Evaluation of oxidant-antioxidant balance in patients on maintenance haemodialysis: a comparative study of dialyzers membranes.

BACKGROUND: Haemodialysis (HD) exacerbates oxidative stress (OS). The polymethyl-methacrylate (PMMA)-BK-F membrane ameliorates OS and inflammation markers compared to polyacrylonitrile (PAN/AN69) and cellulose membranes. This may be due to the size of pore radius, high flux or other specific properties of PMMA membranes. AIM: To compare OS and inflammatory status in HD-treated end stage renal disease patients with membranes of different pore size radius and flux. METHODS: 47 patients of both sexes were studied. The HD membranes with which the patients were normally treated were changed to BK-P or B-3 membranes for 6 months. Intracellular and extracellular components of the oxidant-antioxidant balance (OAB), C-reactive protein (CRP), beta2-micro-globulin (beta2mu-globulin), albumin and transferrin were measured. RESULTS: A significant decrease in red cell membrane thiobarbituric acid reacting substances and an increase in cytosolic superoxide dismutase (SOD) and plasma total antioxidant substances were observed in all patients after 6 months of treatment with BK-P and B-3 membranes except SOD and CRP in patients previously dialysed with triacetate cellulose membranes. Albumin and transferrin remained unmodified. beta2mu-globulin significantly decreased after treatment with PMMA membranes. CONCLUSION: BK-P and B-3 HD membranes improved the OAB, beta2mu-globulin and CRP compared to PAN/AN69 and cellulose diacetate membranes.

Epidemiology and clinical presentation of gonorrhoea in England and Wales: findings from the Gonococcal Resistance to Antimicrobials Surveillance Programme 2001-2006.

OBJECTIVE: To analyse the enhanced data for gonorrhoea cases in England and Wales collected by the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) to better inform health policy and targeted interventions. METHODS: GRASP data obtained annually from sentinel genitourinary medicine (GUM) clinics between June to August during 2001-6 were analysed. RESULTS: A total of 12 282 cases of gonorrhoea were reported during the study period, with a decline over time primarily in heterosexual patients of black ethnicity. 73% of women, 47% of heterosexual men and 22% of men who have sex with men (MSM) were aged under 25. Most infected women reported a single sexual partner in the previous 3 months, whereas most heterosexual men and MSM reported two or more partners. A history of gonorrhoea was reported by 42% of MSM, 30% of heterosexual men and 20% of women. Excluding HIV, women were more likely than men to have a concurrent STI at diagnosis, most commonly chlamydia (50% vs 27% p<0.0005). Rectal gonococcal infections were reported in 35% and HIV co-infection in 31% of MSM. Compared to HIV negative MSM, those co-infected with HIV were older (median 35 years vs 28 years) and were more likely to attend a London site (70% vs 52%, p<0.0005); have a concurrent sexually transmitted infection (STI) (28% vs 20%, p = 0.002); have a history of gonorrhoea (66% vs 36%, p<0.0005) and have more sexual partners (average 6.8 vs 4.3). CONCLUSION: Gonorrhoea is concentrated within specific groups who are at high risk of repeat infections and concurrent STIs including HIV. Targeted interventions of proved effectiveness are urgently required.

Gonorrhoea in young heterosexuals attending urban STD clinics in Britain: a cross-sectional survey.

Young people in the UK bear the brunt of sexually transmitted infections, in particular of gonorrhoea. We aimed to assess whether young people with gonorrhoea (under 21 years) attending sexual health clinics differed from older individuals with gonorrhoea in their behavioural and clinical characteristics and management outcomes. The results of this cross-sectional study suggest that young people were more likely to be female (66.2% vs 34.1%), have concurrent infection with Chlamydia trachomatis (55.4% vs 30.2%) and a history of recent gonococcal infection (81.3% vs 35.5%) if they ever had gonorrhoea. Young women were more likely to experience treatment delay and not to attend for follow-up than older women. Resistance to ciprofloxacin was high in both age groups but the prevalence of penicillinase-producing Neisseria gonorrhoeae was higher in older patients (11.5% vs 1.3%). Different management protocols for young and older patients with gonorrhoea may need to be considered.

Sources of inner radiation zone energetic helium ions: cross-field transport versus in-situ nuclear reactions.

