bluuebunny/crossref_metadata_2025 huggingface dataset:
Osteoporosis in Pediatric Patients Suffering From Chronic Inflammatory Bowel Disease With and Without Steroid Treatment
Authors: Walther Frank , Fusch Christoph , Radke Michael , Beckert Sybille , Findeisen Annette
Published: July 2006

Background:

Children and adolescents suffering from inflammatory bowel disease (IBD) are at risk of developing osteoporosis as a result of treatment with corticosteroids as well as of nonsteroidal factors like inflammation and malnutrition. To study the impact of these factors on development of osteopathy, we compared the rate of osteoporosis in steroid‐naive and steroid‐treated pediatric IBD patients.

Methods:

In 90 patients (50 girls) with IBD (34 steroid‐naive, 53 steroid‐treated, 3 not known) aged 8.8 to 19.2 (14.4 ± 2.2) years and 52 controls (27 girls) aged 6.1 to 17.6 (12.9 ± 3.0) years, bone mineral density (BMD) of the lumbar spine was assessed with dual energy x‐ray absorptiometry. Areal BMD values were transformed into volumetric densities called bone mineral apparent density (BMAD) and expressed as standard deviation scores (SDS) on the basis of the BMAD values of the controls.

Results:

The rate of osteoporotic patients (BMAD‐SDS < −2) was 8% in girls and 20% in boys. There was a similar proportion of osteoporosis in steroid‐naive (12%) and steroid‐treated (11%) patients. SDS of body height showed a significant positive correlation with BMD‐SDS but not with BMAD‐SDS in almost all patient subgroups, indicating an interfering dependency of BMD from bone size.

Conclusions:

The prevalence of osteoporosis in pediatric patients with IBD is approximately the same as in adult patients. Osteoporosis is already present before steroid treatment. Data of dual energy x‐ray absorptiometry measurements should be transformed into volumetric parameters to compensate for short stature. Otherwise, a lot of growth‐stunted patients may be falsely diagnosed as osteopenic.
An MMP liberates the Ninjurin A ectodomain to signal a lossof cell adhesion
Authors: Zhang Shuning , Dailey Gina M. , Kwan Elaine , Glasheen Bernadette M. , Sroga Gyna E. , Page-McCaw Andrea
Published: July 2006

Matrix metalloproteinases (MMPs) are important for developmental tissue remodeling and for the inflammatory response. Although the vertebrate MMP family is large and functionally redundant, the fruitfly Drosophila melanogaster has only two MMPs, both essential genes. Our previous work demonstrated that Mmp1 is required for growth of the tracheal system, and we suggested that the mutant phenotype resulted from aberrant persistence of cell adhesion to the extracellular matrix. Here we report the identification of NijA, a transmembrane protein whose vertebrate homologs regulate cell adhesion, as a two-hybrid binding partner for Mmp1. The binding of Mmp1 and NijA was confirmed by coimmunoprecipitation of endogenous proteins from flies, and the endogenous proteins were found to colocalize at the tracheal cell surface in larvae. When NijA is expressed in S2 cells, they lose adhesion to surfaces; this adhesion-loss phenotype is dependent on the expression and catalytic activity of Mmp1. Our data indicate that Mmp1 releases the N-terminal extracellular domain of NijA. This liberated ectodomain promotes the loss of cell adhesion in a cell-nonautonomous manner. We suggest that tracheal cell adhesion is regulated by a novel mechanism utilizing an MMP and a ninjurin family member.
Evidence for a novel protease governing regulated intramembrane proteolysis and resistance to antimicrobial peptides in Bacillus subtilis
Authors: Ellermeier Craig D. , Losick Richard
Published: July 2006

Evidence is presented that the activation of the RNA polymerase σ factor σW in Bacillus subtilis by regulated intramembrane proteolysis is governed by a novel, membrane-embedded protease. The σW factor is activated by proteolytic destruction of the membrane-bound anti-σW factor RsiW in response to antimicrobial peptides and other agents that damage the cell envelope. RsiW is destroyed by successive proteolytic events known as Site-1 and Site-2 cleavage. Site-2 cleavage is mediated by a member of the SpoIVFB-S2P family of intramembrane-acting metalloproteases, but the protease responsible for Site-1 cleavage was unknown. We have identified a previously uncharacterized, multipass membrane protein called PrsW (annotated YpdC) that is both necessary and sufficient (when artificially produced in an unrelated host bacterium) for Site-1 cleavage of RsiW. PrsW is a member of a widespread family of membrane proteins that includes at least one previously known protease. We identify residues important for proteolysis and a cluster of acidic residues involved in sensing antimicrobial peptides and cell envelope stress.
Drosophila ribosomal proteins are associated with linker histone H1 and suppress gene transcription
Authors: Ni Jian-Quan , Liu Lu-Ping , Hess Daniel , Rietdorf Jens , Sun Fang-Lin
Published: July 2006

The dynamics and function of ribosomal proteins in the cell nucleus remain enigmatic. Here we provide evidence that specific components of Drosophila melanogaster ribosomes copurify with linker histone H1. Using various experimental approaches, we demonstrate that this association of nuclear ribosomal proteins with histone H1 is specific, and that colocalization occurs on condensed chromatin in vivo. Chromatin immunoprecipitation analysis confirmed that specific ribosomal proteins are associated with chromatin in a histone H1-dependent manner. Overexpression of either histone H1 or ribosomal protein L22 in Drosophila cells resulted in global suppression of the same set of genes, while depletion of H1 and L22 caused up-regulation of tested genes, suggesting that H1 and ribosomal proteins are essential for transcriptional gene repression. Overall, this study provides evidence for a previously undefined link between ribosomal proteins and chromatin, and suggests a role for this association in transcriptional regulation in higher eukaryotes.
Cold-Active Winter Rye Glucanases with Ice-Binding Capacity
Authors: Yaish Mahmoud W.F. , Doxey Andrew C. , McConkey Brendan J. , Moffatt Barbara A. , Griffith Marilyn
Published: July 2006

