526 results match your criteria: "Imperial College School of Medicine at St. Mary's[Affiliation]"

Hepatitis D virus.

Rev Med Virol

January 1998

Department of Medicine, Division of Medicine, Imperial College School of Medicine at St. Mary's, South Wharf Road, London W2 1NY, UK.

The hepatitis D virus (HDV) relies on the helper hepatitis B virus (HBV) for the provision of its envelope, which consists of hepatitis B surface antigen (HBsAg). The RNA genome of HDV is a circular rod-like structure due to its extensive intramolecular base-pairing. HDV-RNA has ribozyme activity which includes autocatalytic cleavage and self-ligation properties, essential in virus replication via the rolling circle mechanism.

View Article and Find Full Text PDF

The occurrence of new variant Creutzfeldt-Jakob disease and the experimental confirmation that it is caused by the same prion strain as BSE has dramatically highlighted the need for a precise understanding of the molecular basis of prion propagation. The molecular basis of prion-strain diversity, previously a major challenge to the protein-only model, is now becoming clearer. The conformational change thought to be central to prion propagation, from a predominantly alpha-helical fold to one predominantly comprising beta-structure, can now be reproduced in vitro, and the ability of beta-PrP to form fibrillar aggregates provides a plausible molecular mechanism for prion propagation.

View Article and Find Full Text PDF

Objective: To determine the consequences of applying revised American Diabetes Association (ADA) (1997) and World Health Organization (WHO) (1998) recommendations for the classification of glucose intolerance in women with previous gestational diabetes mellitus (GDM).

Research Design And Methods: There were 192 women with previous GDM who took an oral glucose tolerance test (OGTT) 1-86 months after delivery and were classified by WHO (1985), ADA (1997, fasting glucose), and revised WHO (1998) guidelines.

Results: Among the 165 women without a preexisting diagnosis of diabetes, WHO-1985 and ADA-1997 provided similar estimates of diabetes prevalence (13.

View Article and Find Full Text PDF

Social phobia: diagnosis, severity and implications for treatment.

Eur Arch Psychiatry Clin Neurosci

July 1999

Department of Pharmacology, Imperial College School of Medicine at St Mary's, London, UK.

Social phobia has a direct effect on the ability of the individual to interact with others in social or work situations and as a result is associated with a high level of dysfunction. The level of impairment is as severe as that found in other chronic disorders such as depression and is increased by a cascade of comorbidity, which complicates management. Efficacy in social phobia was reported with the MAOIs and this led to the investigation of reversible inhibitors of monoamine oxidase-A (RIMA) which offer a safer alternative.

View Article and Find Full Text PDF

The effect of non-heterosexual factors on the vaginal flora has been studied. Ninety-one lesbians attending a specialist genitourinary medicine service for lesbians were studied. Bacterial vaginosis (BV) was diagnosed in 51.

View Article and Find Full Text PDF

Comparison of immunologic and physiologic effects of CO2 pneumoperitoneum at room and body temperatures.

Surg Endosc

June 1999

Academic Surgical Unit, Imperial College School of Medicine at St. Mary's, Imperial College of Science, Technology and Medicine, Norfolk Place, London, UK.

Background: Prolonged and complex laparoscopic procedures expose patients to large volumes of cool insufflation gas. The aim of this study was to compare the effects of a conventional room temperature carbon dioxide (CO2) pneumoperitoneum with those of a body temperature pneumoperitoneum.

Methods: Patients were randomized to undergo laparoscopic cholecystectomy with a CO2 pneumoperitoneum warmed to either body temperature (n = 15) or room temperature (n = 15).

View Article and Find Full Text PDF

Human type I interferons differ greatly in their effects on the proliferation of primary B cells.

J Interferon Cytokine Res

April 1999

Imperial College School of Medicine at St. Mary's, St. Mary's Hospital, London, UK.

We examined the effects of eight subtypes of human interferon-alpha (IFN-alpha) and human IFN-beta on primary human B cells. In costimulation with antibodies to IgM (but not to CD40), some of these induced the cells to proliferate (but not to differentiate). Individual IFN differed greatly in their relative proliferative effects.

View Article and Find Full Text PDF

A proposed hemopoietic stem cell gene therapy for treatment for HIV infection would involve transduction of CD34+ hemopoietic stem cells with vectors encoding anti-HIV constructs. Peripheral blood has proved to be a useful source of these hemopoietic stem cells and this study exploits this finding. Small quantities of peripheral blood were obtained from HIV-negative patients and HIV-positive patients who were and were not receiving hemopoietic growth factors (HGFs).

View Article and Find Full Text PDF

Progestogen-only contraception is almost invariably associated with changes in menstrual bleeding patterns. Changes in the endometrial vasculature, and in particular an increase in vascular fragility, may contribute to this bleeding. In this study, endometrial vascular density and endothelial cell basement membrane components were examined using immunohistochemistry before and after insertion of Norplant.