Radial transport theory for inner radiation zone MeV He ions has been extended by combining radial diffusive transport, losses due to Coulomb friction and charge exchange reaction with local generation of 3He and 4He ions due to nuclear reactions taking place on the inner edge of the inner radiation zone. From interactions between high energy trapped protons and upper atmospheric constituents we have included a nuclear reaction yield helium flux source that was numerically derived from a nuclear reaction model originally developed at the Institute of Nuclear Researches of Moscow, Russia and implemented in the computer system at the University of Campinas, Brazil. Magnetospheric transport computations have been made covering the L-shell range L=1.0 to 1.6 and the resulting MeV He ion flux distributions show a strong influence of the local nuclear source mechanism on the inner zone energetic He ion content.

Dynamics of the low altitude secondary proton radiation belt.

At the interface between the upper atmosphere and the radiation belt region, there exists a secondary radiation belt consisting mainly of energetic ions that have become neutralized in the ring current and the main radiation belt and then re-ionized by collisions in the inner exosphere. The time history of the proton fluxes in the 0.64-35 MeV energy range was traced in the equatorial region beneath the main radiation belts during the three year period from 21 February 1984 to 26 March 1987 using data obtained with the HEP experiment on board the Japanese OHZORA satellite. During most of this period a fairly small proton flux of -1.2 cm-2 S-1 sr-1 was detected on geomagnetic field lines in the range 1.05 < L < 1.15. We report a few surprisingly deep and rapid flux decreases (flux reduction by typically two orders of magnitude). These flux decreases were also long in duration (lasting up to three months). We also registered abrupt flux increases where the magnitude of the proton flux enhancements could reach three orders of magnitude with an enhancement duration of 1-3 days. Possible reasons for these unexpected phenomena are discussed.

Psychosocial factors in later life depression.

The purpose of this paper has been to assess the psycho-social factors in the onset and course of late life depressions. The sample consisted of 100 consecutive depressed in-patients, over 65 year-olds and 100 consecutive cases under 65. Our findings indicate that the number of precipitating factors was higher in the elderly group in comparison with the control group. Patients whose depression comes on in old age experienced more life events before the illness than those whose depression began under the age of 65. The clinical course of the depressive illness tends to be related to the precipitating event, patients experience psycho-social factors having longer depressive episodes.

European Surveillance of Sexually Transmitted Infections (ESSTI): the first combined antimicrobial susceptibility data for Neisseria gonorrhoeae in Western Europe.

OBJECTIVES: To conduct a sentinel surveillance study for antimicrobial resistance in Neisseria gonorrhoeae in Western Europe in 2004 as part of the European Surveillance of Sexually Transmitted Infections (ESSTI) Programme. METHODS: Gonococcal isolates were collected from centres in 12 countries and transferred to two reference centres for testing. The same methodology of agar dilution was used to determine susceptibility to a range of antimicrobials used for the treatment of gonorrhoea including azithromycin, ceftriaxone, ciprofloxacin, penicillin and tetracycline. Quality control between the two laboratories was assessed during the testing. RESULTS: A total of 1055 gonococcal isolates were collected, of which 965 (91.5%) were retrievable for susceptibility testing. Resistance was found to be high to ciprofloxacin (30.9%), but also present to penicillin (21.3%) and tetracycline (59.8%). Azithromycin resistance was above 5%, the first time this has been documented in Europe. Three isolates had a low level of resistance to ceftriaxone. With regard to quality control between the two reference laboratories, 92% of MIC results were within two dilutions. CONCLUSIONS: These are the first sentinel surveillance data for Western Europe for N. gonorrhoeae and they have implications for choice of antimicrobial for treatment of gonorrhoea on a European and a local level. This is the start of the formation of a European gonococcal antimicrobial surveillance programme (EURO-GASP).

The prevalence of proline iminopeptidase negative Neisseria gonorrhoeae throughout England and Wales.

