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Staphylococcus aureus is the most common causative agent of bovine mastitis and vaccines developed to control this disease showed limited protection due in part to the lack of common antigens among the mastitis isolates. We isolated and identified two genes encoding proteins with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity from a S. aureus strain isolated from bovine clinical mastitis. The GapB and GapC proteins share considerable homology to the GapB and GapC products of human strains of S. aureus. These two proteins could be distinguished by their different GAPDH activities and binding to bovine transferrin properties. Both gapB and gapC genes were conserved in 11 strains tested, and the GapC protein was present on the surface of all S. aureus strains.

Bacterial DNA contains a much higher frequency of CpG dinucleotides than are present in mammalian DNA. Furthermore, bacterial CpG dinucleotides are often not methylated. It is thought that these two features in combination with specific flanking bases constitute a CpG motif that is recognized as a "danger" signal by the innate immune system of mammals and therefore an immune response is induced when these motifs are encountered. These immunostimulatory activities of bacterial CpG DNA can also be achieved with synthetic CpG oligodeoxynucleotides (ODN). Recognition of CpG motifs by the innate immune system requires engagement of Toll-like receptor 9 (TLR-9), which induces cell signaling and subsequently triggers a pro-inflammatory cytokine response and a predominantly Th1-type immune response. CpG ODN-induced innate and adaptive immune responses can result in protection in various mouse models of disease. Based on these observations, clinical trials are currently underway in humans to evaluate CpG ODN therapies for cancer, allergy and infectious disease. However, potential applications for immunostimulatory CpG ODN in species of veterinary importance are just being explored. In this review, we will highlight what is presently known about the immunostimulatory effects of CpG ODN in domestic animals.

The gapC genes, encoding the cell surface-associated GapC proteins of S. uberis and S. agalactiae, have been cloned and sequenced. To identify potential vaccine candidates against S. uberis-induced bovine mastitis, lactating dairy cows were vaccinated with either (6 x His)GapC of S. uberis or S. dysgalactiae, or with a chimeric CAMP-factor antigen, CAMP-3. For 7 days following heterologous challenge with S. uberis, milk somatic cell counts were determined to assess differences in the severity of mastitis between vaccinates and an unvaccinated control group. Vaccination with S. uberis (6 x His)GapC or CAMP-3 resulted in a significant reduction in inflammation on several days post-challenge, most significantly for the former antigen. Inflammation was not reduced in S. dysgalactiae (6 x His)GapC vaccinates, suggesting that it does not confer cross-species protection.

[1] The ratio of sodium to potassium in the exosphere of Mercury is highly variable and averages about 100, considerably larger than for the Moon. We considered the possibility that this high value results from potassium loss rates that are larger than sodium loss rates. The principal loss processes are the sweeping of hot atoms off the planet by solar radiation acceleration and the capture of metal photoions by the solar wind. We found that radiation acceleration losses are not sufficiently different for sodium and potassium to explain the high ratio. Capture of sodium and potassium photoions by the solar wind is thought to be the major loss process. However, there is a competing process for the ions, which is collision with the surface, followed by neutralization. These atoms can return to the exosphere. The net steady state density of sodium and potassium in the exosphere depends on the relative efficiencies of solar wind capture and surface recycling. We propose that the photoion loss and recycling rates are sufficiently different for sodium and potassium to account for the high ratio. The higher mass of the potassium atom relative to sodium results in a smaller scale height and a larger gyroradius for potassium relative to sodium, which may result in more rapid net loss of potassium.

Themiggene ofStreptococcus dysgalactiae, a major bovine mastitis pathogen, encodes two plasma protein-binding receptors, α2-macroglobulin (α2-M) and immunoglobulin G (IgG). In this study, themiggene from oneS. dysgalactiaeisolate was cloned and expressed inEscherichia coli. The IgG receptor region encoded bymigwas conserved in 16S. dysgalactiaestrains. An isogenicmigmutant was constructed by allele replacement mutagenesis of the wild-type gene inS. dysgalactiae. The IgG-binding activity was lost in themigmutant strain, whereas the α2-M receptor activity was still expressed but was detected only in the culture supernatant. In flow cytometry phagocytosis and bacterial-colony-counting bactericidal assays, the wild-type strain was found to be significantly more resistant to phagocytosis and killing by bovine neutrophils (PMNs) than themigmutant strain when bacteria were preincubated with bovine serum. We therefore speculate that the Mig protein ofS. dysgalactiaeplays a role in virulence of the bacteria by binding to the plasma protein α2-M or IgG and thus preventing phagocytosis by bovine PMNs.

