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PubMed2005

Co-infection of Mycobacterium tuberculosis and Mycobacterium leprae in human archaeological samples: a possible explanation for the historical decline of leprosy.

Both leprosy and tuberculosis were prevalent in Europe during the first millennium but thereafter leprosy declined. It is not known why this occurred, but one suggestion is that cross-immunity protected tuberculosis patients from leprosy. To investigate any relationship between the two diseases, selected archaeological samples, dating from the Roman period to the thirteenth century, were examined for both Mycobacterium leprae and Mycobacterium tuberculosis DNA, using PCR. The work was carried out and verified in geographically separate and independent laboratories. Several specimens with palaeopathological signs of leprosy were found to contain DNA from both pathogens, indicating that these diseases coexisted in the past. We suggest that the immunological changes found in multi-bacillary leprosy, in association with the socio-economic impact on those suffering from the disease, led to increased mortality from tuberculosis and therefore to the historical decline in leprosy.

Bone and Bones↗
PubMed1994

Vaccination against gastrointestinal nematodes of sheep using purified secretory acetylcholinesterase from Trichostrongylus colubriformis--an initial pilot study.

Purified secretory acetylcholinesterase (sAChE) from Trichostrongylus colubriformis was used as a candidate vaccine against mixed T. colubriformis, Haemonchus contortus and C. oncophora challenge infections of sheep. Cross species protection was achieved with an average reduction in worm burden of all species of 31%, rising to 58% in individual cases. There was no consistent reduction in faecal egg counts and increases in anti-T. colubriformis sAChE IgG antibody levels following vaccination were modest. We suggest that improved antigen delivery systems will result in increased host protection.

Acetylcholinesterase↗
PubMed1998

The use of synthetic peptides in the design of a consensus sequence vaccine for Pseudomonas aeruginosa.

Pseudomonas aeruginosa employs pili to mediate adherence to epithelial cell surfaces. Research has shown that the C-terminal region of the pilin monomer contains the epithelial cell binding domain, which is semiconserved in seven different strains of this bacterium. Antibodies to this region of the pilin molecule are also able to block and prevent the infection process. As there is a degree of sequence and structural homology in the C-terminal region and all strains examined have been shown to bind to the same cell surface receptor, we reasoned that it should be possible to produce a synthetic peptide consensus sequence which would provide cross-reactive antiserum from a single peptide immunogen inhibiting the adherence of the known strains of P. aeruginosa. In this article we examine the cross-reactivity of five rabbit polyclonal antisera. One has been raised against the cell-surface receptor binding domain of native PAK strain pilin (residues 128-144) while the others have been raised to analogues of this region. Analysis of the cross-reactivity of these antisera, using competitive ELISA assay, has shown that it is possible to manipulate the amino acid sequence of a peptide immunogen to generate antiserum, which exhibits enhanced cross-reactivity to various strains of P. aeruginosa. Furthermore, when this peptide is conjugated to tetanus toxoid and used to vaccinate mice it provided cross-reactive protection against heterologous challenge with PAO strain bacteria. The results of these experiments are analyzed, and the applicability of our hypothesis and the implications of this approach to the design of a strain-independent consensus vaccine for immunization against Pseudomonas aeruginosa are discussed.

Amino Acid Sequence↗
PubMed1996

An example of non-conservation of oligomeric structure in prokaryotic aminoacyl-tRNA synthetases. Biochemical and structural properties of glycyl-tRNA synthetase from Thermus thermophilus.

