Papers by Lawrence Bannister
Plastic and Reconstructive Surgery, 1976
Annals of Tropical Medicine And Parasitology, 1997
Plasmodium falciparum is a eukaryotic single cell which invades human erythrocytes. Within the ho... more Plasmodium falciparum is a eukaryotic single cell which invades human erythrocytes. Within the host cell, the parasite is surrounded by the membrane of the parasitophorous vacuole. Parasite proteins are secreted either into the vacuolar space or are exported, by an as yet unknown mechanism, across the vacuolar membrane into the erythrocyte cytoplasm. In recent years, several groups have devised experimental approaches to follow the transport pathways of proteins from the parasite into the host cell. The concepts underlying these approaches and the peculiarities of the transport pathways are discussed and compared with protein transport in higher eukaryotes.
Journal of Cell Science, 1972
The structure of undischarged and discharged trichocysts has been examined in Paramecium caudatum... more The structure of undischarged and discharged trichocysts has been examined in Paramecium caudatum, and their light-microscopic appearance compared with their fine-structural organization. In living specimens undischarged trichocysts appear to be of a single type with a unimodal variation in length about a mean of 3·7 μm. When fixed for electron microscopy or compressed beneath a coverslip many of the trichocysts expand within the cell, giving rise to a variety of different forms of lower phase density. Ultrastructurally the undischarged trichocyst consists of at least 10 different components: these include a mesh-like sheath surrounding the body of the organelle; an inner and an outer sheath enclosing the tip, the inner sheath being made up of 4 spiralling envelopes with a square net substructure, and the outer sheath being formed of a dense amorphous matrix containing longitudinal microtubules and scattered fine filaments; a boundary surface to the outer sheath; a membranous tricho...
Journal of Cell Science, 1993
Microaggregation of band 3 proteins in hereditary ovalocytic membranes was investigated by rotati... more Microaggregation of band 3 proteins in hereditary ovalocytic membranes was investigated by rotational diffusion measurements and by electron microscopy. It was previously shown that band 3 in ovalocytic membranes has decreased rotational mobility compared with band 3 in normal cells (Tilley, L., Nash, G. B., Jones, G. L. and Sawyer, W. L. (1991) J. Membr. Biol. 121, 59-66). This result could arise from either altered interactions with cytoskeletal proteins or from band 3 microaggregation. In the present study it was found that removal of spectrin and actin from the membrane had no effect on the rotational mobility of ovalocytic band 3. Additional removal of ankyrin and band 4.1, as well as cleavage of the cytoplasmic domain of band 3 with trypsin, did enhance band 3 mobility, as is the case in the membranes from normal cells. However, the rotational mobility of ovalocytic band 3 was always considerably less than that of normal band 3 under the same conditions. Scanning electron micr...
Infection and Immunity, 1992
In malarial infections of primates, the spleen has been shown to modulate parasite antigen expres... more In malarial infections of primates, the spleen has been shown to modulate parasite antigen expression on the surfaces of infected erythrocytes. The processes affected include cytoadherence, which is central to the pathophysiology of severe falciparum malaria, and the related phenomenon of rosette formation. In this study, the cytoadherence and rosette formation behaviors of Plasmodium falciparum-infected erythrocytes from a splenectomized patient were examined during the first erythrocytic cycle in vitro. Ultrastructural studies were also performed. Infected erythrocytes were found to cytoadhere to C32 melanoma cells via leukocyte differentiation antigen CD36 but not intercellular adhesion molecule 1. They also displayed on their surfaces electron-dense knobs similar in structure and density to those on infected erythrocytes from intact hosts. These findings may reflect a stable cytoadherent phenotype of the parasite isolate that is unaffected by the absence of the spleen. Alternati...
Comparative Biochemistry and Physiology, 1968
Crude homogenates of Stentor coeruleus were investigated for the presence of phosphagen kinases. ... more Crude homogenates of Stentor coeruleus were investigated for the presence of phosphagen kinases. Only arginine kinase could be detected. 2. Enzyme activity was tightly associated with the particulate fraction and did not alter significantly between pH 6"5 and 9"5. 3. An ATPase activity also associated with the particulate fraction was slightly enhanced by arginine but depressed by other guanidines. 4. A myosin-like ATPase could not be demonstrated.
Annals of Tropical Medicine & Parasitology, 1995
The biochemical, ultrastructural and experimental data concerning the organization and biological... more The biochemical, ultrastructural and experimental data concerning the organization and biological roles of the merozoite cytoskeleton are briefly reviewed. Actin is known to be expressed in the asexual erythrocytic stages, and has also been demonstrated in Plasmodium falciparum merozoites biochemically and visualized by fluorescence microscopy after appropriate labelling. Experimental evidence indicates that actin-myosinbased motility is important in merozoite locomotion during red-cell invasion. Microtubules also occur in P. falciparum merozoites in the form of a small longitudinal band of subpellicular microtubules, and experiments with anti-microtubule drugs indicate that microtubules are involved in some aspect of invasion. In the late-stage schizont, microtubules are also important in merozoite morphogenesis. The numbers and positions of the merozoite apices within the schizont are spatially related to the spindle poles of the final mitotic division, and extranuclear microtubules are probably responsible for the trafficking of vesicles from a single Golgi cisterna to form the apical organelles. In addition to these cytoskeletal structures, numerous short cytoskeletal filaments of unknown composition attach the merozoite plasma membrane to the underlying pellicular cisterna, and this process may drive the budding of merozoites from the parent schizont.