Cardiff University hosted the 14th annual logistics research network conference, from 9 to 11 September 2009. The conference represents the premier event provided by the Chartered Institute of Logi...

Global logistics management–sustainability, quality, risks, edited by W. Kersten, T. Blecker and H. Flamig, Erich Schmidt Verlag GmbH & Co, Germany, 2008, pp. ix & 482, 69.00 Euros (softcover), ISB...

Haemophilus somnus is able to survive and multiply in bovine blood monocytes (BBM) and alveolar macrophages (BAM), but the mechanisms used by H. somnus to evade killing mechanisms of bovine mononuclear phagocytes are not completely understood. To study the bactericidal ability of bovine mononuclear phagocytes following interaction with H. somnus , in vitro assay systems were developed to detect the luminol-dependent chemiluminescence response (LDCL) and nitric oxide (NO) production of BBM and BAM. Live logarithmically growing or stationary phase H. somnus inhibited the LDCL of BBM and BAM costimulated with opsonized Staphylococcus aureus . Inhibition of the LDCL response of BBM and BAM was not mediated by live H. somnus opsonized with hyperimmune serum, or by killed bacteria. H. somnus stimulated both BBM and BAM to produce NO at levels comparable with Escherichia coli lipopolysaccharide. While NO was being produced, viable H. somnus could still be isolated from the cell cultures. The ability of H. somnus to inhibit LDCL of both BBM and BAM, and resistance to NO killing may be an important mechanism that contributes to survival of the organism following ingestion by bovine mononuclear phagocytes.

The World Health Organisation considers vitamin A deficiency to be a public health problem in over 60 countries, putting at risk the lives and eyesight of an estimated 250 million preschool children.1 It is a major cause of morbidity and mortality2 and the single most important cause of blindness in children in developing countries,3 and it is entirely preventable. Our bodies need vitamin A for the maintenance of epithelial surfaces, for immune competence,4 for the normal functioning of the retina, and for growth, development, and reproduction. We obtain vitamin A from two sources: firstly, from fat soluble vitamin A present in milk, eggs, butter, and fish liver oils; secondly as provitamin A carotenoids in dark green leafy vegetables, red palm oil, and in red or orange coloured fruits and vegetables such as mango, papaya, sweet potato, and carrots. Most of the ingested retinol is absorbed in the small intestine and transported to the liver, where it is stored as retinyl palmitate. When required it is released into the blood stream in combination with retinol binding protein and is taken up by target cells throughout the body. When intake of vitamin A is inadequate to meet the body's …

The interactions between bovine mononuclear cells and Haemophilus somnus are known to be complex. To study this interaction, a flow cytometric assay was developed to assess the effect of H. somnus on phagocytosis of killed opsonized Staphylococcus aureus by bovine alveolar macrophages and blood monocytes. Using this in vitro system, it was found that log phase H. somnus significantly inhibited the phagocytosis of killed opsonized S. aureus by bovine alveolar macrophages obtained both from healthy calves and from cattle experimentally infected with H. somnus. However, killed log-phase H. somnus, in vitro passaged and stationary phase H. somnus had no effect on the phagocytic activity of these cells. In contrast to bovine alveolar macrophages, blood monocytes showed a significant increase in their phagocytic activity following in vitro exposure to either log or stationary phase H. somnus. Using a lypophilic, non-toxic fluorophore PKH2 to label live H. somnus, it was possible to simultaneously measure the uptake of both S. aureus and H. somnus. Stationary and log phase H. somnus were taken up by macrophages equally well, even though phagocytosis of S. aureus was inhibited by only log phase H. somnus. These results demonstrate the ability of H. somnus to modulate bovine mononuclear phagocytic function which might contribute towards the pathogenesis of bovine hemophilosis.

