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The requirements for improved fuel economy and reduced vehicle emission have driven the lubricant industry to develop new lubricants for engines and other dynamic systems. The selection of appropriate lubricant formulation is a complicated process involving extensive and costly bench and field tests. Thus, there is a demand for developing quick, effective and less costly methods to evaluate and rank lubricants. The authors previously proposed a statistical technique for evaluating and ranking lubricants through examining spatial variations in local mechanical properties of a worn surface after lubricated sliding testing using a micromechanical probe. Examination of the mechanical heterogeneity of worn surface has been turned out a promising approach for prescreening lubricants before further bench and field tests. Research was conducted to further investigate the suitability of such a method to evaluate lubricant performance during lubricated wear tests for a number of engineering materials and in particular, to identify which mechanical property (e.g. hardness, Young's modulus, creep behaviour) was the most sensitive and reliable indicator of the surface mechanical heterogeneity. Efforts were also made to identify the optimum indentation load range for evaluating the mechanical heterogeneity. It was demonstrated that the statistical method based on the heterogeneity of worn surfaces was effective for evaluating and ranking lubricants. Microhardness was proven to be the most suitable parameter for evaluation of the mechanical heterogeneity of worn surfaces, especially for harder materials.

A generalized methodology to analyse lattice-rod scans from helium atom scattering (HAS) has been developed, allowing in situ measurement of interlayer spacing during thin film growth. A Lomb periodogram technique is used to analyse the interference fringes observed in a lattice-rod scan of a stepped crystal surface. The algorithm is ideally suited to the small, unevenly sampled HAS data sets typically collected and has the advantage that the significance of peaks in the resulting frequency distribution can be calculated. We show how the method can be used to assess the significance of each interlayer spacing quantitatively. Using the growth of cobalt on copper(111) as an example, the statistical significance of the surface step height distribution is calculated directly. This paper represents a considerable improvement over existing fast Fourier transform-based methodologies.

Hind III and Bam HI restriction endonuclease digests of genomic DNA of 25 Bacteroides fragilis strains, isolated from faeces, intestinal mucosa and infections were investigated. DNA analysis of single isolates from 10 patients with a B.fragilis infection revealed 10 different DNA profiles. DNA isolated from all 15 strains from faeces and intestinal mucosa of one patient showed identical patterns, confirming occurrence of one dominant strain in an individual. Restriction endonuclease DNA analysis provides a sensitive and useful technique for the typing of B.fragilis in epidemiological studies.

Differences in nephropathogenicity between Escherichia coli strains were studied by following the kinetics of the viable count in the mouse kidney during 8 h after intravenous injection. Assuming as a reference point that at zero time 0.1% of the inoculum was lodged in the kidney, we found that strains fell into three main groups with different behavior patterns: in group I, the viable count fell and remained low; in group II, the viable count first fell and then rose after 4 h, reaching the level of the reference point within 8 h; in group III, the viable count rose rapidly and remained high. The kinetics of the viable counts were also studied in blood, spleen, and liver: group I and II strains behaved similarly; only in the kidney did group II strains show higher counts than group I strains. These data suggest that group II strains are specifically virulent for the mouse kidney. Group III strains also gave higher viable counts in blood and spleen but comparable counts in the liver, suggesting that group III strains are more generally virulent. Fifty percent lethal dose measurements confirmed the conclusion that group I strains are avirulent and group III strains are the most virulent. Possible relationships between behavior pattern and serotype are discussed.