Extracellular pathogenesis-related proteins, including glucanases, are expressed at cold temperatures in winter rye (Secale cereale) and display antifreeze activity. We have characterized recombinant cold-induced glucanases from winter rye to further examine their roles and contributions to cold tolerance. Both basic β-1,3-glucanases and an acidic β-1,3;1,4-glucanase were expressed in Escherichia coli, purified, and assayed for their hydrolytic and antifreeze activities in vitro. All were found to be cold active and to retain partial hydrolytic activity at subzero temperatures (e.g. 14%–35% at −4°C). The two types of glucanases had antifreeze activity as measured by their ability to modify the growth of ice crystals. Structural models for the winter rye β-1,3-glucanases were developed on which putative ice-binding surfaces (IBSs) were identified. Residues on the putative IBSs were charge conserved for each of the expressed glucanases, with the exception of one β-1,3-glucanase recovered from nonacclimated winter rye in which a charged amino acid was present on the putative IBS. This protein also had a reduced antifreeze activity relative to the other expressed glucanases. These results support the hypothesis that winter rye glucanases have evolved to inhibit the formation of large, potentially fatal ice crystals, in addition to having enzymatic activity with a potential role in resisting infection by psychrophilic pathogens. Glucanases of winter rye provide an interesting example of protein evolution and adaptation aimed to combat cold and freezing conditions.
Rapid, Futile K+ Cycling and Pool-Size Dynamics Define Low-Affinity Potassium Transport in Barley
Authors: Szczerba Mark W. , Britto Dev T. , Kronzucker Herbert J.
Published: July 2006

Using the short-lived radiotracer 42K+, we present a comprehensive subcellular flux analysis of low-affinity K+ transport in plants. We overturn the paradigm of cytosolic K+ pool-size homeostasis and demonstrate that low-affinity K+ transport is characterized by futile cycling of K+ at the plasma membrane. Using two methods of compartmental analysis in intact seedlings of barley (Hordeum vulgare L. cv Klondike), we present data for steady-state unidirectional influx, efflux, net flux, cytosolic pool size, and exchange kinetics, and show that, with increasing external [K+] ([K+]ext), both influx and efflux increase dramatically, and that the ratio of efflux to influx exceeds 70% at [K+]ext ≥ 20 mm. Increasing [K+]ext, furthermore, leads to a shortening of the half-time for cytosolic K+ exchange, to values 2 to 3 times lower than are characteristic of high-affinity transport. Cytosolic K+ concentrations are shown to vary between 40 and 200 mm, depending on [K+]ext, on nitrogen treatment (NO3− or NH4+), and on the dominant mode of transport (high- or low-affinity transport), illustrating the dynamic nature of the cytosolic K+ pool, rather than its homeostatic maintenance. Based on measurements of trans-plasma membrane electrical potential, estimates of cytosolic K+ pool size, and the magnitude of unidirectional K+ fluxes, we describe efflux as the most energetically demanding of the cellular K+ fluxes that constitute low-affinity transport.
Induction of Differentiation in the Shoot Apical Meristem by Transient Overexpression of a Retinoblastoma-Related Protein
Authors: Wyrzykowska Joanna , Schorderet Martine , Pien Stéphane , Gruissem Wilhelm , Fleming Andrew J.
Published: July 2006

The shoot apical meristem contains cells that undergo continual growth and division to generate the building blocks for the aerial portion of the plant. As cells leave the meristem, they undergo differentiation to form specific cell types. Most notably, heterotrophic cells of the meristem rapidly gain autotrophic capability by synthesis and assembly of components of the chloroplast. At the same time, cells undergo enlargement via vacuolation. Despite significant advances in the characterization of transcriptional networks involved in meristem maintenance and leaf determination, our understanding of the actual mechanism of meristem cell differentiation remains very limited. Using a microinduction technique, we show that local, transient overexpression of a retinoblastoma-related (RBR) protein in the shoot apical meristem is sufficient to trigger cells in the meristem to undergo the initial stages of differentiation. Taken together with recent data showing that RBR protein plays a key role in restricting stem cell differentiation in the root apical meristem, our data contribute to an emerging picture of RBR proteins as a central part of the mechanism controlling meristem cell differentiation.
The hpa1 Mutant of Arabidopsis Reveals a Crucial Role of Histidine Homeostasis in Root Meristem Maintenance
Authors: Mo Xiaorong , Zhu Qingyu , Li Xiang , Li Jing , Zeng Qingning , Rong Honglin , Zhang Hanma , Wu Ping
Published: July 2006