BACKGROUND: The accurate laboratory identification of Neisseria gonorrhoeae is an essential element of the diagnosis of gonorrhoea and is particularly important for medicolegal cases. The detection of proline iminopeptidase (Pip) activity is widely used as a marker for gonococci, although Pip negative N gonorrhoeae isolates have been shown to generate false negative identifications when using biochemical kits. This study aimed to determine the frequency of Pip negative gonococci in England and Wales. METHODS: A total of 2055 isolates were collected from consecutive patients attending 26 genitourinary medicine centres as part of the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP). Upon receipt the identity of all isolates was confirmed using N gonorrhoeae specific monoclonal antibodies and the Pip status was determined using the Gonochek II kit. RESULTS: The overall prevalence of Pip negative isolates was found to be 4.33%. Significant geographical variation was observed between isolates from centres outside London (p< or =0.001). Variation was also observed within London between the nine different clinics submitting isolates (p = 0.025). There was also a higher frequency of these isolates among men who have sex with men (p< or =0.001), which may account for geographical variations. CONCLUSION: Pip negative N gonorrhoeae isolates are a very serious cause for concern as currently all biochemical test kits available within the United Kingdom require the presence of the Pip enzyme for an unambiguous identification of this pathogen. Raising awareness of the current prevalence of Pip negative N gonorrhoeae isolates is critical for the successful control of gonorrhoea.

Comparability of laboratory diagnosis and antimicrobial susceptibility testing of Neisseria gonorrhoeae from reference laboratories in Western Europe.

OBJECTIVES: The aim of this study was to obtain information on the comparability of methods for the laboratory diagnosis of bacterial sexually transmitted infections (STIs) that contribute to the surveillance data in the European Union (EU) and Norway. Surveillance of bacterial STIs is important across Europe because of the movement of individuals between countries at a time when STI incidence appears to be increasing in many countries. METHODS: Cross-sectional survey using a questionnaire, to provide information on laboratory methods for the diagnosis of gonorrhoea, and a panel of strains of Neisseria gonorrhoeae, to compare susceptibility testing, was circulated to laboratories in the EU and Norway. RESULTS: The questionnaire revealed marked diversity in the methodologies used for the laboratory diagnosis of gonorrhoea across Europe. Fourteen laboratories participated in an exchange of gonococcal strains to assess the methodology in current use for susceptibility testing. The methods included disc diffusion and determination of the minimum inhibitory concentration (MIC) using agar dilution and/or Etest. There was no common method used, each centre varied from another by at least one procedure. Overall agreement using all methods was >70%, being highest for ceftriaxone and lowest for tetracycline. Disc diffusion gave the lowest agreement with the consensus compared with determination of MIC by either agar dilution or Etest. CONCLUSIONS: A variety of methods were used across the EU and Norway for the laboratory diagnosis and susceptibility testing and resulted in poor concordance between laboratories on the definition of resistant N. gonorrhoeae. This suggests that there is a need for greater standardization of methodology that provides surveillance data in the EU and Norway.

The epidemiology of ciprofloxacin resistant isolates of Neisseria gonorrhoeae in Scotland 2002: a comparison of phenotypic and genotypic analysis.

OBJECTIVES: To characterise all isolates with reduced susceptibility or resistance to ciprofloxacin received by the Scottish Neisseria gonorrhoeae Reference Laboratory (SNGRL) in 2002 using N gonorrhoeae multi-antigen sequence typing (NG-MAST); to compare NG-MAST with conventional typing and to describe the epidemiology of ciprofloxacin resistant gonorrhoea in Scotland in 2002. METHODS: Isolates were characterised on receipt by auxotyping and serotyping (A/S typing), and antibiotic susceptibility testing, and retrospectively by NG-MAST. Epidemiological data were requested for all isolates in the study. RESULTS: The 106 isolates were separated into more sequence types (ST) than A/S classes (44 versus 17). All isolates within a sequence type had the same serotype, were homogeneous with respect to ciprofloxacin resistance category, but were sometimes heterogeneous with respect to auxotype or plasmid borne resistance to penicillin. Combined NG-MAST and epidemiological data revealed sustained transmission of several gonococcal strains predominantly within Greater Glasgow and Lothian. Clusters of isolates were associated with transmission within the United Kingdom, whereas isolates with unique STs were associated with foreign travel (p < 0.0001). CONCLUSIONS: NG-MAST is more discriminatory than A/S typing. Ciprofloxacin resistant gonococcal isolates in Scotland are heterogeneous, with endemic spread of some strains occurring predominantly in Greater Glasgow and Lothian.

Susceptibility of gonococci isolated in London to therapeutic antibiotics: establishment of a London surveillance programme. London Gonococcal Working Group.