Under conditions of iron starvation, Bacteroides fragilis expresses various iron-repressible outer membrane proteins (IROMPs). A 44-kDa protein appears to be one of the major outer membrane proteins (OMPs) in B. fragilis under iron stress and plays a role in heme uptake by this bacterium. To determine whether the 44-kDa IROMP of B. fragilis is expressed in vivo and whether this protein is immunogenic, we used Western immunoblotting to examine serum samples from patients with an infection caused by Bacteroides species. All the serum samples from patients and from normal controls showed reactivity with several proteins of B. fragilis. Only serum samples from patients infected with B. fragilis showed immunoreactivity with the 44-kDa protein. We also used a rat infection model to study the immune response against this protein during the process of an intra-abdominal infection in these animals. During the first 8 days of infection a gradual increase of antibodies to the 44-kDa protein in the rat was detected. These results suggest that the 44-kDa IROMP is expressed in vivo, since it induces an antibody response in patients and animals. We also analyzed 85 strains of the B. fragilis group for the presence of proteins antigenically related to the B. fragilis 44-kDa protein. The data indicate that this protein was conserved in B. fragilis strains and was absent in the other bacterial strains tested.

The role of hemolysin in the nephropathogenicity of Escherichia coli was studied in a hematogenous pyelonephritis model in mice. The nephropathogenicity of a nonhemolytic, avirulent E. coli strain was increased by simultaneous injection with its hemolytic, nephropathogenic parent. This helper mechanism could be attributed to hemolysin, since the simultaneous injection of partially purified hemolysin gave a similar enhancement of nephropathogenicity. Intraperitoneal injection of hemoglobin or iron sulfate before intravenous challenge with this avirulent strain also led to increased virulence. The nephropathogenicity-enhancing effect of hemolysin is therefore supposed to depend on increasing the level of available iron in the host. Under conditions of plentiful iron, hemolysin production was repressed, as shown by in vitro growth experiments in the presence of exogenous iron. These results suggest that the production of hemolysin is regulated by feedback inhibition.

The nephropathogenic Escherichia coli strain P673 was shown to harbor two plasmids with molecular sizes of 70 and 41 megadaltons, respectively. The 70-megadalton plasmid, pCW1, coded for tetracycline resistance, whereas hemolysin production was coded by the 41-megadalton plasmid, pCW2. Plasmid pCW1 proved to be self-transmissible, in contrast to pCW2. Transfer of the hemolysin character was associated with the appearance of a 110-megadalton plasmid, pCW3. The incompatibility of pCW3 with both native plasmids and restriction enzyme analysis led to the conclusion that pCW3 is a cointegrate of pCW1 and pCW2, pCW2, carrying the hemolytic determinant, is involved in the nephropathogenic character of strain P673, because (i) elimination of pCW2 from P673 was associated with a loss of virulence and (ii) the nephropathogenicity of the avirulent mutant could be restored by reintroduction of pCW2 DNA as part of a cointegrate structure.

To investigate the repeatability of continual assessment of the gastric emptying rates of carbohydrate solutions in exercising subjects using 99mtechnetium labelling.

E. coli strains were isolated from urine specimens of hospitalised patients with acute pyelonephritis, acute cystitis or asymptomatic bacteriuria (ABU), and tested for virulence in an experimental mouse model. Of 12 pyelonephritisstrains 11 were shown to be virulent and 1 avirulent; of 12 cystitis-strains 4 were virulent and 8 avirulent; of 12 ABU-strains 5 were virulent and 7 avirulent. It is concluded that, while no difference in virulence was found between cystitis-and ABU-strains, pyelonephritis-strains were more often virulent than cystitis-and ABU-strains.

The low concentration of free iron in body fluids creates bacteriostatic conditions for many microorganisms and is therefore an important defense factor of the body against invading bacteria. Pathogenic bacteria have developed several mechanisms for acquiring iron from the host. Siderophore-mediated iron uptake involves the synthesis of low molecular weight iron chelators called siderophores which compete with the host iron-binding glycoproteins lactoferrin (LF) and transferrin (TF) for iron. Other ways to induce iron uptake, without the mediation of siderophores, are the possession of outer membrane protein receptors that actually recognize the complex of TF or LF with iron, resulting in the internalization of this metal, and the use of heme-compounds released into the circulation after lysis of erythrocytes. In this review, the nonsiderophore-mediated iron-uptake systems used by certain pathogenic bacteria are emphasized. The possible contribution of these iron-uptake systems to the virulence of pathogens is also discussed.

