bluuebunny/crossref_metadata_2025 huggingface dataset:
Amino acid catabolism in the nematodesHeligmosomoides polygyrusandPanagrellus redivivus2. Metabolism of the carbon skeleton
Authors: Grantham Barbara D. , Barrett J.
Published: June 2009

All of the enzymes of proline catabolism were present inHeligmosomoides polygyrusandPanagrellus redivivusand the activities were, in general, similar to those found in rat liver. Both nematodes were also shown to be able to catabolize the branched-chain amino acids leucine, isoleucine and valine, by pathways similar to those found in mammalian liver. There were no significant differences in amino acid catabolism between the animal-parasitic and free-living species of nematode.
Absence of relationships between selected human factors and natural infectivity of Plasmodium falciparum to mosquitoes in an area of high transmission
Authors: Haji H. , Smith T. , Charlwood J. D. , Meuwissen J. H.
Published: June 2009

The effects of sex, age of the human host, patency of asexual and sexual stages and seasonality on infectiousness of Plasmodium falciparum to mosquitoes were investigated in a rural village in southern Tanzania between 1992 and 1994. Villagers from randomized subgroups of households were surveyed for malaria parasites. Gametocyte and trophozoite prevalences were age dependent and fluctuated without any clear pattern of seasonality. A sample of 107 participants, selected to include an excess of gametocyte carriers, slept under bednets with holes cut into the sides for 3 weeks. A total of 3837 Anopheles gambiae s.l. and 5403 A. funestus recovered from these bednets, was examined for all oocysts 5–7 days after feeding or for oocysts less than 17·5 µn in diameter 2–3 days after feeding. Additional blood slides from participants were taken twice weekly. The 5–7 day oocyst rates were 12·1% in A. gambiae s.l. and 10·9% in A. funestus and 2–3 day rates were 3·6 and 4·9%, respectively. The higher rates using the former method were attributed to previous infection. There were strong correlations in the levels of infection in both vectors when they fed on the same hosts. However, patent gametocytaemia was only weakly associated with the development of oocysts in the mosquito. Infectiousness was not related to host age, sex, or the season.
Matrix metalloproteinases mediate the metastatic phenotype ofTheileria annulata-transformed cells
Authors: Adamson R. E. , Hall F. R.
Published: June 2009

Theileria annulatainfects and reversibly transforms bovine leucocytes. The parasite-transformed cells are immortalized, metastatic and express a number of metalloproteinases including matrix metalloproteinase 9 which they secrete. All the metalloproteinases observed on substrate gels are inhibited by tissue inhibitor of metalloproteinase 1 and 4 synthetic inhibitors BB94, GM6001, BRL29808AI and Ro31–4724. We have adapted anin vitroassay for metastatic behaviour that measures the ability of parasitized cells to cross reconstituted basement membrane, Matrigel™. Using this we demonstrated that macroschizont-infected cells are invasivein vitroand that their invasive properties can be almost eliminated by the same specific inhibitors of metalloproteinases as used in the substrate gels. This demonstrates that the metastatic behaviour of the infected cells is due in part to metalloproteinase activity and strongly suggests a role for the metalloproteinases we observed on gels. This is further supported by the fact that an attenuated vaccine line which shows much reduced metalloproteinase activity also exhibits a marked reduction in metastatic behaviour. We suggest that these metalloproteinases are virulence factors mediating some pathological features of the disease and their loss in the vaccine line could provide an explanation for attenuation.
Expression of NF-Y nuclear factor inSchistosoma mansoni
Authors: Serra E. , Liu J.-L. , Capron A. , Zemzoumi K. , Dissous C.
Published: June 2009

The A subunit of NF-Y nuclear factor fromSchistosoma mansoniwas expressed inE. colifused to a histidine tag and purified by affinity chromatography using a Ni2+-Agarose matrix. Antibodies against the recombinant protein were prepared and used for Western blot and immunolocalization. The presence of SMNF-YA in all stages of the parasite life-cycle was determined by RT-PCR and Western blot analysis. The immunolocalization of SMNF-YA showed the presence of this factor in a parenchymal cell population of cercariae and adult worms and in embryos within eggs. The expression of SMNF-YA was demonstrated to decrease in maturating spermatozoites whereas an accumulation of this factor was observed in the nucleus from oocytes during their maturation processes.
Changes in lipophosphoglycan and gene expression associated with the development ofLeishmania majorinPhlebotomus papatasi
Authors: Saraiva E. M. B. , Pimenta P. F. P. , Brodin T. N. , Rowton E. , Modi G. B. , Sacks D. L.
Published: June 2009

