertainty, and many serious proposals have been made from a variety of standpoints over the years. This article discusses the first genetic hypothesis from the turn of the century and two other totally different early approaches to the problem.

Biochemistry↗
PubMed1995

Maxillary sinusitis in Medieval Chichester, England.

Maxillary sinusitis is a common medical complaint, affecting more than 30 million people per year in the United States alone. Very little palaeopathological work on this disease has been carried out, probably because of the enclosed nature of the sinuses in intact skulls and the lack of a suitable method for examination. This study tested the hypothesis that maxillary sinusitis was more common in people with leprosy than in people without it in Medieval England. The prevalence of maxillary sinusitis by age and sex was recorded in 133 individuals, some diagnosed as being leprous, derived from a later Medieval (12th to 17th centuries AD) urban hospital population at Chichester, Sussex, England using both macroscopic and endoscopic methods of examination. Of the 133 individuals with one or both sinuses available for examination, 54.9% (73) had evidence of bone change within the sinuses. There was no difference in prevalence between those with leprosy and those without, although clinical studies suggest that over 50% of lepromatous leprous individuals may develop sinusitis. Comparison with another study on Medieval British sites with a 3.6% prevalence (3 of 83) indicates that the prevalence at Chichester is much greater. The problems with diagnosing sinusitis are addressed and reasons behind the high frequency in this study are discussed. Aetiological factors predisposing to maxillary sinusitis are considered with reference to possible environmental conditions prevailing in the later Medieval period in Britain.

Bone and Bones↗
PubMed1995

Comparative study of the prevalence of maxillary sinusitis in later Medieval urban and rural populations in northern England.

Six hundred sixty-three Medieval individuals from Wharram Percy, a rural settlement in the Yorkshire Wolds, and 1,042 individuals from St. Helen-on-the-Walls, a poor parish in the Medieval city of York, were examined in order to test the hypothesis that maxillary sinusitis would be more prevalent in an urban population due to social and environmental conditions characteristic of an industrialized settlement. The results showed that the individuals from St. Helen-on-the-Walls, living in the urban environment, had a greater prevalence of maxillary sinusitis than the rural population; 39% (106) of the individuals from Wharram Percy had evidence of sinusitis compared to 55% (134) of the individuals from St. Helen-on-the-Walls. It is suggested that this pattern may be attributed to occupation and industrial air pollution in the Medieval city of York.

England↗
PubMed1995

Prevalence of maxillary sinusitis in leprous individuals from a medieval leprosy hospital.

The maxillary sinuses of 133 skeletons from the medieval hospital of St. James and St. Mary Magdalene, Chichester, England, were analyzed for evidence of sinusitis. Of the sample, 16 individuals were considered to have suffered from lepromatous leprosy and 13 from tuberculoid leprosy. The most common bone change seen within the sinuses was the presence of new bone formation followed by pitting. Bone change was seen in 56.3% (9 of 16) of the individuals with lepromatous leprosy and 54.8% (57 of 104) of nonleprous individuals. These results are not statistically significant. Clinical evidence suggests that one should see a higher frequency in the lepromatous group. Possible explanations of this include environmental factors promoting the spread of droplet infection in an immunosuppressed community, in addition to which the small sample of leprous skeletons may bias the result.

Adult↗
PubMed1995

Inflammatory bone changes in leprous skeletons from the medieval Hospital of St. James and St. Mary Magdalene, Chichester, England.

The extent and location of an inflammatory bone lesion, periostitis, were examined in 50 leprous skeletons from the Chichester cemetery of the Hospital of St. James and St. Mary Magdalene in Sussex, England. Although the presence of periostitis is not pathognomonic of leprosy, it predominantly indicates dermal and neuropathic changes that the patient would have presented in life. The spread of inflammation across the knee joint and the ossification of the interosseous membrane due to inflammation are also suggested.

Bone and Bones↗
PubMed1994

Inflammatory lesions of ribs: an analysis of the Terry Collection.

The aim of this paper is to consider the diagnostic criteria for tuberculosis in ancient populations. It investigates the frequency of periosteal new bone formation on the visceral surfaces of ribs from 1718 individuals from the Terry Collection, Smithsonian Institution, Washington D.C. and attempts to determine the aetiological factors producing these lesions. Numbers of individuals with lesions according to cause of death were recorded and the patterning of lesions compared between people who had died from tuberculosis and those whose cause of death was unrelated to a pulmonary disease. Rib lesions were more common in individuals dying from tuberculosis (61.6% or 157 of 255) than in individuals dying from other causes (15.2% or 165 of 1086). It is suggested that tuberculosis at a peripheral lung focus may disseminate directly through the pleura to the visceral surfaces of the ribs, or that pulmonary tuberculosis may be the cause of empyema of the pleural cavity and that this, per se, may initiate inflammatory change on the visceral surfaces of ribs. The nonrecognition or description of these often very subtle proliferative lesions on ribs by radiological examination of tuberculous victims is significant in the discussion of bone changes in tuberculosis. The possibility that individuals with no recorded history of tuberculosis at death actually suffered from the disease was considered in light of the frequency of rib lesions and noncorrelation with a tuberculous cause of death. Differential diagnoses are discussed including the possibility that the lesions represent a general non-specific indicator of stress.

Adolescent↗
PubMed1993

Epitopes for natural antibodies of human immunodeficiency virus (HIV)-negative (normal) and HIV-positive sera are coincident with two key functional sequences of HIV Tat protein.

We have previously shown that IgM antibodies that react with human immunodeficiency virus (HIV) Tat, a regulatory protein essential for viral replication, are present in sera of all normal, HIV-negative individuals and deficient in sera of HIV-positive individuals at progressively greater frequency as diagnosis of AIDS nears. That IgM was designated as a set of natural antibodies, a repertoire of the normal humoral immune system believed to provide early defense against infectious invaders. In the prior study, by means of a series of synthetic peptides representing the amino acid sequence of HIV-1 Tat, one epitope for the IgM natural antibodies was defined within the cysteine-rich domain, shown in cell transfection studies to participate in Tat function. In this study we have defined another epitope, within the basic domain, with which the natural antibodies react. The specific sequence and amino acid residues required for that epitope are coincident with those required for the role of Tat in viral replication. The IgM antibodies reactive with the two epitopes of Tat make up two distinct sets, which, together, account for the total Tat reactivity of both HIV-negative and HIV-positive sera. The striking coincidence of the two epitopes with the two functional sequences of Tat suggests a potential role of those natural antibodies in control of HIV pathogenesis. By inference from the extensive evidence for the presence of extracellular Tat in cultures of HIV-infected cells, Tat may be expected to be present in the circulating plasma of infected people. We propose, therefore, that the Tat-reactive natural antibodies, documented in these studies to be present in the circulating plasma in the pre-AIDS stages of HIV infection, may inhibit cell entry of plasma-borne Tat and thereby curtail HIV propagation. Thus, those natural antibodies may be a host factor for delay in HIV pathogenetic progression.

Amino Acid Sequence↗
PubMed1992

Margaret Clitherow: skeletal identification of an historical figure?

This paper describes the use of physical anthropological methods of analysis in attempting to identify an historical figure in England. The historical background to the examination is detailed and reasons for the belief that the skeletal remains excavated from the site were those of a named person, Margaret Clitherow, are discussed. Analysis of age, sex and manner of death indicated that the remains were not those of Margaret Clitherow.

Anthropology, Physical↗