Histidine (His) is an essential ingredient for protein synthesis and is required by all living organisms. In higher plants, although there is considerable evidence that His is essential for plant growth and survival, there is very little information as to whether it plays any specific role in plant development. Here, we present evidence for such a role of this amino acid in root development in Arabidopsis (Arabidopsis thaliana) from the characterization of a novel Arabidopsis mutant, hpa1, which has a very short root system and carries a mutation in one of the two Arabidopsis histidinol-phosphate aminotransferase (HPA) genes, AtHPA1. We have established that AtHPA1 encodes a functional HPA and that its complete knockout is embryo lethal. Biochemical analysis shows that the mutation in hpa1 only resulted in a 30% reduction in free His content and had no significant impact on the total His content. It did not cause any known symptoms of His starvation. However, the mutant displayed a specific developmental defect in root meristem maintenance and was unable to sustain primary root growth 2 d after germination. We have demonstrated that the root meristem failure in the mutant is tightly linked to the reduction in free His content and could be rescued by either exogenous His supplementation or AtHPA1 overexpression. Our results therefore reveal an important role of His homeostasis in plant development.
Efficient Virus-Induced Gene Silencing in Arabidopsis
Authors: Burch-Smith Tessa M. , Schiff Michael , Liu Yule , Dinesh-Kumar S.P.
Published: July 2006

Virus-induced gene silencing (VIGS) is a plant RNA-silencing technique that uses viral vectors carrying a fragment of a gene of interest to generate double-stranded RNA, which initiates the silencing of the target gene. Several viral vectors have been developed for VIGS and they have been successfully used in reverse genetics studies of a variety of processes occurring in plants. This approach has not been widely adopted for the model dicotyledonous species Arabidopsis (Arabidopsis thaliana), possibly because, until now, there has been no easy protocol for effective VIGS in this species. Here, we show that a widely used tobacco rattle virus-based VIGS vector can be used for silencing genes in Arabidopsis ecotype Columbia-0. The protocol involves agroinfiltration of VIGS vectors carrying fragments of genes of interest into seedlings at the two- to three-leaf stage and requires minimal modification of existing protocols for VIGS with tobacco rattle virus vectors in other species like Nicotiana benthamiana and tomato (Lycopersicon esculentum). The method described here gives efficient silencing in Arabidopsis ecotype Columbia-0. We show that VIGS can be used to silence genes involved in general metabolism and defense and it is also effective at knocking down expression of highly expressed transgenes. A marker system to monitor the progress and efficiency of VIGS is also described.
A Variable Cluster of Ethylene Response Factor–Like Genes Regulates Metabolic and Developmental Acclimation Responses to Submergence in Rice
Authors: Fukao Takeshi , Xu Kenong , Ronald Pamela C. , Bailey-Serres Julia
Published: July 2006

Submergence-1 (Sub1), a major quantitative trait locus affecting tolerance to complete submergence in lowland rice (Oryza sativa), contains two or three ethylene response factor (ERF)–like genes whose transcripts are regulated by submergence. In the submergence-intolerant japonica cultivar M202, this locus encodes two ERF genes, Sub1B and Sub1C. In the tolerant near-isogenic line containing the Sub1 locus from the indica FR13A, M202(Sub1), the locus additionally encodes the ERF gene Sub1A. During submergence, the tolerant M202(Sub1) displayed restrained leaf and internode elongation, chlorophyll degradation, and carbohydrate consumption, whereas the enzymatic activities of pyruvate decarboxylase and alcohol dehydrogenase were increased significantly compared with the intolerant M202. Transcript levels of genes associated with carbohydrate consumption, ethanolic fermentation, and cell expansion were distinctly regulated in the two lines. Sub1A and Sub1C transcript levels were shown to be upregulated by submergence and ethylene, with the Sub1C allele in M202 also upregulated by treatment with gibberellic acid (GA). These findings demonstrate that the Sub1 region haplotype determines ethylene- and GA-mediated metabolic and developmental responses to submergence through differential expression of Sub1A and Sub1C. Submergence tolerance in lowland rice is conferred by a specific allele variant of Sub1A that dampens ethylene production and GA responsiveness, causing quiescence in growth that correlates with the capacity for regrowth upon desubmergence.
Evaluation of the status of capsicum viruses in the main growing regions of Turkey
Authors: Buzkan N. , Demir M. , Öztekin V. , Mart C. , Çaǧlar B. K. , Yilmaz M. A.
Published: July 2006

The incidence, severity and distribution of six viruses infecting capsicum were determined in the main growing areas of Turkey during the 2004 growing season. The surveys covered 50 randomly selected capsicum fields from four different areas in south‐east Anatolia and the eastern Mediterranean region. 515 samples were individually collected and tested by DAS‐ELISA for Cucumber mosaic cucumovirus (CMV), Alfalfa mosaic alfamovirus (AMV), Potato X potexvirus (PVX), Potato Y potyvirus (PVY), Pepper mild mottle tobamovirus (PMMoV) and Tobacco etch potyvirus (TEV). 64.8% of ELISA‐tested capsicum samples (334 out of 515) were infected by one (41.7%) or more (23.1%) viruses. PVY was the most widespread (26.4%), followed by PVX (25.8%), AMV (25.2%), TEV (23%), PMMoV (9.1%) and CMV (8.3%). Surprisingly high AMV infection was found in three areas (Kahramanmaraş, Şanlıurfa and Gaziantep) where AMV is reported for the first time in this study. However, AMV was not detected in Hatay. PMMoV is another new virus, in all the tested areas.
Eradication of Botryotinia squamosa from the main onion‐producing zone of Argentina in the Lower Rio Colorado Valley
Authors: Delhey R. , Kiehr M. , Izcovich P. , Frascarelli A. , Azpilicueta A. , Wright E. , Lorenzana U. García
Published: July 2006

In 1998, onion transplants raised in La Plata and destined for planting in the main onion‐growing zone of Argentina, the Lower Rio Colorado Valley, were intercepted and found to be infected with the leaf blight fungus Botryotinia squamosa. With the owners’ consent, all the transplanted and not yet transplanted diseased material was destroyed in order to protect the isolated growing zones of southern Argentina from this new disease agent. To date, B. squamosa has been found neither in the Lower Rio Colorado Valley nor in any other onion‐growing zone of southern Argentina.
First report of Rhizopus stolonifer causing inflorescence and fruit rot of Rauvolfia serpentina in India
Authors: Shukla R. S. , Alam M. , Sattar A. , Abdul‐Khaliq  , Singh H. N.
Published: July 2006