Stage-specific molecular and morphogenic markers were used to follow the kinetics of appearance, number, and position of metacyclic promastigotes developing during the course ofL. majorinfection in a natural vector,Phlebotomus papatasi. Expression of surface lipophosphoglycan (LPG) on transformed promastigotes was delayed until the appearance of nectomonad forms on day 3, and continued to be abundantly expressed by all promastigotes thereafter. An epitope associate with arabinose substitution of LPG side-chain oligosaccharides, identified by its differential expression by metacyclics invitro, was detected on the surface of a low proportion of midgut promastigotes beginning on day 5, and on up to 60% of promatigotes on days 10 and 15. In contrast 100% of the parasites egested from the mouthparts during forced feeding of 15 day infected flies stained strongly for this epitope. At each time-point, the surface expression of the modified LPG was restricted to morphologically distinguished metacyclic forms. Ultrastructural study of the metacyclic surface revealed an approximate 2-fold increase in the thickness of the surface coat compared to nectomonad forms, suggesting elongation of LPG as occurs during metacyclogenesisin vitro. A metacyclic-associated transcript (MAT-1), another marker identified by its differential expression invitro, also showed selective expression by promastigotes in the fly, and was used inin situhybridization studies to demonstrate the positioning of metacyclics in the anterior gut.
Molecular characterization of trypanosome species and subgroups within subgenusNannomonas
Authors: Garside L. H. , Gibson W. C.
Published: June 2009

Restriction fragment length polymorphism (RFLP) analysis of both genomic and kinetoplast DNA from representative stocks from 3Trypanosoma congolensesubgroups (Savannah, Forest, and Kilifi),T. simiaeandT. godfreyi, was used to investigate the relatedness of the different groups within subgenusNannomonas, DNA probes for β-tubulin and the ribosomal DNA (rDNA) locus were isolated from aT. congolenseSavannah genomic library; additional probes were generated by PCR amplification of mini-exon and glutamate and alanine rich protein (GARP) gene sequences. Our results provide evidence that at the molecular level theT. congolenseSavannah and Forest groups are the most closely related groups within the subgenusNannomonas: the Savannah and the Forest groups had mini-exon gene repeats of identical size, which shared homology, had mini-circles of the same size and had a high level of similarity (63%) when the banding patterns produced with a tubulin and rDNA probe were subjected to numerical analysis. All other pairwise combinations of groups have very low percentage similarities of < 10%, suggesting that the Kilifi group trypanosomes, are as distantly related to theT. congolenseSavannah and Forest groups as they are to T.simiaeorT. godfreyi. The conservation of the GARP gene between the Savannah, Forest and Kilifi groups provides the only evidence linking the Kilifi trypanosomes to the other groups inT. congolense. We find no evidence for the presence of the GARP gene in theT. simiaeorT. godfreyigroup trypanosomes.
Identification of a 44 kDa protein localized within the endoplasmic reticulum ofTrypanosoma brucei brucei
Authors: Nandan D. , Wells C. W. , Ndegwa D. , Pearson T. W.
Published: June 2009

Immunoaffinity chromatography and gel electrophoresis were used to isolate a 44 kDa protein that was bound to a 72 kDa chaperone inTrypanosoma brucei brucei. A polyclonal antiserum to the 44 kDa protein was raised in rats and employed in conjunction with chromatography using DEAE-cellulose, Sephacryl S-300, and hydroxyapatite to purify the protein from membranes of bloodstream forms of the trypanosomes. Immunoblot analysis using this antiserum revealed a protein doublet of 44/45 kDa inT. b. bruceiand a single protein band of 53 kDa in almost equivalent amounts throughout the life-cycle stages ofT. congolense. Indirect immunofluorescence using affinity-purified antibodies specific for the 44 kDa protein showed labelling of the perinuclear area and reticular system extending throughout the parasites, suggesting that this protein was located in the endoplasmic reticulum. Localization of the 44 kDa molecule in the endoplasmic reticulum was confirmed by immunoelectron microscopy. Protease protection experiments demonstrated that the epitopes bound by antibody were buried within the membrane or towards the lumenal face of the endoplasmic reticulum. Ruthenium Red overlay of nitrocellulose blots containing the 44/45 kDa doublet suggested that the molecules have the potential to bind calcium. The N-terminal amino acid sequence of the 44 kDa protein showed no sequence similarity to any proteins in the database.
Water contact observations in Kenyan communities endemic for schistosomiasis: methodology and patterns of behaviour
Authors: Fulford A. J. C. , Ouma J. H. , Kariuki H. C. , Thiongo F. W. , Klumpp R. , Kloos H. , Sturrock R. F. , Butterworth A. E.
Published: June 2009

A descriptive analysis of observed water contact activities in seven Kenyan (Akamba) communities is presented. The patterns of contact with time of day, month of year, type of activity, degree of immersion, use of soap, use of ‘kithima’ and day of week are all considered, with particular attention given to how these vary with age and sex. It is noted that (a) patterns of contact vary dramatically between these culturally rather similar communities, (b) contact usually peaks in the second decade of life, (c) generally females, especially young women, spend more time at the water than males and (d) simple (unweighted) total observed duration of contact gives a relatively inflated estimate of exposure in adults, especially young women. The methodology of observation and data handling is described in some detail.
Morphological and histochemical studies on the larval stages of Metastrongylus spp. (lungworms of swine) in the earthworm intermediate host, Eisenia foetida, Savigny 1826
Authors: Probert Allan J.
Published: June 2009