Objectives The objective was to determine the efficacy of coadministration of subcutaneous (SQ) insulin glargine in combination with intravenous (IV) insulin for treating diabetic ketoacidosis (DKA). Methods This was a prospective, randomized, controlled trial comparing coadministration of insulin glargine and IV insulin (experimental) with IV insulin (standard care control). The setting was emergency departments (EDs) in two hospitals in Houston, Texas. Patients presenting with blood sugar ≥ 200 mg/dL, pH ≤ 7.3, bicarbonate (HCO3) ≤ 18 mg/dL, ketonemia or ketonuria, and anion gap ≥ 16 between November 2012 and April 2013 were enrolled. All patients received IV insulin. Additionally, the experimental group was given SQ insulin glargine within 2 hours of diagnosis. Upon closure of anion gap, patients in the control group were subsequently transitioned to long-acting insulin. In the study group, IV insulin was discontinued and long-acting SQ insulin was reinstituted 24 hours after initial introduction. The primary outcome of time to closure of anion gap (TCAG) was compared between groups using a general linear model (GLM), adjusting for initial anion gap, etiology, and presence of comorbidities. Similarly, the secondary outcome hospital length of stay (LOS) was adjusted for age, etiology, and hospital site in the GLM. Rate of hypoglycemia and intensive care unit (ICU) admission was compared using Fisher's exact test while ICU LOS was compared using Wilcoxon's two-sample test. Results A total of 40 patients were enrolled in this pilot trial. The estimated mean TCAG was 10.2 hours (SE ± 6.8 hours) in the experimental group and 11.6 hours (SE ± 6.4 hours) in the control group (p = 0.63). The estimated mean hospital LOS was 3.9 days (SE ± 3.4 days) in the experimental group and 4.8 days (SE ± 3.6 days) in the control group (p = 0.66). Incidents of hypoglycemia, rates of ICU admission, and ICU LOS were similar between the groups. Conclusions Coadministration of glargine in combination with an insulin infusion in the acute management of DKA is feasible. Further study is needed to determine the true efficacy in terms of TCAG and hospital LOS.

Thirty-nine Escherichia coli isolates from broiler chickens with cellulitis were serotyped and analyzed for clonal relationships by multilocus enzyme electrophoresis. The isolates were further characterized with respect to hemagglutination (HA); serum resistance; antibiotic susceptibility; production of aerobactin, colicin V, and hemolysin; expression of K1 or K5 capsule; sensitivity to cloacin DF13 after treatment with diphenylamine; expression of iron-regulated outer membrane proteins; and virulence in 1-day-old chickens. In addition, the isolates were examined for the presence of DNA sequences related to F1A (fim) and P (pap) fimbriae, aerobactin synthesis (iuc) and transport (iut), hemolysin operon hly, and TraT lipoprotein-induced serum resistance (traT). Only 38.4% of the isolates were typeable with standard O antisera, and of these, serogroups O25 and O78 were the most frequently observed. Multilocus enzyme electrophoresis, based on 20 enzymes, resolved 17 electrophoretic types, forming seven clusters. Isolates from four of these clusters fell into E. coli clone complexes that have been previously reported to be commonly associated with avian colibacillosis. All isolates expressed two to five iron-regulated outer membrane proteins, were resistant to serum and cloacin DF13, and possessed DNA sequences homologous to fim and iuc/iut. Most isolates (72%) were positive for traT, and a majority produced colicin V and aerobactin (92 and 82%, respectively). Assays for the presence of fim and pap DNA sequences, for HA, and for virulence gave variable results but suggest that cellulitis isolates may express F1A and/or other mannose-resistant HA fimbriae different from P and may be virulent in 1-day-old chickens. Our results support the hypothesis that cellulitis in broilers in many cases is caused by E. coli clones identical to other pathogenic avian E. coli strains. Certain clones may be specific to cellulitis, because 25% of the isolates tested belong to clusters not related to known clone complexes.

The gene coding for the CAMP factor from a strain of Streptococcus uberis (ATCC 9927) was cloned in Escherichia coli. Chromosomal DNA from Streptococcus uberis was used to construct a gene library in plasmid pTZ18R and six CAMP-reaction positive clones were obtained from a total of 10,000 transformants. One clone, pJLD21, was subcloned and the CAMP factor gene was located in a 3.2 kb BamHI fragment. The nucleotide sequence of Streptococcus uberis CAMP factor gene was determined and the deduced amino acid sequence is highly homologous to the corresponding Streptococcus agalactiae protein. Immunoblot analysis revealed that the recombinant strain pJLD21 expressed a protein with a molecular weight of 28 000. Antibodies raised against purified Streptococcus uberis CAMP factor cross-reacted with Streptococcus agalactiae protein B.