Biomechanics: principles and applications. Rik Huiskes et al. (eds), Martinus Nijhoff, The Hague, 1982, xi + 458 pp, $65 (hb), ISBN 90 247 3047 3Exercise physiology: energy, nutrition and human performance. William D. McArdle, Frank I. Katch and Victor L. Katch, Lea & Febiger, Philadelphia, 1981, xi + 508 pp, $25.25, ISBN 0 8121 0682 2Gymnastics: a mechanical understanding. Tony Smith, Hodder and Stoughton, London, 1982, xv+175 pp, £4.95 (pb), ISBN 0 340 28165 0The musculoskeletal manual. J. S. Birnbaum, Academic Press, London, 1982, ix+ 377 pp, £13.20 (pb), ISBN 0 12 788075 1Exercise, science and fitness. E. J. Burke (ed.), Mouvement, New York, 1982, 260 pp, £7.50 (pb), ISBN 0 932 392The mental aspects of gymnastics. Lars-Eric Uneståhl, Veje Förlag, Orebro, Sweden, 1983, 156 pp, $9.95 (pb), ISBN 91 85810 04 5Social science of play, games and sport: learning experiences. G. C. Roberts et al., Human Kinetics, Champaign, Illinois, 1979, 104 pp, £8.95 (pb), ISBN 0 931250 13 7

Get fit for badminton: A practical guide to training for players and coachesJ. Downey and D. Brodie, Pelham Books, London, 1980 127 pp, £4.95 (hb), ISSN 0 7207 12335Strength fitness: Physiological principles and training techniquesWayne L. Westcott, Allyn and Bacon, Boston, 1982 xi + 192 pp + appendices, £6.95A bibliography of research papers on physique, somatotyping and body composition related to sports performancePeter Bale, Brighton Polytechnic, Eastbourne, 1981 31 ppPerspectives on the academic discipline of physical educationGeorge A. Brooks (ed.), Human Kinetics Publishers, Champaign, Illinois, 1981 (sole UK distributors: Eddington Hook & Co., Tonbridge, Kent) 398 pp, £12.50The running shoe bookPeter R. Cavanagh, Anderson World Inc., California, 1980 viii + 390 pp, 237 Illustrations, £8.65

Possession of specialized iron acquisition systems is a prerequisite for the survival of pathogenic bacteria in their host. The purpose of this study was to determine whether Bacteroides fragilis, a clinically important Gram-negative anaerobic bacterium, possesses a specific haem-uptake system. Growth studies indicated that this microorganism can utilize haem from either haemoglobin or haptoglobin-haemoglobin as its sole source of iron. Iron-repressible haem-binding protein complexes (HBP complexes), involved in the uptake of haem from haptoglobin-haemoglobin were detected by means of lithium dodecyl sulfate polyacrylamide gel electrophoresis (LDS-PAGE). Four polypeptides of approximately 60, 58, 49 and 35 kDa, which are part of these HBP complexes, were identified as haem-binding proteins. A 44 kDa iron-repressible outer-membrane protein is needed for a functional HBP complex, but the exact role of this protein in the uptake of haem is still unknown. Copyright 1994, 1999 Academic Press

A monoclonal antibody (MAb) raised against Salmonella minnesota R595 and specific for alpha-3-deoxy-D-manno-octulosonic acid (alpha-Kdo) of the inner core was tested for binding to lipopolysaccharides (LPS) of Klebsiella pneumoniae. The MAb was tested in several assay systems (enzyme-linked immunosorbent assay, passive hemolysis, and inhibition of passive hemolysis) with a large panel (n = 23) of K. pneumoniae LPS representing all nine currently known O serotypes. MAb 20 showed reactivity with almost all O serotypes of K. pneumoniae LPS, and this reactivity could be inhibited by synthetic Kdo. This suggests an epitope in the cores of these Klebsiella LPS much like that in the inner core of LPS of S. minnesota. Large differences in reactivity between LPS of different strains belonging to the same O serotype were observed. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of LPS followed by immunoblotting, reactivity of MAb 20 was observed only with the fast-moving fraction possibly representing the nonsubstituted core. No binding was seen with the high-molecular-weight fraction that contained core material substituted with several units of O-antigen building blocks. The chemical basis for these differences in reactivity remains to be established. As far as we know, this is the first report containing comprehensive immunochemical data on the LPS core of K. pneumoniae.

