Expression of an anti-CD33 single-chain antibody by Pichia pastoris

CD33 is a cell surface glycoprotein expressed on cells of myelomonocytic lineage, leukaemic cells, but not haematopoietic stem cells. By virtue of its expression pattern, CD33 has become a popular target for new immunotherapeutic approaches to treat acute myeloid leukaemia. The methylotrophic yeast Pichia pastoris strain KM71H was used to produce an anti-CD33 single chain variable fragment (scFv), with the intention of conjugation to a radioisotope, for therapeutic use. To direct secreted expression of the anti-CD33-scFv the alpha-mating factor secretory signal sequence (alpha-MF) was used, with constructs containing a complete (CS) and incomplete (INCS) cleavage site to accommodate the potential outcomes of dibasic endopeptidase, Kex2, and dipeptidyl amino peptidase, Ste13, processing. The anti-CD33-scFv was expressed in BMMY cultures using both constructs, with a final yield of 48 mg/l (CS) and 11 mg/l (INCS). N-terminal sequencing showed that the CS-scFv had not been cleaved by Ste13, leaving amino acids EAEA at the N-terminus. The INCS-scFv construct produced a mixture of 50% authentic scFv and 50% with 11 amino acids from the alpha-MF remaining at the N-terminus. Despite the aberrations in alpha-MF processing, the anti-CD33-scFv's produced from both constructs were found to be functional. Flow cytometry and Biacore analysis demonstrated binding to target antigen CD33 on the surface of human leukaemic cell line HL-60, and to recombinant soluble CD33 respectively

Measurements on the growth of gaseous ionization at ultra high frequencies

An apparatus has been built to study ionization by collision in a gas under ultra high frequency fields and especially the conditions covering the transition to the conducting state. The u.h.f. field is developed between two Rogowski profiled electrodes incorporated into a tuned quarter wave transmission line which is loosely coupled to the main oscillator. The u.h.f. field has a frequency of 105 Mc/sec. and its magnitude is measured by its effect on the frequency of oscillation of a small metal disc suspended in the gap. This instrument is used as a step-over so that a rectifying circuit loosely coupled to the transmission line can be calibrated. The disc can be removed from the gap during the experiments. Electrons are emitted from a thermionic cathode situated inside one of the electrodes and diffuse out into the gap through small holes in the electrode shell where they are moved across the gap by a small unidirectional field. The large u.h.f. field is superimposed on this field so that the electrons acquire enough energy to ionize the gas by collision; the resulting electron current to the far electrode is measured by a galvanometer. With this arrangement the amplification resulting from collision ionization can "be measured and its dependence on the lifetime of the electron in the gap can be studied. The measurements can. be carried right up to breakdown conditions, and the results can be expressed in terms of the number of ionizing collisions per second in the life of one electron, a coefficient closely related to Tosnsend's a. It is shown that the lifetime of the electrons not only depends on the drift under the direct field but also on the process of diffusion out of the gap and two methods of evaluating it are given. Although only preliminary results have been obtained these are sufficient to indicate that a useful contribution to ionization studies can be made by investigations with this apparatus

Susceptibility of the upper respiratory tract to influenza virus infection following desialyation

Conference Theme: Translating Health Research into Policy and Practice for Health of the PopulationPoster Presentations - Emerging / Infectious Diseases: no. P132-Ab0100BACKGROUND: Influenza infection begins with the attachment of the viral haemagglutinin (HA) to the surface receptor of a cell. This binding involves a glycan called sialic acid (Sia). Previous studies have suggested that the affinity of influenza viruses isolated from different species depends on the linkage between this Sia and the adjacent sugar (usually galactose). In general, human and swine viruses prefer Sia with an α2-6 linkage while avian viruses prefer an α2-3 linkage. Though there are commercially available therapies that block influenza virus release, there has been limited information on controlling influenza virus infection by …published_or_final_versio

Morphological and molecular characterisation of a mixed Cryptosporidium muris/Cryptosporidium felis infection in a cat

To date Cryptosporidium muris has been identified by microscopy and genotyping in cats in two studies. We report morphological and genetic evidence of a mixed C. muris and C. felis infection in a cat and provide the first histological, immunohistochemical, in situ hybridisation and genetic confirmation of a C. muris infection in the stomach of a cat. The cat suffered persistent diarrhoea after the initial consultation, which remained unresolved, despite several medical interventions. Further studies are required to determine the range, prevalence and clinical impact of Cryptosporidium species infecting cats