View Article and Find Full Text PDF

Human PrP (residues 91-231) expressed in Escherichia coli can adopt several conformations in solution depending on pH, redox conditions and denaturant concentration. Oxidised PrP at neutral pH, with the disulphide bond intact, is a soluble monomer which contains 47% alpha-helix and corresponds to PrPC. Denaturation studies show that this structure has a relatively small, solvent-excluded core and unfolds to an unstructured state in a single, co-operative transition with a DeltaG for folding of -5.

View Article and Find Full Text PDF

Modulation of E2F complexes during G0 to S phase transition in human primary B-lymphocytes.

J Biol Chem

April 1999

Ludwig Institute for Cancer Research and Section of Virology and Cell Biology, Imperial College School of Medicine at St Mary's, London W2 1PG, United Kingdom.

The pocket protein-E2F complexes are convergence points for cell cycle signaling. In the present report, we identified and monitored the pocket protein-E2F complexes in human primary B-lymphocytes after activation by phorbol 12-myristate 13-acetate. Consistent with previous data from human and mouse fibroblasts and T-lymphocytes, E2F4 and DP1 form the predominant E2F heterodimers both in G0 and G1 phases of the human B-lymphocyte cell cycle, whereas E2F1 and -3 are first detected in late G1, and their expression levels increase towards S phase.

View Article and Find Full Text PDF

Background: The reasons why meningococcal disease develops in only a small proportion of individuals carrying the causative bacteria are unknown. Differences in host responses to bacterial colonisation are thought to be involved, since people with deficiencies in the terminal components of the complement pathway, or of properdin, are susceptible to meningococcal disease. We postulate that genetic variants of mannose-binding lectin (MBL), a plasma opsonin that initiates another pathway of complement activation, might similarly cause susceptibility to meningococcal disease.

View Article and Find Full Text PDF

Haemodynamic and hormonal effects of two oral isovolaemic, isoosmotic solutions of 0.5 g/kg and 1.0 g/kg glucose were studied in 10 humans with sympathetic denervation due to primary autonomic failure (AF).

View Article and Find Full Text PDF

Hormone replacement therapy increases isometric muscle strength of adductor pollicis in post-menopausal women.

Clin Sci (Lond)

April 1999

Department of Cellular and Integrative Biology, Division of Biomedical Sciences, Imperial College School of Medicine at St. Mary's, Norfolk Place, London W2 1PG, U.K.

A randomized open trial of hormone replacement therapy was used to assess changes in adductor pollicis muscle strength during 6-12 months of treatment with Prempak C 0.625(R) in comparison with an untreated control group. Muscle strength (maximal voluntary force; MVF), muscle cross-sectional area and bone mineral density were measured.

View Article and Find Full Text PDF

Prion propagation involves the conversion of cellular prion protein (PrPC) into a disease-specific isomer, PrPSc, shifting from a predominantly alpha-helical to beta-sheet structure. Here, conditions were established in which recombinant human PrP could switch between the native alpha conformation, characteristic of PrPC, and a compact, highly soluble, monomeric form rich in beta structure. The soluble beta form (beta-PrP) exhibited partial resistance to proteinase K digestion, characteristic of PrPSc, and was a direct precursor of fibrillar structures closely similar to those isolated from diseased brains.

View Article and Find Full Text PDF

Postural hypotension may result from various neurogenic and non-neurogenic causes. It may be a key feature of certain disorders, such as the primary chronic autonomic failure syndromes; it can complicate a variety of diseases, such as diabetes mellitus; and its prevalence increases with advancing age. When symptomatic, it may result in loss of consciousness and thus cause injury.

View Article and Find Full Text PDF

Chlamydia species in human arthritides.

Rev Rhum Engl Ed

January 1999

Department of Genitourinary Medicine and Communicable Diseases, Imperial College School of Medicine at St Mary's, Paddington, London, UK.

View Article and Find Full Text PDF

Human immunodeficiency virus type 1 (HIV-1) gp120W61D-specific T cell lines (TCL) were generated from an HIV-1-seronegative volunteer who received rgp120W61D in QS21/MPL adjuvant with emulsion. TCL were challenged with pools of consecutive, overlapping peptides spanning the gp120W61D sequence and then with the individual peptides of the immunostimulatory pool. T cell epitopes were found within both variable and conserved domains, and there was no evidence of a single immunodominant epitope.

View Article and Find Full Text PDF

Helicobacter pylori is a gram-negative spiral bacterium confined to the habitat of gastric-type epithelium. H. pylori causes duodenal ulceration by a cumulative effect of antral predominant gastritis with increased acid secretion, consequent gastric metaplasia in the duodenum (a site of further colonization by H.

View Article and Find Full Text PDF

Background: Prion diseases are associated with the accumulation of an abnormal isoform of cellular prion protein (PrPSc), which is the principal constituent of prions. Prions replicate in lymphoreticular tissues before neuroinvasion, suggesting that lymphoreticular biopsy samples may allow early diagnosis by detection of PrPSc. Variant Creutzfeldt-Jakob disease (variant CJD) is difficult to distinguish from common psychiatric disorders in its early stages and definitive diagnosis has relied on neuropathology.

View Article and Find Full Text PDF