Many properties have been associated with Pasteurella haemolytica leukotoxin and other repeat-in-toxin toxins, including their cytotoxic activity on various cells of the lymphoid and nonlymphoid systems as well as their ability to modulate the immunological activity of lymphocytes and monocytes. In this study, we assessed the ability of P. haemolytica leukotoxin to affect the expression major histocompatibility complex (MHC) class II molecules on bovine peripheral monocytes. Peripheral blood mononuclear cells were isolated from P. haemolytica leukotoxin-seronegative calves and incubated with various concentrations of authentic leukotoxin as well as the recombinant lktA gene product (LktA). Expression of MHC class II antigen on cells was evaluated by flow cytometric methods. The results indicated that both a crude, authentic leukotoxin preparation and LktA were able to affect MHC class II expression by inducing a marked downregulation of MHC class II expression on bovine monocytes. However, when cells were activated with gamma interferon (IFN-gamma), LktA and Lkt had little or no detectable effect. By using a cell line which expresses MHC class II only after activation by INF-gamma, we were able to confirm the observation that LktA had no effect on the expression of MHC class II after IFN-gamma treatment. Leukotoxin affected the functional capacity of monocytes to present antigen, as demonstrated by the ability of LktA or authentic leukotoxin to totally inhibit a mixed lymphocyte culture from MHC-mismatched calves. Thus, leukotoxin was able to downregulate constitutive expression of MHC class II expression, and we propose that this is a novel way in which this molecule can affect the immune function of monocytes, playing an important role in bacterial pathogenesis and survival of organisms at the infection site.

In order to better identify the role of the Salmonella pathogenicity island 2 (SPI-2) type III secretion system (T3SS) in chickens, we used the well-known gentamicin protection assay with activated HD11 cells. HD11 cells are a macrophage-like chicken cell line that can be stimulated with phorbol 12-myristate 13-acetate (PMA) to exhibit more macrophage-like morphology and greater production of reactive oxygen species (ROS). Activated HD11 cells were infected with a wild-type Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium) strain, a SPI-2 mutant S. Typhimurium strain, a wild-type Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) strain, a SPI-2 mutant S. Enteritidis strain, or a non-pathogenic Escherichia coli (E. coli) strain. SPI-2 mutant strains were found to survive as well as their parent strain at all time points post-uptake (PU) by the HD11 cells, up to 24 h PU, while the E. coli strain was no longer recoverable by 3 h PU. We can conclude from these observations that the SPI-2 T3SS of S. Typhimurium and S. Enteritidis is not important for survival of Salmonella in the activated macrophage-like HD11 cell line, and that Salmonella must employ other mechanisms for survival in this environment, as E. coli is effectively eliminated.

Theoretical analyses of the orbital debris environment have shown that collisions could eventually become the dominant source of orbital debris. Debris will be added to the environment more rapidly by collisions than it can be removed by atmospheric drag. The models suggest that this process has already begun in some altitude regimes, specifically in the region from about 900 to 1000 km. It is important to verify these predictions by measurement in order to provide solid justification for early preventive measures. Collisions of two large objects are predicted to be very infrequent at the present time. However, the models predict that collisions of small debris with large objects will take place at an appreciable rate. One collision of an 0.5 cm object with a large object is expected each year. The collision rate increases with decreasing size, such that 80 collisions of 1 mm objects with a large object are expected each year. These collisions will not destroy the large object, but will generate a shower of microdebris. The particles generated by such collisions are mostly thrown forward, and either escape, or enter exceptionally long-lived elliptical orbits. It is suggested that an orbital experiment be flown for the specific purpose of detecting the predicted collisions by measuring the micro-debris fluxes resulting from the collisions.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Flexibility is an issue widely studied in the manufacturing literature, but only recently has attention been paid to flexibility in logistics and supply chain management. Flexibility is taking prominence due to the uncertainties and disruptions created in the production and distribution processes of an organisation and its respective supply chains. This paper aims at studying the level of transport flexibility achieved in the ocean transportation industry to gain understanding on the strategic choices of carriers to cope with market changes and customer demand. Our analysis indicates the different strategic choices ocean transportation companies need to make with regards to transport flexibility.