WITHDRAWAL OF ENDOGENOUS SYMPATHETIC DRIVE LOWERS BLOOD PRESSURE IN PRIMARY ALDOSTERONISM

We were able to observe the effect of withdrawal of endogenous sympathetic drive in a hypertensive patient with an aldosterone-secreting adrenal adenoma. Acute stimulation of both carotid sinus nerves lowered blood pressure to normotensive or hypotensive levels by reducing peripheral resistance. When chronic carotid sinus nerve stimulation was discontinued, peripheral resistance and blood pressure increased. These data suggest that the sympathetic nervous system is important in the maintenance of hypertension in established primary aldosteronism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73780/1/j.1365-2265.1981.tb00663.x.pd

The diary of Robert John Mullins (1833-1913)

Summary of Content: This volume offers its readers extracts from the diary and the correspondence of Robert John Mullins, Anglican missionary, priest and in due time principal of what was called the Kafir Institution in Grahamstown and as such a pioneer in the field of western education to black South Africans. After his marriage to Jennie Roe he was assisted in all that he undertook by a loyal and devoted wife. The editors have made use of the earlier diaries and manuscripts because of the light they shed on the conditions in the eastern Cape frontier in the crucial years before and after the cattle-killing. While Mullins' own observations are those of a young missionary his remarks and the record of his experiences are themselves to be viewed in the light of the recent scholarship in regard to the cattle-killing which reveals the multisidedness of an appalling social tragedy. What Mullins wrote records, for better or for worse, episodes which show how South Africans of different origins have in the past regarded one another. Mullins was a committed Christian eager to offer to all whom he could reach the salvation of Christ in which he so fervently believed.He was often intolerant of Xhosa customs he could not understand as well as often perplexed and discouraged. But the overwhelming impact of this record is what it took to be a missionary: courage, commitment, humour, resilience, a capacity to endure physical hardship and enjoy physical activity. All these were qualities which Robert John Mullins possessed in abundance. As his diary shows they were the qualities the frontier demanded. Working over a long period of time Nancy Charton and Brenda Nicholls (who became a coeditor in 1991) have transcribed the diary entries and the correspondence working with the help of the sites of some of the missionary activity. The help of members of the Mullins family (notably Judy Sturrock and her husband) is gratefully acknowledged. Earlier generous contributions made it possible to obtain a typescript from which the editors could work. Every effort has been made to identify the individuals (Xhosa, Tembu and white) and events (both in South Africa and abroad) which are alluded to in the diary. This was a time consuming task and the editors are grateful to all who helped them with it. The book consists of an introduction and eleven chapters. The introduction describes the material and the methods of the editors, discusses the religious and social conditions of the time, addresses the problems of interpartition presented by the cattle-killings, turns attention to the dilemmas of missionaries and then focusses the attention of readers on the diarist Robert John Mullins (with Jennie as later stand-in) as well as the value of the diary. There is much to interest the educationist, the theologian, the economist, and the historian. Chapter 1 deals with Mullins' voyage to the Cape in 1854 and the extracts record the experiences of an exuberant as well as a dedicated lad of sixteen. Chapter 2 deals with the arrival at the Cape in 1854. Chapter 3 gives us a picture of Mullins' experience of Graham's Town in 1854. Chapter 4 deals with Mullins' experience at St Luke's Mission. Chapter 5 covers the period of 1856-57 when Mullins was at Balotwa and the cattle-killing frenzy developed. Chapter 6 describes the hunger and turmoil which followed in the wake of the cattle-killing. Chapter 7 describes the founding of a new station, St Peter's Gwytyu. Chapter 8 is concerned with life at St Peter's in the early months of 1858. Chapter 9 covers the last months at St Peter's and his journey to the Bashee. Chapters 10 and 11 cover the early years in the married life of Robert John Mullins and his wife Jennie. The Mullins' delight in family life is strongly evident in their joy in each other's company and their anxious joy over their first-born baby. Chapter 11 gives the reader the texts of letters written by Robert John and his wife Jennie in the years which marked the end of Mullins' career as a frontier missionary, and the opening to him of the opportunity to become Principal of the Kafir Institution. A map carefully prepared by Mr Oakley West of the Geography Department, with the assistance of Deby Brody, enables the reader to trace the frontier journeys of Robert John Mullins and his wife Jennie who were among the pioneers of frontier societies who did their best to make available to others what they believed to be the eternal benefits of the Christian faith, and the accompanying mores of the 'western' culture of their day