Glycyl-tRNA synthetase (Gly-tRNA synthetase) from Thermus thermophilus was purified to homogeneity and with high yield using a five-step purification procedure in amounts sufficient to solve its crystallographic structure [Logan, D.T., Mazauric, M.-H., Kern, D. & Moras, D. (1995) EMBO J. 14, 4156-4167]. Molecular-mass determinations of the native and denatured protein indicate an oligomeric structure of the alpha 2 type consistent with that found for eukaryotic Gly-tRNA synthetases (yeast and Bombyx mori), but different from that of Gly-tRNA synthetases from mesophilic prokaryotes (Escherichia coli and Bacillus brevis) which are alpha 2 beta 2 tetramers. N-terminal sequencing of the polypeptide chain reveals significant identity, reaching 50% with those of the eukaryotic enzymes (B. mori, Homo sapiens, yeast and Caenorhabditis elegans) but no significant identity was found with both alpha and beta chains of the prokaryotic enzymes (E. coli, Haemophilus influenzae and Coxiella burnetii) albeit the enzyme is deprived of the N-terminal extension characterizing eukaryotic synthetases. Thus, the thermophilic Gly-tRNA synthetase combines strong structural homologies of eukaryotic Gly-tRNA synthetases with a feature of prokaryotic synthetases. Heat-stability measurements show that this synthetase keeps its ATP-PPi exchange and aminoacylation activities up to 70 degrees C. Glycyladenylate strongly protects the enzyme against thermal inactivation at higher temperatures. Unexpectedly, tRNA(Gly) does not induce protection. Cross-aminoacylations reveal that the thermophilic Gly-tRNA synthetase charges heterologous E. coli tRNA(gly(GCC)) and tRNA(Gly(GCC)) and yeast tRNA(Gly(GCC)) as efficiently as T. thermophilus tRNA(Gly). All these aminoacylation reactions are characterized by similar activation energies as deduced from Arrhenius plots. Therefore, contrary to the E. coli and H. sapiens Gly-tRNA synthetases, the prokaryotic thermophilic enzyme does not possess a strict species specificity. The results are discussed in the context of the three-dimensional structure of the synthetase and in the view of the particular evolution of the glycinylation systems.

Amino Acid Sequence↗
PubMed2005

A novel thiol antioxidant that crosses the blood brain barrier protects dopaminergic neurons in experimental models of Parkinson's disease.

It is believed that oxidative stress (OS) plays an important role in the loss of dopaminergic nigrostriatal neurons in Parkinson's disease (PD) and that treatment with antioxidants might be neuroprotective. However, most currently available antioxidants cannot readily penetrate the blood brain barrier after systemic administration. We now report that AD4, the novel low molecular weight thiol antioxidant and the N-acytel cysteine (NAC) related compound, is capable of penetrating the brain and protects neurons in general and especially dopaminergic cells against various OS-generating neurotoxins in tissue cultures. Moreover, we found that treatment with AD4 markedly decreased the damage of dopaminergic neurons in three experimental models of PD. AD4 suppressed amphetamine-induced rotational behaviour in rats with unilateral 6-OHDA-induced nigral lesion. It attenuated the reduction in striatal dopamine levels in mice treated with 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP). It also reduced the dopaminergic neuronal loss following chronic intrajugular administration of rotenone in rats. Our findings suggest that AD4 is a novel potential new neuroprotective drug that might be effective at slowing down nigral neuronal degeneration and illness progression in patients with PD.

Animals↗
PubMed2006

Use of an Actinobacillus pleuropneumoniae multiple mutant as a vaccine that allows differentiation of vaccinated and infected animals.

Vaccination against Actinobacillus pleuropneumoniae is hampered by the lack of vaccines inducing reliable cross-serotype protection. In contrast, pigs surviving natural infection are at least partially protected from clinical symptoms upon reinfection with any serotype. Thus, we set out to construct an attenuated A. pleuropneumoniae live vaccine allowing the differentiation of vaccinated from infected animals (the DIVA concept) by successively deleting virulence-associated genes. Based on an A. pleuropneumoniae serotype 2 prototype live negative marker vaccine (W. Tonpitak, N. Baltes, I. Hennig-Pauka, and G.-F. Gerlach, Infect. Immun. 70:7120-7125, 2002), genes encoding three enzymes involved in anaerobic respiration and the ferric uptake regulator Fur were deleted, resulting in a highly attenuated sixfold mutant; this mutant was still able to colonize the lower respiratory tract and induced a detectable immune response. Upon a single aerosol application, this mutant provided significant protection from clinical symptoms upon heterologous infection with an antigenically distinct A. pleuropneumoniae serotype 9 challenge strain and allowed the serological discrimination between infected and vaccinated groups.

Actinobacillus Infections↗
PubMed1985

Expression of protective and cardiac tissue cross-reactive epitopes of type 5 streptococcal M protein in Escherichia coli.