Inflorescence and fruit rot caused by Rhizopus stolonifer has appeared for the first time on Rauvolfia serpentina (sarpgandha) in North Indian plains during July–September, 2003. Disease incidence was very high under high humidity and moderate temperature and posing threat to the commercial cultivation of the crop. The initial disease symptoms appear in the form of water‐soaked lesions on the flowers and flower buds which later produce slimy wet rot symptoms leading to premature death and drying of infected parts including the leaves. Pathogenicity of R. stolonifer was established artificially under glasshouse conditions.
Viruses of pome fruit trees in Syria
Authors: Ismaeil F. , Al‐Jabor K. , Myrta A. , Mando M. J. , Al‐Saadoun E. , Hassan M. , Al‐Chaabi S.
Published: July 2006

A survey was conducted to evaluate the sanitary status of pome fruit trees in Syria during spring 2003 and 2004 in 6 governorates: Damascus, Al‐Qunaitara and Al‐Sweida (Southern region), Homs and Hama (Central region) and Latakia (Costal Western region), as the main production areas of pome fruits. Leaf samples from 1077 apples, 54 pears and 14 quince were collected and tested for the presence of Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV) in 70 commercial orchards and 3 varietal collections by ELISA. Results showed that the virus infection rates were 34 and 2% in apple and pear, respectively. Quince trees were found to be virus tested free. ACLSV was prevailing on apple with 34%, whereas ASGV and ApMV were found in 2 and 0.2% of tested trees, respectively. Pear trees were infected only with ACLSV (2%). 21 apples and 15 pears representative budwood samples were indexed by grafting on the following indicators: (i) Malus pumila cvs. Virginia Crab and Radiant for apple and (ii) M. pumila cv. V. Crab and Pyrus communis cv. Nouveau Poiteau for pear. The virus infection rates by woody indexing were much higher than ELISA, Apple stem pitting virus (ASPV) and ASGV were found in 86 and 82% of apple tested samples, whereas they were 80 and 60% of pear tested samples, respectively. Additional RT‐PCR testing carried out for a limited number of samples confirmed the high incidence of ACLSV ASPV, ASGV and the presence of ApMV. This is the first report on pome fruit viruses in Syria, indicating an unsatisfactory sanitary status of the industry. As a consequence, a certification program is recommended for producing locally healthy propagating material.
Molecular characterization of diverse phytoplasmas of subgroups 16SrI‐A, 16SrI‐B, 16SrI‐L, and 16SrI‐M infecting ornamental plants in Lithuania
Authors: Samuitiene M. , Navalinskiene M. , Davis R. E. , Jomantiene R.
Published: July 2006

Trade in ornamental plant species comprises a significant segment in the economies of countries in Europe, North America and Asia. Since the quality of ornamental plants is adversely affected by diseases attributed to phytoplasmas, we surveyed plant collections in botanical gardens and floriculture farms in Lithuania for phytoplasmal diseases. Seventeen ornamental species belonging to nine plant families exhibited disease symptoms including general yellowing and stunting, proliferation of shoots, phyllody, virescence and reduced size of flowers, and reddening of leaves. Analysis of the phytoplasmal 16S rRNA gene sequences amplified by PCR revealed that the plants were infected by phytoplasmas belonging to four distinct subgroups (16SrI‐A, 16SrI‐B, 16SrI‐L, and 16SrI‐M) of group 16SrI (aster yellows phytoplasma group) and indicated the presence of sequence‐heterogeneous 16S rRNA genes in newly recognized strains belonging to subgroups 16Sr‐L and 16SrI‐M. Infections by these diverse phytoplasmas in a wide array of plant species and families suggests that unidentified, polyphagous insect vectors may actively transmit phytoplasmas threatening the Baltic region's ornamental plant industry.
Premières observations de Verticillium dahliae sur olivier en Tunisie
Authors: Triki M. A. , Hassaïri A. , Mahjoub M.
Published: July 2006

Au cours des prospections effectuées dans les oliveraies de la délégation de Mahres (région de Sfax) située au centre‐est de la Tunisie, 12 cas de dépérissement d’oliviers âgés, du cv. ‘Chemlali’ ont été observés dans deux parcelles voisines. Dans ces deux vergers, les oliviers malades sont répartis en foyers. Les investigations au champ et au laboratoire ont permis de mettre en évidence la présence du champignon Verticillium dahliae, qui est ainsi signalé pour la première fois en Tunisie sur olivier.
Development of a Malaria T‐Cell Vaccine for Blood Stage Immunity
Authors: QUAKYI I. A. , TAYLOR D. W. , JOHNSON A. H. , ALLOTEY J. B. , BERZOFSKY J. A. , MILLER L. H. , GOOD M. F.
Published: July 2006

We have defined a strategy for the development of a T‐cell vaccine for blood stage immunity, taking into consideration the central role of T cells and MHC restriction in malaria immune responses. We have used the AMPHI computer algorithm lo identify putative T‐cell epitopes from conserved regions of 11 Plasmodium falciparum asexual stage proteins. Ten of the eleven proteins arc currently candidates for vaccine development. Using this algorithm we selected 22 putative T‐cell epitope peptides und 8 control peptides. These peptides were used to test the T‐cell responses of three defined populations of Caucasians who have (1) recovered from P. falciparum malaria. (2) been exposed, but never clinically infected, (3) never been exposed or infected. Preliminary analysis of our data shows population differences in T‐tell responses to putative T‐cell epitope peptides. Ultimately, these studies will help to identify those T epitopes that can be incorporated into a T‐cell vaccine for protective immunity.
Vaccination of the Vervet Monkey (Cercopithecus aethiops) against Infection with Schistosoma mansoni
Authors: MUMO J. M. , KINOTI G. K.
Published: July 2006