The interactions between bovine polymorphonuclear leukocytes (PMNs) and the bacterium Haemophilus somnus are known to be complex. In this paper, we evaluated the effect of H. somnus on PMN function using a flow cytometric (FC) technique that simultaneously determined the extent of phagocytosis and hydrogen peroxide production by PMNs, as well as using conventional techniques, such as the nitroblue tetrazolium (NBT) and chemiluminescence assays, to analyse the PMN respiratory burst. Results from the FC and chemiluminescence assays demonstrated that in vitro exposure of PMNs to logarithmically growing H. somnus reduced the respiratory burst of PMNs obtained from healthy calves. However, this reduction was not detected by the NBT assay. A decrease in phagocytosis by PMNs could also be shown using the FC assay. In addition, PMNs from calves with acute Hemophilosis (i.e. exposed to H. somnus in vivo) showed reduced activity when compared to PMNs from healthy calves. These in vitro and in vivo observations indicate that the modulation of bovine PMN function by H. somnus may contribute significantly towards the pathogenesis of the disease.

Oligodeoxynucleotides (ODN) containing cytosine-phosphodiester-guanine (CpG-ODN) motifs have been shown to stimulate the innate immune system against a variety of bacterial and protozoan infections in a variety of vertebrate species. The objective of this study was to investigate the immunostimulatory effect of CpG-ODN in neonatal broilers against Salmonella Typhimurium septicemia. Day-old broiler chicks, or embryonated eggs that had been incubated for 18 days, received 50 microg of CpG-ODN, 50 microg of non-CpG-ODN, or saline. Four days after exposure to CpG-ODN or day 2 posthatch, 1 x 10(6) or 1 x 10(7) colony-forming units (cfu) of a virulent isolate of Salmonella Typhimurium was inoculated by the subcutaneous route in the neck. Clinical signs, pathology, bacterial isolations from the air sacs, and mortality were observed for 10 days following challenge with Salmonella Typhimurium. The survival rate of birds in groups receiving either non-CpG-ODN or saline following Salmonella Typhimurium infection was 40%-45%. In contrast, birds receiving CpG-ODN had significantly higher survival rate of 80%-85% (P0.0001). Bacterial loads and pathology were low in groups treated with CpG-ODN compared to the groups receiving saline or non-CpG-ODN. Colony-forming units of Salmonella Typhimurium in the peripheral blood were significantly lower in birds treated with CpG-ODN compared to the group that received saline. This is the first time that CpG-ODN has been demonstrated to have an immunoprotective effect against an intracellular bacterial infection in neonatal broiler chickens following in ovo delivery.

Background Streptococcus pneumoniae infection starts from colonization of the host respiratory tract where interaction with host respiratory tract epithelial cells occurs. To investigate pneumococcal genes that are involved in the early stage of interaction with host epithelial cells, transcriptional responses of an encapsulated pathogenic pneumococcal strain TIGR4 upon exposure to human lung epithelial cells A549 for 0.5 h and 1 h time periods were investigated by using TIGR (JCVI) microarray technology. Gene expression changes were validated by quantitative real-time PCR (qRT-PCR) analysis. Findings We observed different transcriptional profiles at two incubation time periods in which most gene expressions were down-regulated at 0.5 h but up-regulated at 1 h. Many genes associated with ribonucleotide biosynthesis were down-regulated at both time points, whereas the genes associated with cell envelope, energy metabolism, transport and protein synthesis were mostly up-regulated at 1 h. Furthermore, these profiles were compared to the transcriptomes of a TIGR4-derived strain in response to human macrophages for the same time periods. We found one set of genes that exhibited similar expression changes upon exposure to both types of host cells, including cell envelope-associated bgaA (SP0648) and nanA (SP1693), and uncharacterized gene clusters such as SP1677–SP1680 and SP1688–SP1690. Conclusion These data indicate that at the early stage of interaction with host epithelial cells, a complex gene regulation and expression change occur in bacteria. Some of them might play an essential role during pathogen-host interactions and for the establishment of infection.

Imagine the scenario. You are an indigenous teacher or civil servant stationed in a small rural community in a tropical country. Almost by definition you are over the age of 40 as your government has not recruited any public employees for several years on the advice of the World Bank and International Monetary Fund. You are a worried man. Your second daughter, always the intelligent one among your children, has begun to perform poorly in school. Her teacher says she makes too many mistakes when copying her lessons from the blackboard. Your wife is also distraught. Her mother, who recently underwent a cataract operation at great expense (your own), does not see well enough to return to her village. And worse, your own eyes seem to be failing and you can no longer study in the evenings for that professional diploma that would bring a promotion at work. Your distress is heightened by the knowledge that even if you travelled the 350 miles to the capital during your annual holiday the waiting list to see the ophthalmologist is over four months long and the price of the three pairs of glasses at the optician's shop well beyond …

The preparation of two stable azetidine N-oxides is described; one structure was confirmed by X-ray crystallography and the second was found to undergo a quantitative ring expansion to yield a new 6-hydroxy tetrahydro-1,2-oxazine, a potentially useful reagent for further synthetic transformations.