By means of serial sections of experimentally infected Eisenia foetida with Metastrongylus spp. The distribution of larvae within the host has been determined. The exact position in the host intestine at which larvae penetrate has been shown to be the crop. The preferred site for localization and development of the parasite has further been shown to be the lamellar sinuses of the calciferous glands, although larvae were recovered from the dorsal blood vessel, hearts and perienteric blood sinuses. The way in which larvae pass from the gut to their definitive positions in the host has been discussed and it is supposted that this is determined by the configuration of the blood system rather than by a predilection for an environment low in free carbon dioxide. The pathology of infection and the distribution of alkaline and acid phosphatases, lipases, non-specific esterases RNA, DNA and haemaglobin have been described. The distribution of phosphatases in the gut is suggested to be concerned in the uptake of nutrients. The presence of an active zone of enzyme activity in the subcuticular regions of the parasite has been shown and the significance of this discussed. The parasite has been shown to feed directly on host blood.
The evaluation of anthelmintics for the removal of gastro-intestinal nematodes of sheep—an improved form of the controlled test
Authors: Gibson T. E.
Published: June 2009

A modification of the controlled test is described. This is designed to assess the value of a drug against immature as well as against the adult stages of the gastrointestinal nematodes of sheep. The use of faecal egg-count data in the assessment of anthelmintic activity is compared with the critical and controlled tests and the comparative value of all three types of test is discussed.
Studies on the structure of the female reproductive system and egg-shell formation inAspiculuris tetrapteraSchulz, (Nematoda: Oxyuroidea)
Authors: Anya A. O.
Published: June 2009

The histological anatomy of the female reproductive system of an oxyuroid nematode,Aspiculuris tetraptera, Schulz, has been described.

The process of egg-shell formation in this animal has been followed in detail while the structural and chemical characteristics of the egg-shell have been studied by histochemical and other methods. It is shown that there are three layers: a lipoprotein layer, a ‘chitinous’ layer and the so-called vitelline (glycosidal) membrane. Evidence is presented for the exogenous origin of the lipoprotein layer: this being formed by the cells of the upper uterus which are shown to be secretory.

The question of quinone-tanning in the egg-shell ofA. tetrapteraand in other oxyuroids and ascarids is considered. It is shown that neither a polyphenol oxidase nor a high concentration of phenolic substances (apart from protein tyrosine) exists in this system. The significance of these and other observations is discussed in relation to the mechanism of tanning as elucidated in insects and trematodes.

I have to acknowledge with gratitude the support of many during these investigations. To Dr P. Tate for his encouragement and provision of facilities at the Molteno Institute; to Dr D. L. Lee, for much useful discussion and permission to refer to some of his unpublished electron micrographs of nematodes; to Professor J. D. Smyth, who kindly read through the manuscript; to the Cambridge Philosophical Society for a grant that made possible the translation of Fauré-Frémiet's classical study onAscaris;and to the Department of Technical Cooperation for financial assistance.
Immunodepression inGiardia murisandSpironucleus murisinfections in mice
Authors: Brett Sara J.
Published: June 2009

Infections with the intestinal flagellatesGiardia murisandSpironucleus murisare accompanied by a depression in the ability of mice to mount an immune response to a thymus-dependent antigen (sheep red blood cells) but not to a thymus-independent antigen (TNP-lipopolysaccharide). The number of splenic IgM plaque-forming cells and haemagglutination titres, of both IgM and IgG, to sheep red blood cells decreased between days 10 and 21, which correlated with the time of maximal trophozoite levels in the small intestine. The number of background IgM plaque-forming cells to sheep red blood cells or DNP was not significantly different from controls in either infection. No evidence for systemic macrophage activation was associated with these infections. In fact, adherent peritoneal exudate cells (PEC) from infected mice were slightly less cytostatic against target tumour cells than adherent PEC from normal mice, at a time when the parasites were being eliminated from the small intestine.
A comparison of the effects of flubendazole and thiabendazole on the larvae of Angiostrongylus cantonensis, Trichinella spiralis, Diphyllobothrium erinacei and Hymenolepis nana in mice
Authors: Maki Jun , Yanagisawa Toshio
Published: June 2009

Flubendazole or thiabendazole were administered orally to mice harbouring larvae of Angiostrongylus cantonensis, Trichinella spiralis, Diphyllobothrium erinacei or Hymenolepis nana 5–10, 28–33 and 21–26 and 1–6 days post-infection respectively. All the mice infected with A. cantonensis were completely cured after treatment with flubendazole at 5 mg/kg/day for 6 days. No noticeable damage was found in the cerebral hemispheres of the mice treated with flubendazole and examined under a dissecting microscope. On the other hand, larvae were found in or on the cerebral hemispheres showing obvious haemorrhage in the control mice. The mice treated with flubendazole gained weight while the control mice lost weight. No larvicidal effect of thiabendazole on A. cantonensis was found at a dose of 10 mg/kg/day for 6 days. The mean reduction of larval T. spiralis in mice treated with flubendazole at 5, 50 and 100 mg/kg/day for 6 days was 64, 100 and 99% respectively. In comparison, thiabendazole showed no efficacy against T. spiralis larvae at 50 or 100 mg/kg/day. Mice harbouring plerocercoids of D. erinacei or H. nana larvae were not cured with either flubendazole or thiabendazole at 50 or 100 mg/kg/day for 6 days.
Implications of genetic exchange in the study of protozoan infections
Authors: Walliker D.
Published: June 2009