OBJECTIVES: To establish the in vitro susceptibility of gonococci isolated in the London area to antibiotics in current therapeutic use and to establish a sentinel surveillance system for monitoring trends in antibiotic resistant gonorrhoea in London. METHODS: Isolates of Neisseria gonorrhoeae from consecutive patients attending genitourinary medicine clinics at 10 hospitals in the London area were collected over a 3 month period, May to July 1997. The susceptibility to penicillin, ciprofloxacin, tetracycline, and spectinomycin was determined for each isolate. Isolates exhibiting either plasmid or chromosomally mediated resistance were additionally tested for susceptibility to agents used as alternative treatments including azithromycin, ceftriazone, and ofloxacin. The resistant isolates were also tested for plasmid profiles (penicillinase producing N gonorrhoeae, PPNG), type of tetM determinant (tetracycline resistant N gonorrhoeae, TRNG), and presence of gyrA and parC mutations (quinolone resistant N gonorrhoeae, QRNG). RESULTS: A total of 1133 isolates were collected which represents > 95% of the total gonococci isolated in the 3 months. Plasmid mediated resistance was exhibited by 48 (4.2%) isolates; six (0.5%) were PPNG, 15 (1.3%) were PP/TRNG, and 27 (2.4%) were TRNG. The majority of PPNG (18 of 20 tested) carried the 3.2 MDa penicillinase plasmid whereas the two types of tetM determinant were more evenly distributed. High level resistance to ciprofloxacin was detected in four (0.4%) isolates and double mutations were found in the quinolone resistance determining region (QRDR) of the gyrA gene in three QRNG with MICs of 16 mg/l and a single mutation in one isolate with a MIC of 1 mg/l to ciprofloxacin. No parC mutations were found. Of the remaining 1081 isolates, 86 (8.0%) were chromosomally mediated resistant N gonorrhoeae (CMRNG). CONCLUSIONS: A unique collection of gonococcal isolates has been established which can be used as a baseline for surveillance of susceptibility to antibiotics and for epidemiological purposes.

Rise in gonorrhoea in London, UK. London Gonococcal Working Group.

We report an alarming 34.9% overall increase in the number of gonococcal infections diagnosed during the same 3 month study period during 3 years. Between 1997 and 1998, an increase of 12.1% was detected, with a larger increase between 1998 and 1999, of 20.4%.

[Health behavior of schoolchildren in a metropolitan area of Madrid]. / Hábitos de salud de los escolares de una zona periurbana de Madrid.

BACKGROUND: To describe health behavior of students about diet, alcohol and tobacco, dental-oral hygiene, leisure time activities and interpersonal relations. METHODS: 942 Students have been carried out. Children come from six schools of the town of Parla (in the south of Madrid). They are from 9 to 14 years old. The instruments have been made for this study, helping by teachers of EGB. RESULTS: 50% of the students doesn't eat any food at 12 o'clock, after drinking a glass of milk only at breakfast (8 o'clock). 10% never eats greens. 37% of the children in the upper level drinks alcohol sometimes and, in the same level, 12% smokes sometimes. Around 25% of children brush their teeth three times in the day. The students watch television three hours and half, means, in the day. The communication with the teacher is evaluated from "not too bad" to "bad" by 70% of the students of upper level. 42% and 39.4% of the children talks about abortion and contraceptives, respectively, with nobody. CONCLUSIONS: In general, girls have better habits than boys. Only exercise is more prevalent in the boys than in the girls.

Gonorrhoea in London: usefulness of first line therapies.

OBJECTIVES: To determine the true prevalence and patterns of resistance of Neisseria gonorrhoeae to antimicrobial agents used for therapy in London. METHODS: A longitudinal study of a representative sample of isolates of N gonorrhoeae linked to demographic data of infected patients was undertaken. Isolates were collected from consecutive patients attending genitourinary medicine clinics in the North and South Thames regions of London during 3 months of each of 4 years, 1997-2000. Prevalence of plasmid mediated resistance to penicillin and chromosomally mediated resistance to penicillin and ciprofloxacin was determined by susceptibility testing. The association of antimicrobial resistance among gonococci with sexual orientation of the patient and country of acquisition of infection was determined. RESULTS: Numbers of gonococcal isolates collected over the same time period between 1997-2000 have increased by 74%. Plasmid mediated resistance to penicillin was low but has risen above 5% in 2000. Chromosomal resistance to penicillin has fallen below the 5% level but total resistance to penicillin, plasmid and chromosomally mediated, was above 5% in all 4 years. The incidence of resistance and reduced susceptibility to the alternative therapeutic choice, ciprofloxacin, is low but numbers are increasing in each year. High level resistance, to both penicillin and ciprofloxacin, has generally been found among heterosexual men and is often acquired abroad. However, there is some evidence of a change to endemic spread in 2000. CONCLUSIONS: This surveillance programme shows that the epidemiology of gonorrhoea in London is changing with increasing numbers and changing patterns of resistance. If gonorrhoea is to be controlled and targets set by the sexual health strategy are to be met, intervention with effective and appropriate antimicrobial agents is essential.