The preparation of a number of piperazine derivatives bearing amino acid substituents on the nitrogen is described; these compounds undergo oxidation with MCPBA to yield bis(N-oxides) in which both oxygen atoms are axially orientated and hydrogen bonded to the amide NHs, giving highly defined conformations to the molecules; the structure of the valine derivative (8c) was confirmed by X-ray analysis.

The novel pyrrolobenzodiazocine (1) has been prepared by an intramolecular Staudinger/aza Wittig protocol from the precursor azido aldehyde (2) in a remarkable 93% yield. Aldehyde (2) was prepared by coupling protected homoprolinol with 2-azidobenzoic acid followed by deprotection and oxidation.

It is not often that I receive an invitation to attend an international conference. We who labour in the remote outposts of poor countries are hardly top of the list of likely candidates for such meetings. And, let me be honest, it is not a personalised invitation as such, but only a brochure sent out to a wide constituency of those who might have an interest in eliminating vitamin A deficiency. It is addressed to “Dear colleague” and says, “It is our pleasure to invite you, we look forward to your participation …and know that your attendance will add to its success.” I read on. The meeting is sponsored by the International Vitamin A Consultative Group (IVACG), which is dedicated to reducing the prevalence of vitamin A deficiency worldwide. IVACG hopes to promote research and awareness of the problem of vitamin A deficiency by means of such international meetings and to encourage innovative action. Aside from the formal lectures and scientific presentations, the meeting will afford …

Editor,—The prevalence of blindness in Africa, both for adults and children, is the highest in the world.1 Cataract accounts for over half of this blindness and a large part of the remainder (trachoma, xerophthalmia, onchocerciasis, glaucoma) is preventable.2 There is on average one ophthalmologist per million population in Africa today. Most of these specialists are practising in the capital cities and large conurbations.3 Yet a majority of the population still resides in rural areas gaining a livelihood from subsistence farming. Access to affordable eye care for most people is therefore severely limited. In English speaking Africa the penury of ophthalmic nurses and doctors is being tackled realistically with diploma and fellowship training courses available in west, east, and southern Africa. But the 19 French speaking countries south of the Sahara lag far behind, with only a few teaching centres that are incapable of meeting the shortfall of trained eye workers and whose expertise is largely unadapted to the realities of the region. Up to a third of all ophthalmologists in francophone Africa perform no surgery at all and those who do perform, on average, only 160 cataract operations each …

Illness is a pain in the neck. Its arrival is always unwelcome, unsolicited, and an intrusion on the more pressing urgency of living. Only the most perverse individual could relish the experience. All the more inconvenient then when you are far from home. “Not much of you, is there?” joked the avuncular physician as he cast an eye over my unclothed form on the examination couch. I had flown into London that morning, evacuated from west Africa, for investigations into marked loss of weight and a sky high sedimentation rate. The dark spectre of tuberculosis, AIDS, or metastatic malignancy loomed and I saw it reflected in the worried facial expressions of those about me. I, too, was naturally scared, for it could mark the end not only of my chosen career in the tropics but of my very life, neither of which I cared to countenance. True, I had not been well for the previous three months and, although I had continued with a very full schedule of work, I had stopped running …

Experimental reproduction of avian cellulitis was conducted by subcutaneous inoculation of 25-day-old broiler chickens with a field isolate of serogroup O78 Escherichia coli. Development of the cellulitis lesion occurred as early as 24 h post-infection. Reproduction of cellulitis occurred in 98% of inoculated birds, and E. coli was isolated from > 75% of cellulitis lesions. In addition to cellulitis, other lesions, including pericarditis, airsacculitis, osteomyelitis, arthritis, and perihepatitis, occurred in > 80% of birds inoculated with E. coli. Bacteremia occurred as early as 6 h post-infection and dramatically declined by 5 days post-infection. Seventeen of 59 (29%) birds inoculated with E. coli developed a fatal infection between 1 and 6 days post-infection, and bacteria were isolated from lesions in 98% birds. In contrast, E. coli was not isolated from lesions in birds that survived until days 7-14 post-infection. Birds that survived with cellulitis and other lesions until day 14 post-infection had a significantly lower body weight compared with the control group. This avian model of cellulitis and other lesions will be useful for studying the development of vaccination strategies for E. coli in broilers.