Genetic exchange is now known to occur during the life-cycle of many parasitic protozoa, including malaria parasites, coccidia and trypanosomes. The process is studied by making deliberate crosses between cloned organisms differing in clearly defined markers. In malaria parasites, crosses have been made between parasites differing in characters such as isoenzymes, antigens and other proteins, drug sensitivity, and chromosome and other DNA polymorphisms. Crosses are made by transmitting a mixture of gametes of each clone through mosquitoes to allow cross-fertilization to take place, and examining the resulting progeny by cloning for organisms exhibiting non-parental combinations of characters. The inheritance of many characters, such as antigen and protein variants, is in accordance with Mendelian expectations for a haploid organism. Recombination occurs at a higher than expected frequency. Studies on chromosomes have show that crossing-over events commonly occur following meiosis of hybrid zygotes. Repetitive DNA and subtelomeric regions of chromosomes appear to be particularly susceptible to such recombination events. In trypanosomes, crosses between clones ofTrypanosoma bruceihave shown that hybrids are formed during tsetse fly transmission. The organism appears to be mainly diploid, but some characters including certain chromosomes seem to be inherited in a non-Mendelian manner.
From the bench to the field: control of parasitic infections within primary health care
Authors: Tanner M.
Published: June 2009

During the last decade there has been a great increase in the number of countries that have endorsed the primary health care (PHC) policy at national level, set up national guidelines for it and launched its large-scale implementation. In addition, there have been many important developments with regard to appropriate, cost-effective technologies, training concepts and approaches to securing community participation. These achievements have produced numerous encouraging results. However, although the control of parasitic infections integrated into PHC systems has often been initially successful, these achievements could often not be sustained. Using case studies, mainly concerning schistosomiasis, as examples, control technologies and their applicability within PHC are discussed at three levels; the identification of public health priorities, the community-based implementation of control and the process of evaluation and monitoring. There is a great potential for the integration of a substantial part of control activities, particularly morbidity control, into PHC, provided that the aims and sequences of control activities are well matched with the felt needs of the communities concerned. This implies that the biomedical researcher, the epidemiologist and the health planner need to consider the indigenous health perspectives of the affected community. For example, recent progress in the laboratory in the development of vaccines against parasites needs to be complemented by field studies that continuously validate, standardize and assess the applicability of the proposed measures. This kind of interplay will form the basis for participatory approaches in health planning and make it possible for control activities to be integrated into existing PHC structures and to respond to the needs of the communities concerned.
Some new Myxosporidia from Plymouth with a proposed new classification of the Order
Authors: Tripathi Yogendra R.
Published: June 2009

Four new species of myxosporidian parasites are described from marine fishes from Plymouth:Sinuolinea rebaen.sp., from the urinary bladder ofSolea solea; Leptotheca vikramin.sp., from the gall bladder ofZeus faber; Zschokkella russellin.sp., from the gall bladder ofGaidropsarus tricirratusandCiliata mustela; andZschokkella sturionisn.sp., from the gall bladder ofAcipenser sturio.

The various terms used in describing the spore of Myxosporidia are reviewed and revised.

A new classification is proposed of the order Myxosporidia.

I wish to thank the Director of the Marine Biological Association's Laboratory for all the facilities he has enabled me to enjoy during my stay at Plymouth, by dedicating a new species ofZschokkellato him. As a mark of gratitude, and with a deep sense of respect to His Highness the Maharaja of Narsinghgarh State, C.I., I take the liberty of dedicating to him the new species ofLeptothecaI have discovered. But for his encouragement and help in the early stages of my career it would have been impossible for me to apply for the India State Scholarship which I now hold. I take this opportunity of expressing my thanks to Miss N. G. Sproston for her unfailing help and encouragement during the present studies and am very grateful to her for going through the manuscript critically.
Studies on some parasites of fishes
Authors: Weiser Jaroslav
Published: June 2009

The material described in the present paper was collected by Dr Rašín in 1935. It consisted of an infected ovary of Leuciscus cephalus L. from the Svitava river near Brno, and an ovary of Esox lucius from Ríčka in the vicinity of Vranovice near Brno, C.S.R. The ovaries were fixed partly with formol-Zenker solution, and partly with Gilson's fixative. The infected roes could be distinguished easily from the healthy ones by their white colour. Histological examination showed that they were infected with Microsporidia. As the material had been fixed, no polar filaments could be observed. Sections, 4μ in thickness, were stained with Heidenhain's iron haematoxylin, which once more proved to be a stain which gave the greatest contrast in preparations of Microsporidia. In addition, sections were stained with Mallory and Mann's stains, and were also subjected to Feulgen's nucleal reaction.
The differentiation and nomenclature of Leishmania
Authors: Kirk R.
Published: June 2009

1. The nomenclature and synonymy of the Leishmania of man and of the dog is reviewed.

2. Many of the older names have been discarded and medical writers now recognize only two, or at the most three, species of Leishmania of man and dogs.

3. These species are indistinguishable morphologically. Attempts to differentiate them by the techniques of bacteriology have given conflicting results and there is no general agreement that they can be so differentiated.

4. It has been suggested that separation of species of Leishmania is not justified under the present rules of systematics and that all forms of human and canine leishmaniasis must be regarded as the result of infection by a single species of parasite.

5. This suggestion is not entirely acceptable in view of contributions to the subject by medical workers who have studied the results of infection in the human subject intensively and continuously for half a century.