Detection of mixed infection of Neisseria gonorrhoeae.

We report the first published evidence, to our knowledge, of the demonstration of the potential existence of mixed infections of Neisseria gonorrhoeae in vivo through the use of a highly discriminatory genotypic technique.

Persistence of two genotypes of Neisseria gonorrhoeae during transmission.

Isolates of Neisseria gonorrhoeae were tested using a highly discriminatory typing method, opa typing, to examine the genetic diversity over a 2-year study period of isolates from all consecutive patients with gonorrhea attending the Genitourinary Medicine clinic in Sheffield, United Kingdom. Two opa genotypes were detected throughout the 2-year time period and comprised 41% of all strains tested. The persistence of two opa types was investigated further to determine the apparent genetic stability, by examining the ability of isolates to undergo intragenic and intergenic recombination and mutation in vitro. Intragenic recombination or mutation involving the opa genes of N. gonorrhoeae in the selected isolates was not detected, but intergenic recombination did occur. opa genes of N. gonorrhoeae in vivo appear to diversify primarily through intergenic recombination. Intergenic recombination in vivo would require the presence of a mixed gonococcal infection, in which an individual is concurrently colonized with more than one strain of N. gonorrhoeae. We propose that the level of diversity of opa genotypes in a population is linked to the degree of sexual mixing of individuals and the incidence of mixed infections of N. gonorrhoeae.

Identification of spherical virus particles in digitized images of entire electron micrographs.

New methods are described that should facilitate high-resolution (5-10 A) image reconstructions from low-dose, low-contrast electron micrographs of frozen-hydrated specimens and processing of large, digital images produced by new imaging devices and modern electron microscopes. Existing techniques for automatic selection of images of individual biological macromolecules from electron micrographs are inefficient or unreliable. We describe the Crosspoint method (CP), which produces good quality solutions with relatively small miss rates and few false hits, and an extension of this method along with a procedure for refining its solution. Two algorithms for processing large images, one based on image subsampling, the other on image decomposition, are described. A large image is first compressed (e.g., by subsampling) and the CP method is applied to the compressed image to produce an initial solution. The information gathered at this stage is used to cut the original image into subimages and then to refine the particle coordinates in each subimage. An interactive environment for experimenting with particle identification methods is described.

Evaluation of the discriminatory power of typing methods for Neisseria gonorrhoeae.

A panel of 18 strains of Neisseria gonorrhoeae, known to be temporally and geographically diverse, was used to evaluate a number of typing systems, including conventional auxotyping and serotyping and the molecular methods of arbitrarily primed PCR (AP-PCR), amplified ribosomal-DNA restriction analysis (ARDRA), opa typing, and pulsed-field gel electrophoresis (PFGE). The discriminatory power of the different typing methods were determined with a collection of 87 clinical isolates from commercial sex workers in Indonesia, and Simpson's index of diversity was calculated. Of the two traditional techniques, auxotyping and serotyping, the latter gives the highest discriminatory index (DI) (DI, 0.846). The combination of auxotyping and serotyping yields a high DI (DI, 0. 928). D11344- and D8635-primed PCR showed low DIs of 0.608 and 0.622, respectively, but a combination of the two primers had a DI of 0. 849. The combination of serotyping with D11344-primed or D8635-primed PCR resulted in DIs of 0.936 and 0.937, respectively. ARDRA revealed a low DI of 0.743 alone but a DI of 0.955 in combination with serotyping. PFGE using the restriction enzyme BglII and opa typing produced the highest discrimination (DIs, 0.997 and 0. 996, respectively) for isolates of N. gonorrhoeae.