The immunochemical properties of type 5 M protein antigens that were expressed in Escherichia coli K-12 by recombinant lambda bacteriophages isolated from a gene bank of serotype 5 Streptococcus pyogenes have been analyzed in detail. M proteins from partially purified bacteriophage lysates displayed precipitin lines of identity with a purified peptic extract of type 5 M protein (pep M5) in immunodiffusion assays. Immunoblot analyses of the M protein-positive lysates demonstrated that the cloned M protein component resided in five polypeptides with relative molecular weights of 57,900 (57.9K), 55.4K, 52.9K, 40.0K, and 32.6K. The hybrid lambda phage (lambda M5)-produced M protein contained immunoprotective epitopes; lambda M5 protein inhibited opsonization of type 5 streptococci by pep M5 antibodies, and antiserum raised against lambda M5 lysates opsonized type 5 streptococci. Each of the five antigenic polypeptides of the recombinant phage M protein also shared epitopes with human heart tissue, as demonstrated by the reactivity of immunoblots of lambda M5 antigens separated on sodium dodecyl sulfate gels with anti-pep M5 antibodies absorbed to and eluted from human heart sarcolemmal membranes. Moreover, antiserum raised against the lambda M5 lysates reacted with sarcolemmal membrane proteins with relative molecular weights of 200K, 59K, 55K, 53K, and 27K as determined by immunoblot analyses. These results demonstrate that the structural gene coding for type 5 streptococcal M protein which was inserted into lambda DNA expresses immunoprotective epitopes, some of which are shared with human heart tissue.

Antigens, Bacterial↗
PubMed2005

Influenza type A virus escape mutants emerge in vivo in the presence of antibodies to the ectodomain of matrix protein 2.

The ectodomain of matrix protein 2 (M2e) of human influenza type A virus strains has remained remarkably conserved since 1918. Because M2e-specific immunity has been shown to decrease morbidity and mortality associated with influenza virus infection in several animal models and because natural infection and current vaccines do not appear to induce a good M2e-specific antibody (Ab) response, M2e has been considered as potential vaccine for inducing cross-reactive protection against influenza type A viruses. The high degree of structural conservation of M2e could in part be the consequence of a poor M2e-specific Ab response and thus the absence of pressure for change. To assess this possibility, we studied the course of infection in SCID mice in the presence or absence of passive M2e-specific monoclonal Abs (MAbs). We found that virus mutants with antigenic changes in M2e emerged in 65% of virus-infected mice treated with M2e-specific but not control MAbs. However, the diversity of escape mutants was highly restricted since only two types were isolated from 22 mice, one with a proline-to-leucine and the other with a proline-to-histidine interchange at amino acid position 10 of M2e. The implications of these findings for the use of M2e as a broadly protective vaccine are discussed.

Amino Acid Sequence↗
PubMed2004

Centralized immunogens as a vaccine strategy to overcome HIV-1 diversity.

Genetic variation of HIV-1 represents a major obstacle for AIDS vaccine development. With the amino acid sequence divergence as high as 30% in envelopes between different subtypes among HIV-1 group M viruses, it is unlikely that cross-subtype protection will occur equally well among all subtypes. Computer programs have been used to generate 'centralized' HIV gene sequences: consensus, ancestor or center of the tree. These sequences can decrease the genetic distances between the 'centralized' and wild-type gene immunogens to half of those between any wild-type immuongens to each other. Recent studies demonstrated that an artificial group M consensus env gene is equidistant from any subtype and recombinants. It is biologically functional and preserves antigenicity similar to contemporary Env proteins. Most importantly, the group M consensus Env immunogen can elicit both T- and B-cell responses to wild-type HIV-1 isolates.

AIDS Vaccines↗
PubMed2004

A prospective cross-over field trial shows protection of lemon eucalyptus extract against tick bites.

Ixodes ricinus can transmit several microorganisms, out of which Borrelia burgdorferi and tick-borne encephalitis (TBE) virus are the most important pathogens in humans. A lemon eucalyptus extract (Citriodiol) has been shown to be a natural repellent against mosquitoes, stable flies, and midges. We have investigated whether the use of the extract would reduce the number of attached I. ricinus ticks in humans. A volunteer sample of 111 individuals was recruited among healthy, outdoor active adults living in two highly I. ricinus-infested areas. They were randomly divided into two groups: one group applied the Citriodiol spray daily for 2 wk to the lower extremities, whereas the other group was instructed not to use any type of repellent on any part of the body. After 2 wk, the scheme was reversed. All volunteers filled in a daily diary, giving information about outdoor activities and the number of observed, attached, or not yet attached ticks, including the anatomical location of the ticks found. Forty-two attached ticks were reported during the weeks when the Citriodiol spray was used, and 112 were reported when it was not. The median number of reported attached ticks per person decreased from 1.5 (range, 0-9) to 0.5 (range, 0-2; P < 0.05) during the weeks when the repellent was used. The number of reported attached ticks noted below the waist was 13/42 (31%) during the period when the spray was used and 73/112 (65%) when no spray was used (P < 0.001). No evident redistribution of attached ticks from protected areas to unprotected areas was seen. Citriodiol may become a useful means in reducing the number of tick bites and thereby tick-borne infections, although additional studies are warranted.