6. Evidence is produced that the different types of human leishmaniasis recognized clinically can be correlated with biological differences in the causal parasites.

7. In other organisms which have been intensively studied the existence of groups which differ from each other in biological characters only is widely recognized in modern systematics, but there is no general agreement about nomenclature for the definition of such groups.

8. Reasons, not inconsistent with modern studies in systematics, are given for the recognition of at least three groups in the Leishmania of man, corresponding with the L. donovani, L. tropica and L. brasiliensis of medical text-books. Definition of the taxonomic status of such groups will depend on the further progress of systematics.
The distribution of cimicidae (Hemiptera) in the Anglo-Egyptian Sudan
Authors: Lewis D. J.
Published: June 2009

1. The distribution of Cimex hemipterus and C. lectularius in the Sudan is described. Leptocimex boueti has been found in two localities.

2. Reasons for the distribution of the two species of bed-bug are discussed, and it is considered likely that facilities for dispersal and atmospheric humidity may have been the most important factors.
Description of a plasmodium found in a bat, Roussettus leachi
Authors: Riel J. Van , D.  , Hiernaux-L'Hoëst J.
Published: June 2009

The intra-erythrocytic development of a parasite of the frugivorous bat, Roussettus leachi, has been, observed. The name Plasmodium roussetti has been suggested temporarily. The rosettes are typical of the genus Plasmodium. The parasites can be transmitted congenitally and gametocytes have been found in foetal blood.

This work has been made possible by grants from the Fonds National de la Recherche Scientifique and from the Institut pour la Recherche Scientifique en Afrique Centrale.
Two new mite parasites of Natal bats (Listrophoridae, Sarcoptiformes)
Authors: Lawrence R. F.
Published: June 2009

Three species of Listrophorid mites representing two genera, Alabidocarpus and Labidocarpus, are known from the European horse-shoe bat Rhinolophus ferroequinum, and one species of Alabidocarpus, A. nasicolus, has already been described (1938) from the closely related Natal horseshoe bat Rhinolophus geoffroyi zuluensis.
On the morphology and life history of a new mammalian blood-fluke—Ornithobilharzia dattai n.sp. (Preliminary report).
Authors: Dutt S. C. , Srivastava H. D.
Published: June 2009

Of the fifteen valid species of mammalian blood-flukes so far known, six have been originally described from India. Montgomery (1906) described Schistosoma indicum, S. spindalis and Ornithobilharzia bomfordi (Montgomery, 1906) Price, 1929. Datta (1932) found that nasal granuloma of cattle is due to a new schistosome, which was subsequently obtained and described as Schistosoma nasalis by Rao (1933). Rao & Ayyar (1933) obtained a new schistosome from pigs and described it as S. suis. Mudaliar & Ramanujachari (1945) described S. nairi n.sp., from an elephant, which was transferred to the genus Ornithobilharzia by Bhalerao (1947). Another new species of blood-fluke has now been found in Indian buffaloes and cattle. While studying the larval trematode fauna of the local aquatic snails, large numbers of a new schistosome cercaria were obtained from nine out of three hundred specimens of Limnaea luteola examined during November 1950. When the cercariae were administered to two guinea-pigs, a buffalo-calf and a bull-calf, they developed into an interesting blood-fluke referable to the genus Ornithobilharzia Odhner, 1912. Subsequently, three out of thirteen buffaloes examined post-mortem were found to be naturally infected with the same parasite. The morphology of the adult and of its cercaria is briefly described in this paper.
Extracellular matrix in plasticity and epileptogenesis
Authors: Dityatev Alexander , Fellin Tommaso
Published: June 2009

Extracellular matrix (ECM) in the brain is composed of molecules synthesized and secreted by neurons and glial cells in a cell-type-specific and activity-dependent manner. During development, ECM plays crucial roles in proliferation, migration and differentiation of neural cells. In the mature brain, ECM undergoes a slow turnover and supports multiple physiological processes, while restraining structural plasticity. In the first part of this review, we discuss the contribution of ECM molecules to different forms of plasticity, including developmental plasticity in the cortex, long-term potentiation and depression in the hippocampus, homeostatic scaling of synaptic transmission and metaplasticity. In the second part, we focus on pathological changes associated with epileptogenic mutations in ECM-related molecules or caused by seizure-induced remodeling of ECM. The available data suggest that ECM components regulating physiological plasticity are also engaged in different aspects of epileptogenesis, such as dysregulation of excitatory and inhibitory neurotransmission, sprouting of mossy fibers, granule cell dispersion and gliosis. At the end, we discuss combinatorial approaches that might be used to counteract seizure-induced dysregulation of both ECM molecules and extracellular proteases. By restraining ECM modification and preserving thestatus quoin the brain, these treatments might prove to be valid therapeutic interventions to antagonize the progression of epileptogenesis.
Tumour‐experienced T cells promote NK cell activity through trogocytosis of NKG2D and NKp46 ligands
Authors: Domaica Carolina I , Fuertes Mercedes B , Rossi Lucas E , Girart María V , Ávila Damián E , Rabinovich Gabriel A , Zwirner Norberto W
Published: June 2009