Pilot experiments were carried out to assess the immunizing potential of radiation‐attenuated cercariae of S. mansoni. Groups of 4 monkeys each were vaccinated 4‐5 times at 3‐5‐week intervals using cercariae which had received 10, 20, 40 or 60 krad of gamma radiation. Animals were vaccinated with 1000 or 2000 cercariae per kilogram of body weight. Overall the difference in trans burdens between the vaccinated and unvaccinated groups was highly significant (P > 0.01). The highest level of protection achieved was 44.4%. This was in monkeys which were immunized live times with 2000, 20‐krad cercariae at 3–4‐week intervals. Protection levels of 33.3%, 36.6% and 37.0% were achieved in groups which had received, respectively, 1000 20‐krad cercariae, 1000 10‐krad cercariae, 2000 40‐krad cercariae and 2000 60‐krad cercariae. Vaccination reduced faecal egg counts markedly and intestinal tissue egg cotints by 20–40%. Antischistosomular antibody was detectable in vitro 3 weeks after the first vaccination. Schistosomule kill rates of up to 60% were observed in vitro.
Immune Responses after Treatment for Schistosoma mansoni Infections
Authors: KIMANI G. , CHUNGE C. N. , GACHIHI G. , KAMAU T. , MUNGAI B. , MKOJI G. M.
Published: July 2006

The changes in the immune responses of patients before and at 3 weeks after treatment with anti‐schistosomal drugs were investigated. Lymphocyte responses to Concanavalin A and to worm antigens were inhibited after treatment, whereas responses to cercarial and egg antigens remained unchanged. Eosinophil levels were significantly elevated after treatment and were positively correlated with the increase in anti‐worm antibodies (r= 0.587), and negatively associated with anti‐egg antibodies (r= ‐0.727). Although the eosinophil‐dependent cytotoxicity to schistosomula was not significantly enhanced after treatment, some increased killing was evident in half the patients (7/15). On the other hand, the ability of adherent mononuclear cells to stimulate eosinophil functions was markedly enhanced by treatment (P < 0.001). These studies suggest that treatment may enhance some of the potentially protective host's immune mechanisms.
Suppression of T‐Cell Responsiveness during Tsetse‐Transmitted Trypanosomiasis in Cattle
Authors: SILEGHEM M. , FLYNN J. N.
Published: July 2006

In the present study, we demonstrate that lymph node cells from cattle infected with T. congolense through tsetse fly challenge were unable to proliferate in vitro following activation with the T‐cell mitogen Concanavalin A. This was associated with a simultaneous suppression of interleukin 2 (IL‐2) production and interleukin 2 receptor (IL‐2R) expression. However, the capacity of the cells to secrete interferon γ following the mitogenic activation was not affected by the infection.
Isolation and Properties of 600‐kDa and 23‐kDa Haemolymph Proteins from the Tsetse Fly, Glossina morsitans: their Possible Role as Biological Insecticides
Authors: OCHANDA J. O. , OSIR E. O. , NGUU E. K. , OLEMBO N. K.
Published: July 2006

The haemolymph of the tsetse fly. Glossina morsitans morsilans. contains a high (lipophorin) and a low molecular weight protein of high densities. I. 11 and 1.29 g/ml. respectively. The purification of the proteins was achieved by a combination of density gradient ultracentrifugation and reported gel permeation chromatography. The lipophorin is of high molecular weight (Mr∼ 600.000) and consists of two apoproteins. apolipophorin I (M Mr∼250.250,000) and apolipo‐phorin II (M Mr∼ 80.000) both of which are glycosylated. Lipophorin also has a pi of 6.1. However, electrophoresis under non‐denaturing and denaturing conditions showed the low molecular weight protein to be a single polypeptide chain (Mr∼ 23,000). Amino acid analysis revealed a relatively high content of the acidic amino acids as well as serine and glycine. The protein contained lipids as shown by Sudan Black staining but was unglycosylated. Using rabbit antiserum against the isolated protein in immunodiffusion and immunoblotting experiments, no cross‐reactivity was detected with haemolymph samples from insects representing six orders. In conclusion, the finding of lipophorin suggests that, although flies primarily utilize proline for their energy needs, there is an active transport mechanism for the supply of lipid requirements. However, the results for the low molecular weight protein indicate that the protein is unique to Glossina, suggesting that it may have an important role in the physiology of this insect and is therefore a significant target for vector management.
IFN‐γ and Delayed‐Type Hypersensitivity are Associated with Cutaneous Leishmaniasis in Vervet Monkeys following Secondary Rechallenge with Leishmania major
Authors: OLOBO J. O. , REID G. D. F. , GITHURE J. I. , ANJILI C. O.
Published: July 2006