Under iron starvation, Bacteroides fragilis expresses various iron-regulated outer membrane proteins. In this study, a deferrated minimal medium was used in growth experiments, and the role of one of these iron-regulated outer membrane proteins (a 44-kDa protein) in an iron uptake mechanism which acquires iron from heme compounds was elucidated. When a specific 44-kDa protein antiserum was used in a medium with heme as the only iron source, growth inhibition was observed. These results demonstrate that the 44-kDa outer membrane protein plays an important role in the uptake of heme in B. fragilis.

Killing of Proteus mirabilis by human polymorphonuclear leukocytes was tested in the presence of different Bacteroides species. In vitro experiments showed that anaerobic bacteria interfered with the killing of aerobic bacteria. However, this inhibitory effect was not a property of all Bacteroides species. Bacteroides gingivalis W83 showed the greatest inhibitory effect of the five Bacteroides strains tested. Killing of P. mirabilis was inhibited by the culture supernatant of B. gingivalis but not by washed cells. Two factors were found in the supernatant of B. gingivalis to account for the inhibitory effect. One was heat stable with a molecular weight of less than 3,500 and inhibited the killing activity of leukocytes, and the other was heat labile and partly inactivated the complement system. The killing experiments paralleled chemiluminescence measurements.

Detection and genotyping of Chlamydia trachomatis were optimized by using a polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis performed directly with crude cells of cervical scrapes. Different PCR pretreatment methods were evaluated on samples which were positive for C. trachomatis by cell culture. In comparison with DNA extraction and different proteolytic digestion methods, a simple pretreatment of 10 min of boiling appeared to be optimal for PCR amplification. Crude samples (n = 209) were first screened for C. trachomatis by both cell culture and plasmid PCR. Subsequently, positive samples found by plasmid PCR were subjected to a direct omp1 PCR-based RFLP analysis to differentiate C. trachomatis serovars A to K, Ba, Da, and L1 to L3 and serovariant D-. All cervical scrapes that were found positive for C. trachomatis by cell culture (n = 30) were also positive by plasmid PCR and omp1 PCR and could be easily genotyped. In addition, of the culture-negative group, eight samples were found positive by plasmid PCR. Five of these eight samples were also positive by omp1 PCR; of these five, two were positive by a nested omp1 PCR. Genotyping by RFLP analysis of the 35 omp1 PCR-positive samples showed that serovars D, E, and F are the most prevalent types found in cervical scrapes, while serovariant D- was also detected. This study shows that direct PCR and PCR-based RFLP analysis are feasible for detection and genotyping of C. trachomatis in cervical scrapes and are more sensitive than culture-based serotyping.

Vero cell invasiveness was studied for a group of Proteus mirabilis strains isolated from the urinary tract and feces and for a limited group of urinary isolates of Escherichia coli. Experimental conditions affecting this invasiveness were studied. All of the P. mirabilis strains tested were capable of cell invasion, whereas none of the E. coli strains was. Correlation between the hemolytic activity of the P. mirabilis strains and their invasive ability suggested that the bacterial hemolysin may be involved in the invasion process. Other experimental evidence supporting this hypothesis is discussed. The differences in the invasive capacities of P. mirabilis and of E. coli may be important for the apparent differences in the pathogenesis of urinary tract infection by both species.