Natural killer (NK) cells trigger cytotoxicity and interferon (IFN)‐γ secretion on engagement of the natural‐killer group (NKG)2D receptor or members of the natural cytotoxicity receptor (NCR) family, such as NKp46, by ligands expressed on tumour cells. However, it remains unknown whether T cells can regulate NK cell‐mediated anti‐tumour responses. Here, we investigated the early events occurring during T cell–tumour cell interactions, and their impact on NK cell functions. We observed that on co‐culture with some melanomas, activated CD4+ T cells promoted degranulation, and NKG2D‐ and NKp46‐dependent IFN‐γ secretion by NK cells, probably owing to the capture of NKG2D and NKp46 ligands from the tumour‐cell surface (trogocytosis). This effect was observed in CD4+, CD8+ and resting T cells, which showed substantial amounts of cell surface major histocompatibility complex class I chain‐related protein A on co‐culture with tumour cells. Our findings identify a new, so far, unrecognized mechanism by which effector T cells support NK cell function through the capture of specific tumour ligands with profound implications at the crossroad of innate and adaptive immunity.
RNAP subunits F/E (RPB4/7) are stably associated with archaeal RNA polymerase: using fluorescence anisotropy to monitor RNAP assembly in vitro
Authors: Grohmann Dina , Hirtreiter Angela , Werner Finn
Published: June 2009

Archaeal and eukaryotic RNAPs (DNA-dependent RNA polymerases) are complex multi-subunit enzymes. Two of the subunits, F and E, which together form the F/E complex, have been hypothesized to associate with RNAP in a reversible manner during the transcription cycle. We have characterized the molecular interactions between the F/E complex and the RNAP core. F/E binds to RNAP with submicromolar affinity and is not in a dynamic exchange with unbound F/E.
Tobacco control practices among Aboriginal health professionals in Western Australia
Authors: Pilkington Albert (Sonny) A. G. , Carter Owen B. J. , Cameron Alexander S. , Thompson Sandra C.
Published: June 2009

Smoking among Aboriginal people is extremely widespread (50 v. 17% of the general population). Aboriginal Health Workers (AHW) are at the vanguard of tackling this problem but many themselves smoke and little is known of their knowledge, attitudes and practices regarding smoking cessation. Structured telephone interviews were conducted with 36 AHW, including 31% current smokers, 31% ex-smokers and 38% non-smokers, to assess their current smoking cessation practices and knowledge of health risks, nicotine dependence, cessation strategies and pharmacotherapies. AHW considered diabetes, alcohol use and heart disease more problematic than smoking among Aboriginal people. Fear of appearing hypocritical stopped many who smoke from discussing smoking cessation with clients but also stopped some non-smoking AHW whose colleagues or family smoked. Cultural concerns about telling others ‘what to do’ was also a major impediment. Knowledge of the health effects of smoking was good, but knowledge of appropriate advice around cessation pharmacotherapies was suboptimal. AHW trained in smoking cessation were more knowledgeable and active in smoking cessation, but most AHW had received no training, despite being keen to do so. Specific smoking cessation training is sought and appears needed by AHW, particularly in the areas of brief interventions, motivational interviewing, dependence assessment and pharmacotherapies.
Seeing the forest for the trees: using the Gene Ontology to restructure hierarchical clustering
Authors: Dotan-Cohen Dikla , Kasif Simon , Melkman Avraham A.
Published: June 2009

Motivation: There is a growing interest in improving the cluster analysis of expression data by incorporating into it prior knowledge, such as the Gene Ontology (GO) annotations of genes, in order to improve the biological relevance of the clusters that are subjected to subsequent scrutiny. The structure of the GO is another source of background knowledge that can be exploited through the use of semantic similarity.

Results: We propose here a novel algorithm that integrates semantic similarities (derived from the ontology structure) into the procedure of deriving clusters from the dendrogram constructed during expression-based hierarchical clustering. Our approach can handle the multiple annotations, from different levels of the GO hierarchy, which most genes have. Moreover, it treats annotated and unannotated genes in a uniform manner. Consequently, the clusters obtained by our algorithm are characterized by significantly enriched annotations. In both cross-validation tests and when using an external index such as protein–protein interactions, our algorithm performs better than previous approaches. When applied to human cancer expression data, our algorithm identifies, among others, clusters of genes related to immune response and glucose metabolism. These clusters are also supported by protein–protein interaction data.

Contact:  dotna@cs.bgu.ac.il

Supplementary information:  Supplementary data are available at Bioinformatics online.
UTGB toolkit for personalized genome browsers
Authors: Saito Taro L. , Yoshimura Jun , Sasaki Shin , Ahsan Budrul , Sasaki Atsushi , Kuroshu Reginaldo , Morishita Shinichi
Published: June 2009

The advent of high-throughput DNA sequencers has increased the pace of collecting enormous amounts of genomic information, yielding billions of nucleotides on a weekly basis. This advance represents an improvement of two orders of magnitude over traditional Sanger sequencers in terms of the number of nucleotides per unit time, allowing even small groups of researchers to obtain huge volumes of genomic data over fairly short period. Consequently, a pressing need exists for the development of personalized genome browsers for analyzing these immense amounts of locally stored data. The UTGB (University of Tokyo Genome Browser) Toolkit is designed to meet three major requirements for personalization of genome browsers: easy installation of the system with minimum efforts, browsing locally stored data and rapid interactive design of web interfaces tailored to individual needs. The UTGB Toolkit is licensed under an open source license.