The outer-membrane protein (OMP) profile of Pasteurella haemolytica grown under iron-replete and iron-restricted conditions was studied by polyacrylamide gel electrophoresis and immunoblotting. A serotype 1 isolate induced the synthesis of a new 77,000 Mr OMP in iron-restricted media while two other proteins of 100,000 Mr and 71,000 Mr were synthesized in increased amounts. None of these proteins were peptidoglycan-associated or heat-modifiable, and only the 100,000 Mr protein showed some degree of disulphide cross-linking. Kinetic analysis revealed that the iron-repressible proteins appeared in the outer membrane within 15 min of establishment of iron-restricted conditions. Analysis of P. haemolytica isolates representing serotypes 1 to 12 showed that iron-repressible OMPs of 77,000 Mr and 71,000 Mr could be induced in all 12 serotypes but that there was some variability in the expression of the 100,000 Mr protein. Immunoblotting of OMPs with convalescent sera from P. haemolytica-infected calves indicated that antibodies directed against all three iron-repressible OMPs were present, suggesting that these proteins were expressed in vivo.

A problem of considerable interest in orbital debris research is the determination of the cause of the fragmentation of a satellite from the observed radar cross section and orbital element data. In this paper, analytic representations of the observed distribution functions of the radar cross section and the orbital plane change angle are derived. This then allows for the extraction of a small number of features that describe the observed data. Based on the known cause of fragmentation of a subset of satellites, a linear classifier is trained on these derived features. The discriminant function derived from this training is used to determine the previously unknown cause of the satellite breakup. the technique developed is objective and has been applied to the study of the cause of a number of unknown satellite breakup events.

The outer membrane protein profile of Actinobacillus (Haemophilus) pleuropneumoniae grown under iron-restricted and iron-replete conditions was studied by polyacrylamide gel electrophoresis and immunoblotting. A virulent serotype 1 isolate synthesized a novel protein with an apparent molecular weight of 105,000 (105K) and increased the synthesis of a 76K protein under iron-restricted conditions. Both proteins were synthesized within 15 min of establishment of iron-restricted conditions. Proteins of equivalent molecular weights could also be induced by iron restriction in serotype 2, 3, 4, 5, and 7 isolates of A. pleuropneumoniae. Convalescent-phase sera from serotype 1-infected pigs contained antibodies which recognized both the 105K and 76K proteins from all six serotypes examined, indicating that these proteins were expressed in vivo and were immunologically conserved. Cells expressing the 105K and 76K proteins also displayed an enhanced ability to bind Congo red and hemin, suggesting that one or both of these proteins functioned to acquire complexed iron during in vivo growth.

Spectral data are reported from a search for potassium in the Mercury atmosphere. The data were collected with instrumentation at Kitt Peak (7699 A) and at McDonald Observatory (7698.98 and 7664.86 A). The equivalent mean widths of the potassium emission lines observed are tabulated, along with the estimated abundances, which are compared with sodium abundances as determined by resonance lines. The average column abundance of potassium is projected to be 1 billion atoms/sq cm, about 1 percent the column abundance of sodium.

Sodium emission has been observed up to 1200 km above the subsolar limb of the moon at third quarter. The intensity of the emission is far in excess of that predicted from the scale height and surface density derived previously from measurements of sodium emission at low altitudes above the lunar surface. This can be explained by assuming that there are both 'hot' and 'cold' components of the lunar sodium exosphere.

Mutants of Pseudomonas aeruginosa strain 1 which incorporate relatively large amounts of thymine into their DNA were isolated. Three steps were required to produce this phenotype. First, strains constitutive for thymine uptake and catabolism were isolated, followed by selection for mutants which could not catabolize thymine. The double mutant was then used to isolate a strain exhibiting greater sensitivity to the thymine analog 5-bromouracil. Efficient DNA-specific pulse labelling with isotopic thymine was successfully carried out with this strain.

A rapid method for the extraction and purification of DNA from human leukocytes was developed. Crude nucleic acids were obtained by sodium docdecylsulfate (SDS) lysis and potassium acetate precipitation of other cellular material, and the DNA was purified by ribonuclease digestion, diethylaminoethyl (DEAE) cellulose chromatography and ethanol precipitation. DNA obtained by this method is biologically active as reflected by its ability to act as substrate for various nucleases and T4 DNA ligase. The yield was sufficiently high that DNA from less than 1 ml of blood could be used for a number of reactions.