A method for determination of the amount of polymer film coat actually applied to tablets as a result of aqueous film coating was developed using gel permeation chromatography (GPC). A styrene-based GPC column (Ultrastyrage]R 100A) was found to provide good separation of a commercially available polymer film coat (OpadryR) from other tablet constituents. The assay method is simple, rapid and reproducible with coefficients of variation less than 2.6% in all cases. The assay is sensitive enough to discriminate between tablets containing different levels of microcrystalline cellulose (MCC) when coated simultaneously. The assay was conducted on polymer extracted from the tablets with a solution of 50/50 methanol/methylene chloride. The addition of MCC to tablet formulations was found to increase the amount of film applied, in a competitive coating operation, when all other factors were held constant.

This study examined the extent to which the potentially toxic lead particulates emitted from motor vehicles are absorbed by competitive cyclists. A time trial (n = 5), a road race (n = 5), and a sedentary control group (n = 5) were examined with respect to blood lead (PbB) levels. In the two cycling groups, the PbB levels were measured before and after (1) a time trial (80km) held on a dual carriageway; and (2) a road race (120km) which took place in a rural area. Mean (± SE) resting PbB levels for the sedentary subjects, time trialists, and road racers were 0-442 ± 0041, 0-490 ± 0111 and 0-384 ± 0061 μmoll-1 respectively (p > 005). Mean post-race PbB levels of the time trialists (0-528 ± 0046μmol1minus;1 ) and road racers (0-346 ± 0-024 μmol1minus;1 ) did not differ significantly from the pre-race levels (p > 0-05). However, after their respective races, the mean PbB level of the time trialists was higher than that of the road racers {p < 0-05). Ninety minutes of cycling (70% VO2max) in a laboratory containing approximately 1μgm3 of airborne lead did not affect blood lead levels. All PbB levels complied with EC regulations regarding lead exposure. Despite a positive relationship between the amount of training and the PbB levels (r = 0-64, p < 0-05), competitive cyclists did not evidence abnormal levels of lead absorption. Time trialing on dual carriageways was associated with higher PbB levels than road racing. Further research should examine the PbB levels of a larger sample of competitive cyclists.

The Wingate test has been used as a major test of muscle power whereas isokinetic devices have been used to determine muscle strength. The aim of this study was to examine the relationships between the 30 s Wingate test and tests using repeated knee extensions/flexions on an isokinetic dynamometer (Akron). Ten females and eight males undertook a 30 s Wingate test, six maximal reciprocal contractions of the knee extensors and flexors on the isokinetic dynamometer, and a 30 s test of repeated maximal reciprocal contractions of the knee extensors and flexors. Five minutes after the 30 s tests a blood sample was taken for lactate determination.Significant correlations were obtained for the peak power output (PPO) between the Wingate test and the isokinetic extension (r=0·86, p <0·01) and flexion. tests (r=0·85, p<0·01). Significant correlations were also obtained for the fatigue index (FT) between the Wingate test and the 30s isokinetic test (r = 0·84, p<0·01). Fatigue index was defined as the decline in PPO over time. Values for PPO were significantly higher (p<0·01) in the Wingate test (789 ± 181·6 W) than the corresponding extension (611·45 ± 222·7 W) and flexion (336·27 ± 182·4 W) values in the isokinetic maximum torque test. Post-exercise blood lactate concentrations were also significantly higher (p<0·01) for the Wingate test (10·02± 1·85 mmoll-1 ) than for the 30s isokinetic test (4·14±1·1·9mmoll-1 ). There was a weak but significant correlation between blood lactate for the Wingate and 30 s isokinetic test (r=0·51, p<0·05). These results suggest that the isokinetic tests used in this study are useful measures of anaerobic power.