Adult↗
PubMed1999

[In Process Citation]

To prevent disturbances of blood gas-transport function in hemorrhagic shock, we used cross-over protective effect of adaptation to short-term immobilisation stress. Adaptation of rats to stress was associated with a rise in baseline arterial pressure, hematocrit, oxygen capacity and concentration of buffer bases in arterial blood, pH in venous blood; fall in PO2, PCO2, P50. Stress-adapted rats appeared more resistant to blood loss. Gas transport 1 hour after hemorrhage was better than in non-adapted animals. In hemorrhagic shock, the adapted animals demonstrated more active compensatory reactions in low hypoxic damage to the tissues. 2.5-h survival after start of bleeding in control animals made up 35%, in the group of adapted animals--67%. Thus, adaptation to short-term immobilization stress is a non-pharmacological method to prevent hemorrhagic shock.

Journal Article↗
PubMed2001

Water quality response to riparian restoration in an agricultural watershed in Vermont, USA.

Achievement of management goals for Lake Champlain (Vermont/New York, USA and Quebec, Canada) will require reduction of agricultural phosphorus loads, the dominant nonpoint source in the Basin. Cost-effective phosphorus reduction strategies need reliable treatment techniques beyond basic cropland and waste management practices. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluates the effectiveness of livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of nutrients, sediment, and bacteria in surface waters. Treatment and control watersheds in northwestern Vermont have been monitored since 1994 according to a paired-watershed design. Monitoring consists of continuous stream discharge recording, flow-proportional sampling for total P, total Kjeldahl N, and total suspended solids, grab sampling for indicator bacterial, and land use/agricultural monitoring. Strong statistical calibration between the control and treatment watersheds has been achieved. Installation of riparian fencing, protected stream crossings, and streambank bioengineering was completed in 1997. Early post-treatment data suggest significant reduction in P concentrations and loads and in bacteria counts in the treated watershed. Monitoring is scheduled to continue through 2000.

Agriculture↗
PubMed2002

Phosphorus reductions following riparian restoration in two agricultural watersheds in Vermont, USA.

Achievement of management goals for Lake Champlain (Vermont/New York, USA and Quebec, Canada) will require significant reductions of phosphorus (P) loads from agriculture, the dominant diffuse source in the basin. Cost-effective P reduction strategies must be based on reliable treatment techniques beyond basic erosion control and animal waste storage practices. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluates the effectiveness of low-cost livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of diffuse-source pollutants from grazing land at the watershed level. Treatment and control watersheds in northwestern Vermont have been monitored since 1994 according to a paired-watershed design. Monitoring includes continuous stream discharge recording, flow-proportional sampling for total P and other pollutants, and documentation of land use and agricultural management activities. Strong statistical calibration between the control and treatment watersheds has been achieved. Landowner participation in the land treatment program was entirely voluntary and all treatments were 100% cost-shared by the project and cooperators. Installation of riparian fencing, alternative water supplies, protected stream crossings, and streambank bioengineering was completed in 1997 at a cost of less than US$40,000. The paired-watershed design was effective in controlling for the influence of extreme variations in precipitation and streamflow over six years of monitoring. Two years of post-treatment data have documented significant reductions in P concentrations and loads from both treated watersheds. Reductions of approximately 20% in mean total P concentration and approximately 20-50% in mean total P load have been observed, with greater reductions occurring in the watershed receiving more extensive treatment. The effectiveness of riparian zone restoration in P reduction tended to be lower during periods of very high runoff, especially outside the growing season.

Agriculture↗
PubMedDate not supplied

[Results of elective open surgery for juxtarenal aortic aneurysms].