Availability: The software is freely available at http://utgenome.org/.

Contact:  moris@cb.k.u-tokyo.ac.jp
Nutritional regulation of differentiation and synthesis of an exocytoplasmic deoxyriboendonuclease in Streptomyces antibioticus
Authors: De los Reyes-Gavilán Clara G. , Cal Santiago , Barbés Covadonga , Hardisson Carlos , Sánchez Jesus
Published: June 2009

Streptomyces antibioticus produces a cell-wall-located deoxyriboendonuclease (DNAase) the synthesis of which in submerged and surface cultures is related to the growth rate. DNAase synthesis always preceded aerial mycelium formation in surface cultures. Production of aerial mycelium began at the end of exponential growth or in the early stationary phase; it was absent in cultures grown on nutrient agar/glucose or in media with a high concentration of casein hydrolysate. These nutritional conditions also impaired production of the DNAase. External DNA substrates were not degraded by mycelium producing the DNAase. These observations lead us to suggest a role for the enzyme in the developmental cycle of S. antibioticus.
Two classes of ethidium-bromide-resistant mutants of Streptomyces lividans 66
Authors: Lee Li-Fong , Huang Yi-Jiun , Chen Carton W.
Published: June 2009

Five spontaneous mutants of Streptomyces lividans TK64 resistant to 5 or 15 μM ethidium bromide (EB) were isolated, and the corresponding mutations were mapped to two different chromosomal locations. Both types of mutations conferred unselected resistance to several basic dyes and norfloxacin. The strain with the low-level resistance exhibited wild-type levels of EB uptake and energy-dependent efflux, and the resistance mechanism is unclear. The highly resistant mutants, which additionally were resistant to phosphonium ions, had a reduced accumulation and an increased efflux of EB, reminiscent of a mammalian multidrug resistance efflux pump.
Surface location of HPr, a phosphocarrier of the phosphoenolpyruvate: sugar phosphotransferase system in Streptococcus suis
Authors: Dubreuil J. D. , Jacques M. , Brochu D. , Frenette M. , Vadeboncoeur C.
Published: June 2009

HPr is a low-molecular-mass phosphocarrier protein of the bacterial phosphoenolpyruvate (PEP): sugar phosphotransferase system (PTS) found in the cytoplasm or associated with the inner surface of the cytoplasmic membrane. Treatment of Streptococcus suis cells with a Sorvall Omnimixer, a technique used to extract cell surface components, resulted in the extraction of a major protein with a molecular mass of 9 kDa. Several lines of evidence suggested that this protein was HPr: (i) the S. suis protein showed homology over the first 35 N-terminal amino acid residues with the HPrs of Streptococcus salivarius and Streptococcus mutans, including the signature sequence for the site of PEP-dependent phosphorylation; (ii) it cross-reacted with the S. salivarius anti-HPr antibody preparation; (iii) it could be phosphorylated by enzyme 1 at the expense of PEP, and by a membrane-associated kinase at the expense of ATP; and (iv) it possessed phosphocarrier activity when used as a source of HPr in an in vitro PTS assay. The data suggested that a portion of the cellular HPr is associated with the external cell surface in S. suis, a result that was confirmed by immunogold electron microscopy. The cellular HPr of S. suis consisted of two forms that could be distinguished by the presence or the absence of the N-terminal methionine. Amino acid sequence analysis indicated that the cell-surface-associated HPr of S. suis lacked the N-terminal methionine residue.
Stress resistance and recovery potential of culturable and viable but nonculturable cells of Vibrio vulnificus
Authors: Weichart Dieter , Kjelleberg Staffan
Published: June 2009

The estuarine, human-pathogenic bacterium Vibrio vulnificus responds to low temperature by the formation of viable but nonculturable (VBNC) cells, while starvation at moderate temperatures allows for maintenance of culturability of this organism. Recovery of cold-incubated populations of V. vulnificus was restricted to the culturable fraction in slide cultures and most probable number assays. These populations, however, gave between 1.1- and 8-fold higher c.f.u. counts on soft agar plates than on ordinary agar plates, indicating that a small and variable fraction of the cell population was injured rather than nonculturable. Thus, the population of cold-incubated cells is composed of culturable, injured and nonculturable cells, with the numbers of the culturable and injured cells rapidly decreasing during cold incubation. Recovery of nonculturable cells of the organism, however, could not be obtained by any combination of temperature and nutrient shifts in any of the assays. VBNC cells of the organism were assessed with regard to their persistence and stress resistance in comparison to growing and starved cells. The sonication resistance of VBNC cells was initially similar to that of growing cells, but increased during prolonged cold incubation. The final resistance of cold-incubated VBNC cells was equal to the markedly increased resistance of starving cells, which also displayed increased resistance against exposure to ethanol and mechanical stress. Our results indicate that in spite of the apparent absence of recovery under a wide range of laboratory conditions, VBNC cells of V. vulnificus undergo changes at low temperature which potentially allow them to persist for extended periods.
Organization of ribosomal RNA genes from the footrot pathogen Dichelobacter nodosus
Authors: La Fontaine Sharon , Rood Julian I.
Published: June 2009