IFN‐γ levels and delayed‐type hypersensitivity (DIM) responses were evaluated in vervet monkeys, following secondary infection with leishmania major (L. major). The animals had previously been vaccinated with leishmanial antigen, exposed to a primary infection and allowed to self‐cure. Supernatants of peripheral blood mononuclear cell (PBMC) cultures, stimulated with either L. major antigen or Concanavalin A (Con A), were examined for the presence of IFN‐γ in a double sandwich enzyme‐linked immunosorbent ASSAY (ELISA). Significant levels of IFN‐γ were detected during active disease and following Self‐cure in both antigen and Con A supernatants Higher levels of IFN‐y were, however, present during active disease as compared with after self‐cure. Positive and strong DTH responses were elicited in all experimental animals, following intradermal injection of fixed promastigotes (5×107/animal) before rechallenge, during active infection and following self‐cure. Again, strongest DTH responses were obtained during active infection as compared with the other sampling point

There was a correlation between IFN‐γ levels and DTH responses. It was concluded that IFN‐γ secretion and positive DTH responses are associated with secondary L. major infection and represent specific immunological correlates of protection in this disease model.
Anti‐Onchocerca volvulus Immunoglobulin Subclass Response in Children from Sierra Leone
Authors: GBAKIMA A. A. , IBRAHIM M. S. , SCOTT A. L.
Published: July 2006

The humoral immune responses of a paediatric population of 224 children, 2‐15 years of age, residing in an onchocerciasis endemic area of Sierra Leone, were studied to gain information that may be useful in the serodiagnosis of prepatent and low‐level infections with Onchocerca volvulus. The antigen‐specific levels of IgG and IgG4 were determined and evaluated in the context of the parasitological status of the child. Over 87% of the microfilaria‐negative children had significant levels of antigen‐specific antibodies against O. volvulus, suggesting that a large percentage of this paediatric population were harbouring prepatent or low‐level infections. Over 60% of the children in the group that had detectable numbers of microfilariae in skin snips had elevated levels of O. vlovulus‐specific IgG4. In contrast, only 23% of the microfilaria‐negative children had detectable IgG4 responses. The results presented here indicate that measures of O. volvulus‐specific IgG4 may be a useful indicator of the parasitological status of children during the very early stages of onchocerciasis.
Cloning and Sequencing of Hepatitis B Virus Pre‐S and S Gene Regions
Authors: CHIRARA M. M. , CHETSANGA C. J.
Published: July 2006

The polymerase chain reaction (PCR) was used to amplify the pre‐S1, pre‐S2 and S gene regions of hepatitis B virus (HBV). Sera from three different patients were used as the source of HBV DNA. The resulting 1.2‐kb amplification product was cloned into the plasmid pI B130. Restriction enzyme analysis revealed that there are two BamHI sites located about 300 bp apart within the S gene. DNA sequencing revealed a greatest homology to the HBV adw subtype.
Herpes Zoster Ophthalmicus: an Early Pointer to HIV‐1 Positivity in Young African Patients
Authors: PALEXAS G. N. , WELSH N. H.
Published: July 2006

We studied prospectively 30 patients, seen over 10 months, who had herpes zoster ophthalmicus (HZO) and who were classified by age, sex, ophthalmological observations and HIV‐1 status. Of patients who presented with HZO, 40% were HIV positive, and the majority were less than 40 years of age. The clinical anifestation of HZO has a high positive predictive value for HIV positivity in young patients with this viral infection.
The Detection of Human Papillomaviruses in Cervical Biopsies by Immunohistochemistry and In Situ Hybridization
Authors: SHEPHERD P. , LUNNY D. , BROOKES R. , PALMER T. , McCANCE D.
Published: July 2006

The presence of human papillomavirus (HPV) types 6, 16 and 8 in cervical biopsies can be detected by an immunoperoxidase technique using type‐restricted monoclonal antibodies raised against fusion proteins representing the L1 major capsid proteins of these three HPV types. In a retrospective study (n= 54) we have used these antibodies and biotinylated DNA probes of HPV 6.16 and 18 lo detect and type HPV in formalin‐fixed material from the cervix. The biopsies were classified histologically into normals, wart infections without dysplasia, cervical intraepithelial neoplasia (CIN)and squamous cell carcinomas. Antibody staining showed that 22% of all CIN was positive for HPV 16and 40% of cervical warts were positive for HPV 6, 16 and 18, There was no HPV capsid protein detected in the normals and squamous cell carcinomas using these antibodies, whereas 25% of the tumours were positive for HPV 16 by in situ hybridization. Sections of cervical warts and CIN positive for HPV types by in situ hybridization were also positive by antibody staining which suggests that both techniques are detecting replicating virus. We feel these two techniques complement each other in detection and typing of HPV in cervical biopsies from patients with active disease.
'Silent’HIV Infection among Wives of Seropositive HIV Carries in the Ethiopian Community in Israel
Authors: JEHUDA‐COHEN T. , VONSOVER A. , MILTCHEN R. , BENTWICH Z.
Published: July 2006

We have previously described the phenomenon of 'silent HIV carriers', i.e. individuals with HIV specific immunity and a positive PCR for HIV‐1, yet HIV seronegative. In the present study, we have looked for such 'silent’carriers among wives of individuals infected with HIV in Africa (Ethiopia). In addition to determining HIV serology, peripheral blood mononuclear cells (PBMC) were tested by PCR for HIV‐1 and for their ability to generate specific antibodies to HIV upon polyclonal B‐cell activation (P‐BAT). Out of 16 wives so tested, three were HIV seropositive and among the 13 seronegatives, eight were P‐BAT positive and five were both P‐BAT and PCR positive. These findings suggest that (1) 'silent’HIV carriers may indeed be present in African populations; (2) interpretation of the 'silent’carrier phenomenon is not clear and will depend on clinical follow‐up and the ability to culture virus from such carriers; and (3) results of HIV serology in this population and probably in other African populations should be viewed with caution.
Specific IgG Subclass Antibody Levels and Phagocytosis of Serotype 14 Pneumococcus Following Immunization
Authors: KANIUK A. St. C. , LORTAN J. E. , MONTEIL M. A.
Published: July 2006