The sensitivities of three methods of detection of Mycoplasma pneumoniae by a 16S rDNA PCR were compared by using a serial dilution of M. pneumoniae. These methods consisted of a PCR performed directly on cells after a proteinase K pretreatment (direct PCR), a PCR after purification of nucleic acids (DNA-PCR), and a PCR with rRNA sequences as the target after reverse transcription. The direct PCR and the reverse transcription PCR had a sensitivity of 1.5 CFU (approximately 250 genomes). By purification, a 10-fold loss of target DNA occurred, as shown by a 10-fold decrease in sensitivity (15 CFU) of the DNA-PCR. The presence of an excess of human background DNA did not influence the sensitivity of either PCR. The direct PCR was evaluated on samples from patients with respiratory complaints. Direct PCR amplification was possible in 94.9% of the samples, which were tested by amplification of a 326-bp fragment of the beta-globin gene, which was performed to test for the suitability of amplification. Nucleic acid purification was performed on the beta-globin-negative samples, after which only 2% remained negative. A positive correlation between the direct M. pneumoniae PCR and serology, as tested by the microparticle agglutination assay (MAG assay), was found in 88.1% of the cases. A positive MAG assay result was found for samples from 10 (17%) of the patients; samples from 6 (10.2%) of these patients were also positive by PCR. Samples from three patients were found to be positive by the M. pneumoniae PCR and negative by the MAG assay. Persistence of M. pneumoniae, as detected by PCR was observed in three patients. These results indicate that the direct PCR with 16S rDNA could prove to be useful in the detection of M. pneumoniae in respiratory tract samples, although more studies are needed to evaluate the correlation between clinical symptoms and positive test results.

A recombinant 23-kDa protein (rBPI23) derived from human bactericidal/permeability-increasing protein (BPI) possesses potent endotoxin-neutralizing abilities in vitro and in vivo. Binding of rBPI23 to those endotoxins (lipopolysaccharides [LPSs]) encountered clinically would be a prerequisite for efficacy in decreasing mortality among patients suffering from gram-negative sepsis and shock, a disease state in which an etiological role for LPS has been implicated. rBPI23 binds well to lipid A (n = 7), to rough-mutant O-chain-deficient LPS (n = 18, Re to Ra chemotypes), to lipid A-core covalently linked to the O chain, to LPSs from clinically relevant serotypes (n = 100), and to bacterial cells (n = 88) of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, the species most often implicated in clinical gram-negative sepsis and shock. Significant binding of rBPI23 to these antigens took place at rBPI23 concentrations of 1 to 500 ng/ml (median, 16 to 32 ng/ml). Binding did not involve 3-deoxy-D-manno-octulosonate of the inner core. Determining the exact epitope recognized by rBPI23 would require further studies with synthetic lipid A substructures. The demonstrated ability of rBPI23 to universally bind LPS provides a sound basis for further testing of its endotoxin-neutralizing abilities, including clinical trials.

Lactoferrin (LF), a cationic 80-kDa protein present in polymorphonuclear leukocytes and in mucosal secretions, is known to have antibacterial effects on gram-negative bacteria, with a concomitant release of lipopolysaccharides (LPS, endotoxin). In addition, LF is known to decrease LPS-induced cytokine release by monocytes and LPS priming of polymorphonuclear leukocytes. Its mechanism of action is incompletely understood. We have now demonstrated by in vitro-binding studies that LF binds directly to isolated lipid A and intact LPS of clinically relevant serotypes of the species which most frequently cause bacteremia (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), as well as to lipid A and LPS of mucosal pathogens (among others, Neisseria meningitides and Haemophilus influenzae). Binding to LPS was inhibitable by lipid A and polymyxin B but not by KDO (3-deoxy-D-manno-octulosonate), a glycoside residue present in the inner core of LPS. Binding of LF to lipid A was saturable, and an affinity constant of 2 x 10(9) M-1 was calculated for the LF-lipid A interaction. Our data may explain, in part, the mechanism whereby LF exerts its antibacterial and anti-endotoxic effects. Further studies on the ability of LF to block the detrimental effects of LPS, both in vitro and in vivo, are warranted.

Two experimental mouse models were tested for their suitability in measuring urinary virulence of Proteus mirabilis. In the first model, the kidney-infecting dose and lethal dose were measured. In the second model, the kinetics of the numbers of bacteria in the kidneys and other organs of the mouse were monitored for 13 h after injection.