Nature, 1975
THE mechanism by which molecules interact with, and so stimulate, the surfaces of olfactory recep... more THE mechanism by which molecules interact with, and so stimulate, the surfaces of olfactory receptor cells has given rise to much speculation. Since oil-soluble substances are often very effective odours, it has been proposed that olfactory transduction occurs when an odorant molecule perturbs the lipids of the sensory membranes. Conversely, the known steric aspects of odorant molecule interactions argue for a more specific binding for which a protein would be a more suitable receptor1–4.
Journal of Cell Science
ABSTRACT
Journal of anatomy, 1992
Stimulation with alternating current at the round window causes an accelerated uptake of extracel... more Stimulation with alternating current at the round window causes an accelerated uptake of extracellular HRP by endocytotic vesicles in inner hair cells at the base of the stimulated cochlea, near the site of the electrode, but does not noticeably affect uptake into outer hair cells. After unilateral electrical stimulation, efferent endings on outer hair cells at the cochlear base show increased vesicular and endosomal labelling in both the ipsilateral and contralateral ears. It is concluded that round-window electrical stimulation increases afferent synaptic activity in inner hair cells near the electrode site, and also increases synaptic activity in OHC efferent endings, not only of the ipsilateral cochlea but also of the corresponding region of the contralateral cochlea. Rapid diffuse cytoplasmic labelling of inner and outer hair cells also occurs sporadically in both stimulated and unstimulated cochleae. However, in efferent terminals, diffuse labelling is restricted to stimulated...
The Journal of physiology, 1977
Bulletin of the World Health Organization, 1977
Previous observations on the process of invasion by P. knowlesi are briefly reviewed and new find... more Previous observations on the process of invasion by P. knowlesi are briefly reviewed and new findings concerning the adhesion of parasites to erythrocytes and their intracellular passage are reported. Merozoites adhere to erythrocytes by means of a well-defined coat with the cytochemical characteristics of glycoprotein. This coat has receptors that engage in at least three distinct types of attachment. The ensuing invagination of the erythrocyte surface has two phases, the first consisting of an inward buckling of the membrane to form a vacuole and the second a rapid expansion to create the final parasitophorous vacuole inhabited by the trophic parasite. Some cytochemical evidence concerning the nature of the rhoptry complex is discussed in relation to these changes.
Journal für Hirnforschung, 1973
Blood cells, 1990
Within the circulation, the invasive stage of Plasmodium is the merozoite, a small elliptical cel... more Within the circulation, the invasive stage of Plasmodium is the merozoite, a small elliptical cell. Electron microscopy shows that the merozoite can attach reversibly to erythrocytes by its adhesive coat, then form a close, irreversible contact by its apical end, triggering secretion from membranous vesicles (rhoptries and micronemes) on to the erythrocyte membrane. This causes the erythrocyte membrane to invaginate and the merozoite then becomes enclosed within a cavity lined by interiorized membrane. In uninfected erythrocytes, the surface membrane consists of a lipid bilayer in which lie various integral membrane proteins and glycoproteins, associated at their cytoplasmic ends with a network of other proteins constituting the membrane skeleton. There is much evidence that during invasion the membrane proteins and skeleton are removed from the invaginated membrane. There are also ultrastructural data suggesting that the rhoptries are able to generate membrane-like materials, which...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1975
The Journal of physiology, 1979
Transactions of the St. John's Hospital Dermatological Society, 1975
ABSTRACT
The Journal of Protozoology, 1986
Electron microscopy of schizont development in erythrocytic Plasmodium knowlesi has revealed that... more Electron microscopy of schizont development in erythrocytic Plasmodium knowlesi has revealed that spheroidal vacuoles 250 nm in diameter with semi-dense contents appear at the periphery of the parasite prior to the budding of merozoites. When treated with non-polar solvents, their contents are completely extracted, and after fixation in tannic-glutaraldehyde they contain regular lamellae with a periodicity of 5.5 nm. Both of these reactions are typical of lipids. Some of these structures are associated with phagosomal vacuoles which may contribute to their lamellae. They disappear at the onset of merozoite formation, but membranous whorls of various sizes continue to be associated with the schizont surface during budding of merozoites. It is suggested that the lipidic vacuoles are a source of preformed lipid which can be utilized rapidly during the generation of merozoites.
Nature, 1968
THE structure of the sensory endings of the vomero-nasal organ of vertebrates (Jacobson's or... more THE structure of the sensory endings of the vomero-nasal organ of vertebrates (Jacobson's organ) has been the subject of some controversy in past years1-3. Although the receptor cells seem to resemble closely those of the olfactory epithelium, the presence of cilia on their free ends is arguable. The problem has not yet been investigated by electron microscopy, and it is of interest to report the fine structure of these endings in a reptile, Anguis fragilis, where the vomero-nasal organ is particularly well developed.
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Papers by Lawrence Bannister