Review of the most significant surveys (data base: Pub Med on September 2003) of elective open surgery for Juxtarenal aneurysms and personal results of 106 cases (9.3% of AAA consecutively operated in the last 11 yrs.) are reported. Mortality and morbidity are discussed related to: technique of aortic cross-clamping; protective measures on splanchnic and renal perfusion; risks from previous CAD and chronic renal failure. Over all, the main predictive factor is the accuracy of the selected technique, without any difference among different approaches, and the same results of infrarenal aneurysms can be obtained.

Adult↗
PubMed2004

Vaccination against salmonella, enterohaemorrhagic E. coli and Campylobacter in food-producing animals.

The threat of zoonotic infection with food-poisoning enteric pathogens remains a major threat to public health throughout the world. Control of enteric pathogens within food-producing animals remains an obvious strategy to prevent the introduction of these pathogens into the human food chain. Vaccines are currently available for the control of Salmonella; however such vaccines vary in their efficacy and acceptability to the food production industries and consumers. Vaccines for the control of enterohaemorrhagic E. coli and Campylobacter are currently unavailable. Understanding the molecular basis of how these organisms colonise the intestines and cause disease is essential for the development of effective multivalent vaccines. The mechanisms by which these organisms colonise the gut will be reviewed. Bacterial Type Three Secretion Systems (TTSS) have been shown to be major virulence factors influencing the colonisation and pathogenicity of Salmonella and enterohaemorrhagic E. coli in some but not all animal species. Thus, understanding the specific nature of host/pathogen interactions is crucial in the development of cross-species vaccines. TTSSs act by delivering effector proteins into intestinal epithelial cells, which act to modify signalling events in host cells causing cytoskeletal and pathophysiological changes to the benefit of the pathogen. Disruption of TTSSs and/or related secreted effector proteins can be adopted as a strategy for the attenuation of live vaccine strains. Furthermore secreted effector proteins have the potential to be incorporated into sub-unit vaccines. As many of such effector proteins are conserved between different serotypes, such vaccines offer the hope of cross-serotype protective immune responses. Novel experimental vaccines are currently being developed to exploit these and other recent discoveries in bacterial virulence mechanisms. The potential of such vaccines to control zoonotic pathogens will be discussed.

Animals↗
PubMed1993

[Development of super-resistance to hypoxic hypoxia during adaptation to short-term stress].

Adaptation to intermittent short-term immobilization stress exposure increases the resistance of rats to hypoxic hypoxia. This was evidenced by the fact that in acute experiments in respiration with gas-mixture containing 6% of oxygen, the mortality of control rats was 65% compared with 10% of that of adapted rats. It has been estimated that this protective cross-effect of adaptation to stress is due to more stable and efficient mobilization of external respiration in adapted animals, and to a greater extent, to the fact that adapted rats tissues have gained a capacity of extracting more oxygen from hypoxemic blood compared to control animals. The role of previously stated phenomenon of adaptive stabilization of structures in superresistance to hypoxic hypoxia is discussed.

Adaptation, Physiological↗
PubMed1983

Characterization of in vivo cross-reactive tumor resistance between two cultured murine colon lines.

Previous comparative investigations of the in vivo biology of two cultured colon tumors of BALB/c origin, C-C26 and C-C36, demonstrated different biologic activities. To elucidate these differences, the immunogenicity of these lines in providing protection to a subsequent challenge with different doses of tumor cells was investigated. Furthermore, the specificity of this protection was evaluated with cross-protection experiments. The findings demonstrate these lines to be immunogenic and suggest the presence of cross-reactive tumor rejection type antigens on these two cultured colon tumor lines. BALB/c mice immunized with these tumors developed resistance to challenge with the same tumor as well as to challenge with the other colon tumor line. Unexpectedly, BALB/c mice immunized with C-C26 cells and challenged with a syngeneic methylcholanthrene-induced sarcoma, Meth A, exhibited partial resistance to this tumor compared to nonimmunized controls. However, mice immunized with C-C36 cells and challenged with Meth A cells supported the same rate of growth of this tumor as unimmunized controls. These results suggest the presence of at least two different cross-reactive tumor rejection antigens. The first antigen appears to be shared between C-C26 and C-C36 cells while the second antigen may be shared between C-C26 and Meth A. Further definition of these putative antigens could provide us with a better understanding for the diagnosis and treatment of colon tumors.

Animals↗