Space lifetime of possible parent molecules of radicals in comets estimated from absorption cross sections and solar uv flux

A mass-spectrometric stirred-reactor technique was used to study the reaction of atomic oxygen with methane with low concentrations of molecular oxygen. An overall rate constant for oxygen-atom disappearance due to added methane was obtained for the temperature range 375 to 576°K. This rate constant was 4 × 1014 exp (− 10 000/RT) cm3 mole−1 s−1 and was compared with a previous rate constant for this reaction that had been measured in the presence of a large excess of molecular oxygen. This comparison showed that the presence of an excess of molecular oxygen produced a considerable increase in oxygen-atom consumption at low temperatures, but only a small increase at high temperatures. From product analyses, the stoichiometry of the reaction could be approximately represented by [Formula: see text]From the reaction stoichiometry and the rate constant for the oxygen-atom disappearance, the rate constant for methane disappearance was calculated to be 1 × 1014 exp (− 10 000/RT) cm3 mole−1 s−1. The presence of excess molecular oxygen has very little effect on this rate constant, contrary to the result found for the disappearance of atomic oxygen.

Comparison of observed and calculated altitude distributions for the sodium airglow indicates that airglow processes involving combined sodium cannot account for the observations. It is suggested that the airglow results from collisions of neutral atomic sodium with vibrationally excited oxygen. This process can account for the observed altitude distribution and, possibly, the total intensity of the sodium airglow.

Larger‐than‐bandgap photovoltages were observed in thin films of CdS which had high resistances and were not uniformly thick. The decay of the photovoltage after removal of light and the effects of temperature and light intensity on the photovoltage were studied and compared to a theoretical model. The results conform with the concept that the photovoltage is due to a space charge produced by a nonuniform distribution of trapped carriers in a multitude of series‐connected elements. Analysis of the decay of the photovoltage showed the presence of at least four trapping levels at 0.08, 0.14, 0.26, and 0.41 eV.

We investigated the efficacy of a novel microparticle (MP) based vaccine formulation consisting of pertussis toxoid (PTd), polyphosphazene (PCEP), CpG ODN 10101 and synthetic cationic innate defense regulator peptide 1002 (IDR) against Bordetella pertussis in mice. We studied whether encapsulation of these IDR-CpG ODN complexes into polyphosphazene-based microparticles further enhanced their immunomodulatory activity compared to soluble formulations containing PCEP (SOL), or without PCEP (AQ). In vitro stimulation of murine macrophages showed MP induced significantly higher levels of pro-inflammatory cytokines. When assessed in a B. pertussis infection challenge model, a single immunization with MP formulation led to significantly lower bacterial loads compared to other formulations and non-vaccinated animals. ELISPOT of splenocytes showed that MP group mice had significantly higher number of antigen-specific IL-17 secreting cells. The cytokine profile in lung homogenates of MP group mice after challenge showed significantly higher amounts of MCP-1, TNF-α, IFN-γ, IL-12 and IL-17 and significantly lowered IL-10 levels suggesting a strong Th1 shift. Protection was observed against challenge infection with B. pertussis. On the other hand protective immune responses elicited in Quadracel® immunized mice were Th2 skewed. Hence, we conclude that formulation of PTd, PCEP, CpG ODN and IDR into MP generates a protective immune response in mice against pertussis emphasizing the potential of MP as a delivery vehicle for the potential development of single-shot vaccines.

The spectrum of Mercury at the Fraunhofer sodium D lines shows strong emission features that are attributed to resonant scattering of sunlight from sodium vapor in the atmosphere of the planet. The total column abundance of sodium was estimated to be 8.1 x 10(11) atoms per square centimeter, which corresponds to a surface density at the subsolar point of about 1.5 x 10(5) atoms per cubic centimeter. The most abundant atmospheric species found by the Mariner 10 mission to Mercury was helium, with a surface density of 4.5 x 10(3) atoms per cubic centimeter. It now appears that sodium vapor is a major constituent of Mercury's atmosphere.

A 10-year review of procedures undertaken in the operating theatres of a rural mission hospital in West Africa showed a total of 13819 procedures. Of these, one-third were general surgical, one-third were minor procedures, and one-third were obstetric, gynaecological or orthopaedic. This review is a record of the surgical procedures undertaken in a "typical" rural hospital in the Third World. It also indicates that a doctor contemplating a period of overseas service in such a hospital should have basic training in general surgery, obstetrics, gynaecology and trauma.