Southern hybridization analysis revealed that there were three rrn loci within the genome of Dichelobacter nodosus, the causative organism of ovine footrot. These loci (rrnA, rrnB and rrnC) were isolated on recombinant lambda clones, and comprised 16S, 23S and 5S rRNA genes closely linked in that order. Sequence and primer extension analysis revealed the presence of putative genes encoding tRNAlle and tRNAAla within the 16S-23S spacer region, as well as a number of potential regulatory features. These elements included a single promoter, which was mapped upstream of the 16S rRNA gene and which was similar to
Escherichia coli
consensus promoter sequences, an AT-rich upstream region, a GC-rich motif that may be involved in stringent control, leader and spacer antitermination sequences, sites for ribonuclease processing, and a putative factor-independent terminator sequence. Potential open reading frames (ORFs) were identified within the regions flanking the rrn loci, with identical copies of the 3′ terminal ORF present downstream of each rRNA operon. Determination of the complete sequence of the 5S rRNA gene, and derivation of the 5S rRNA secondary structure, further substantiated the 16S rRNA-based placement of D. nodosus within the gamma division of the Proteobacteria.
bofC Encodes a Putative Forespore Regulator of the Bacillus Subtilis σk Checkpoint
Authors: Gomez Manuel , Cutting Simon M.
Published: June 2009

A mutation, bofC1, that restores σK activation in Bacillus subtilis strains unable to produce active σG has been identified. This mutation defines a new sporulation gene, bofC, that has been cloned and sequenced and encodes a 19 kDa protein. bofC is transcribed in the forespore by RNA polymerase associated with the transcription factors σF (EσF) and σG (EσG). BofC acts negatively on SpolVB and the results described suggest that BofC regulates SpolVB activity and its intercompartmental signalling role in the σK checkpoint
Expression and Content of Terminal Oxidases in Azotobacter Vinelandii Grown with Excess NH4+ are Modulated by O2 Supply
Authors: D'mello Rita , Purchase Diane , Poole Robert K. , Hill Susan
Published: June 2009

The influence of the rate of O2 supply to batch cultures on the contents of cytochromes bd and ‘o’ in NH4
+-grown Azotobacter vinelandii has been investigated. Difference spectra at room temperature (reduced + CO minus reduced) were recorded for whole cells of a wild-type strain and mutants which either lacked or over-produced the cytochrome bd-type terminal oxidase encoded by cydAB. A Tn5-B20 insertion in cydB in the former mutant also provided a means of monitoring cydAB gene expression from measurements of β-galactosidase activity. The content of cytochrome d in the wild-type, and the expression of cydAB-lacZ, in the mutant, increased as the O2 supply was raised, suggesting that O2 regulates cydAB expression even in the absence of diazotrophy. In a strain carrying a mutation in cydR, a regulatory gene upstream of cydAB, and which over-produces cytochrome bd, the responses to O2 supply during growth at different O2 supply rates were reversed. Changes in the content of a haemoprotein detectable in low temperature photodissociation spectra, and attributed to cytochrome b
595 -the high-spin cytochrome b component of the cytochrome bd complex - followed the changes in cytochrome d levels. CO difference spectra of both the wild-type strain and the cytochrome bd-deficient mutant revealed a haemoprotein with spectral characteristics similar to cytochrome o, the levels of which increased as the O2 supply was raised. These results are discussed with reference to previous reports of cytochrome changes in cells grown under N2-fixing conditions.
Disruption of the Pseudomonas aeruginosa dipZ gene, encoding a putative protein-disulfide reductase, leads to partial pleiotropic deficiency in c-type cytochrome biogenesis
Authors: Page M. Dudley , Saunders Neil F. W. , Ferguson Stuart J.
Published: June 2009

The Pseudomonas aeruginosa dipZ gene has been cloned and sequenced. Whereas disruption of Escherichia coli dipZ (dsbD), the hydrophilic C-terminal domain of which has been deduced to be periplasmic and to function as a protein-disuifide reductase, leads to the absence of c-type cytochromes, disruption of P. aeruginosa dipZ attenuated, but did not abolish, holo-c-type cytochrome biosynthesis. Comparison of the P. aeruginosa DipZ sequence with three other DipZ sequences indicated that there are not only two conserved cysteine residues in the C-terminal hydrophilic domain, but also two more in the central highly hydrophobic domain. The latter would be located toward the centre of two of the eight membrane-spanning α-helices predicted to compose the hydrophobic central domain of DipZ. Both these cysteine residues, plus other transmembrane helix residues, notably prolines and glycines, are also conserved in a group of membrane proteins, related to Bacillus subtilis CcdA, which lack the N- and C-terminal hydrophilic domains of the DipZ proteins. It is proposed that DipZ of P. aeruginosa and other organisms transfers reducing power from the cytoplasm to the periplasm through reduction and reoxidation of an intramembrane disulfide bond, or other mechanism involving these cysteine residues, and that this function can also be performed by B. subtilis CcdA and other CcdA-like proteins. The failure of dipZ disruption to abolish c-type cytochrome synthesis in P. aeruginosa suggests that, in contrast to the situation in E. coli, the absence of DipZ can be compensated for by one or more other proteins, for example a CcdA-like protein acting in tandem with one or more thioredoxin-like proteins.