Complement and specific antibody directed against capsular polysaccharide are necessary for efficient phagocytosis of pneumococci. In normal adults, specific antibody to pneumococci is predominantly of the IgG2 subclass. However, the role of IgG2 in bacterial clearance is debatable. We therefore decided to investigate the relationship between specific IgG subclass antibody levels and phagocytosis of serotype 14 pneumococcus, before and after immunization with a pneumococcal capsular polysaccharide vaccine. Specific IgG subclass antibody was measured by an ELISA technique and the effect of serum on phagocytosis of radiolabelled pneumococci by normal polymorphs was determined. We found that in the presence of complement, phagocytosis correlated significantly with both specific IgGl and IgG2 antibody titres(r= 0.547, P= 0.002 and r= 0.464. P= 0.009, respectively). However, in decomplemented sera, the correlation with IgGl antibody was lost, whereas that with IgG2 antibody was strengthened (r= 0.641. P= < 0.001). The possibility that IgG2 binds to receptors on polymorphs should be considered.
Anaplasmosis in Uganda. I. Use of Dried Blood on Filter Paper and Serum Samples for Serodiagnosis of Anaplasmosis—a Comparative Study
Authors: SSENYONGA G. S. Z. , MONTENEGRO‐JAMES S. , KAKOMA I. , HANSEN R.
Published: July 2006

The suitability of blood collected on filter papers in comparison with corresponding conventional serum samples in the diagnosis of bovine anaplasmosis was studied using the Complement Fixation Test (CFT), DOT‐ELISA, Western immunoblot and Rapid Card Agglutination Test (RCAT). Dried blood on Whatman filter paper no. I was eluted in 1.8 ml of PBS 0.05% Tween 20 given an initial dilution of 1:100.

The reactivity in both DOT‐ELISA and Western immunoblotting was similar to that obtained with the sera diluted 1:100. Filter paper samples gave lower reactivity in all the tests as compared with corresponding serum samples. There was no significant difference in the reactivity between the eluates from filter papers stored at room temperature and those stored at 4°C. Storage at room temperature did not significantly affect reactivity for up to 6 months. Eluates from filter papers stored for 6 months at room temperature continued to give similar reactivity to those from freshly prepared filter papers in both DOT‐ELISA and Western blot, and in the Rapid Card Agglutination Test.

It is concluded that collecting blood on filter papers is a suitable technique for large‐scale screening and for seroepidemiological studies on anaplasmosis, and offers many advantages especially in developing countries where transport and cold chain facilities are a major constraint.
Options for Immunocontraception and Issues to be Addressed in the Development of Birth Control Vaccines
Authors: GRIFFIN P. D.
Published: July 2006

Although the number of family planning methods currently available to couples has never been greater, the range and type of options are still not adequate to meet the widely varying personal needs and demands of individuals worldwide. Birth control vaccines offer a number of theoretical attractions although the development, preclinical and clinical testing of such vaccines pose a number of unique problems requiring novel solutions. If the on‐going studies in this area are successful, a valuable new family planning method may be available by the end of the current decade.
Anti‐Sperm and Anti‐Ovum Vaccines: the Selection of Candidate Antigens and the Outcome of Preclinical Studies
Authors: ISAHAKIA M. A. , BAMBRA C. S.
Published: July 2006

A clear conceptual basis for anti‐sperm and other modes of immunological birth control exists in spite of the limited basic research done on surface antigens of sperm or egg. In the normal physiological condition, the immune system does not respond to sperm, egg or fetus. Compared with anti‐egg or anti‐fetus immunocontraception, an anti‐sperm vaccine has two theoretical advantages. First it would work in both males and females; second, it would not raise problems of autoimmunity in the female if a sperm‐specific protein is used.

However, for the development of such contraceptive vaccines the following scientific questions need to be resolved: (1) what surface protein to use as an antigen: (2) what adjuvant to use in humans for an anti‐fertility vaccine: (3) how to maintain a high titre; (4) how the contraceptive effect will be terminated; and (5) what are the potential side‐effects.
Anti‐LHRH and Anti‐Pituitary Gonadotropin Vaccines: their Development and Clinical Applications
Authors: THAU R.
Published: July 2006

Active immunization against hormones involved in the regulation of reproduction is a promising approach to immunocontraception. The hypothalamic peptide, LHRH, controls the synthesis and release of the pituitary gonadotropins, LH and FSH, which regulate gonadal steroidogenesis, sperm production, follicular development and ovulation. Immunizing female primates against LHRH or LH induces infertility, but also disrupts the menstrual cycle. Immunization against the β subunit of the placental hormone, chorionic gonadotropin (hCG), or its fragment prevents pregnancy without interfering with menstrual cycles or ovulation. hCG vaccines have reached the stage of clinical trials.

FSH and LHRH have been tested for immunocontraception in male primates. While active as well as passive immunization against FSH reduced spermatogenesis severely, azoospermia could not be achieved consistently. Immunization against LHRH effectively suppressed spermatogenesis in rats and rabbits. Normal sexual behaviour was maintained by concomitant androgen administration. Fertility was restored when antibody titres declined and no adverse effects were observed. A number of LHRH vaccine preparations are being tested in men in several countries, including the United States. Since the LHRH vaccine reduces serum testosterone levels the first clinical studies involve men with prostate cancer. These trials will be followed by immunization of normal men if the antibody response is sufficient and no adverse effects are observed.
Anti‐Trophectoderm Vaccines: Rationale and Methods used for Antigen Identification and Selection
Authors: BAMBRA C.S.
Published: July 2006

Trophoblast, forming a continuous interface at the maternal‐fetal junction, is of considerable interest to biologists. An area of recent research is the search for trophoblast‐specific antigens. It is applications such as in development of contragestational vaccines. To be acceptable for humans such a vaccine will need to be effective before the completion of implantation and appearance of the primitive streak about 14days after fertilization. This will not alter the menstrual cycle or the time of menses. Vaccines having a later effect resulting in termination of pregnancy after this time would be considered a bortifacients. Although logistical and ethical considerations necessitated the use of post‐implantation human trophoblast in WHO Birth Control Vaccine studies, the antigens isolated from such tissues would need to be expressed and be detectable on the surface of pre–implantation trophectoderm if they are to represent appropriate candidates for vaccine development. The criteria for identification and selection of these antigens will be reviewed.
Future Perspectives for Vaccine Development
Authors: STEVENS V. C.
Published: July 2006

The successful development of an anti‐fertility vaccine necessitates overcoming obstacles in eliciting an immune response to self species body constituents. The feasibility of accomplishing this task has been demonstrated for certain antigens described in this workshop: however, additional vaccine candidate antigens may yet be revealed from the application of recent advances in molecular biology. Improvements in vaccine design are likely to occur from discovery of more appropriate epitopes on targeting antigens, new carrier molecules for lerminating immunological tolerance, expression of vaccine antigens in suitable live vectors, the co‐immunization with more than one antigen, the use of safer and/or more effective adjuvants and vehicles, more efficient immunization by targeting antigens to specific lymphoid cells, and the development of superior vaccine delivery systems. Research directed to restricting the immune response to the gential tract and to intentionally reverse the effects of immunization will likely be pursued in the future.

All of these areas need to be addressed if vaccines are to be developed that are not only safe and effective but also highly acceptable as birth control methods.
Immunological Techniques in and for Developing Countries
Authors: WRIGHT E.P.
Published: July 2006

A review is given of the problems and challenges in using immunological techniques in and for developing countries.
Immunoblot Analysis of Sera from Ethiopian Cutaneous Leishmaniasis by Antibody Class
Authors: MENGISTU G. , AKUFFO H. , FEHNIGER T. E.
Published: July 2006

We have determined the specificity of the classes of anti‐leishmanial antibodies which are delectable in serum from patients with active cutaneous leishmaniasis. On immunoblots, differences exist in the patterns of antigen recognition by IgG, IgM, IgA and IgE antibodies present in localized cutaneous leishmaniasis (LCL) and diffuse cutaneous leishmaniasis (DCL) patient serum. Each class of antibody showed differing patterns of banding to the various molecular species of parasite antigens. There was significant variation in the specificities of the IgG antibody reactivities between individual patients. The patterns of IgM binding were generally homogeneous and restricted to antigens with Mr 40 kDa. The only class of anti‐Leishmainia antibodies which showed shared patterns of common antigen recognition by all of the patients studied were IgA antibodies. The reactivities of IgE antibodies encompassed two antigens of Mr 36 and 46‐48 kDa which were not recognized by any of the other isotypes. Such antibody class associated reactivity may be useful in the design of serodiagnostic assays for the detection of Leishmania infection or other infectious agents.

Gennene Mengistu, Department of Infectious Diseases, K. Karolinska Institute, Huddinge Hospital, 14186 Huddinge, Sweden
Serum, Disc and Egg ELISA for the Serodiagnosis of Salmonella gallinarum and S. enteritidis Infections in Chickens⋆
Authors: MINGA U. M. , WRAY C. , GWAKISA P. S.
Published: July 2006

An ELISA was evaluated for the serodiagnosis of fowl typhoid and paratyphoid due to Salmonella enteritidis in chickens. The hot phenol: water lipopolysaccharide (LPS) extract of Salmonella was used as the antigen. Chicken serum, eggs and discs impregnated with chicken blood were tested for the presence of antibodies against Salmonella factor‘O’9 antigen. The substrate and chromogen used were hydrogen peroxide and orthophenylenediamine respectively. Serological results from the experimentally and naturally infected chickens showed close agreement between the conventional Serum Tube Agglutination Test (SAT) and serum ELISA while serum ELISA results were in close agreement with the egg and disc ELISA results. It was noted that ELISA was highly sensitive, convenient and versatile. It is concluded that ELISA, especially disc ELISA, ought to replace SAT for seroscreening chickens against S. gallinarum and other Salmonella Group D infections.
Cytokine Responses to Parasite Antigens: In Vitro Cytokine Production to Promastigotes of L. aethiopica by Cells from Non‐Leishmania Exposed Donors may Influence Disease Establishment
Authors: AKUFFO H. O.
Published: July 2006

The various cytokine responses associated with stimulation by parasites is discussed with emphasis on Leishmania parasites.

Cells from normal individuals can respond to Leishmania antigen in vitro but the State of the antigen used for stimulation influences the outcome. We have used cells from non‐Leishmania exposed donors and stimulated them in vitro with variously treated promastigotes of L. aethiopica. The levels of some cytokines released into the supernatant were measured. All the Leishmania preparations tested induced high levels of IL‐6. whereas IFN‐γ production to the different stimuli was variable in the individual donors. The ability of these supernatants to inhibit intracellular forms of L. aethiopica was sometimes stronger in L. aethiopica‐induced than in PHA‐induced cultures. Such strong non‐Leishmania specific responses, if they exist in vivo, may influence whether disease is established when the host encounters Leishmania parasites.