Xenorhabdus spp. These metabolites not only have diverse chemical structures but also have a wide range of bioactivities with medicinal and agricultural interests such as antibiotic, antimycotic and insecticidal, nematicidal and antiulcer, antineoplastic and antiviral. It has been known that cultivation parameters are critical to the secondary metabolites produced by microorganisms. Even small changes in the culture medium may not only impact the quantity of certain compounds but also the general metabolic profile of microorganisms. Manipulating nutritional or environmental factors can promote the biosynthesis of secondary metabolites and thus facilitate the discovery of new natural products. This work was conducted to evaluate the influence of nutrition on the antibiotic production of X. bovienii YL002 and to optimize the medium to maximize its antibiotic production.The production of secondary metabolites with antibiotic properties is a common characteristic to entomopathogenic bacteria X. bovienii YL002. Glycerol and soytone were identified as the best carbon and nitrogen sources that significantly affected the antibiotic production using one-factor-at-a-time approach. Response surface methodology (RSM) was applied to optimize the medium constituents  for the antibiotic production of X. bovienii YL002. Higher antibiotic activity (337.5 U/mL) was obtained after optimization. The optimal levels of medium components were (g/L): glycerol 6.90, soytone 25.17, MgSO4·7H2O 1.57, (NH4)2SO4 2.55, KH2PO4 0.87, K2HPO4 1.11 and Na2SO4 1.81. An overall of 37.8% increase in the antibiotic activity of X. bovienii YL002 was obtained compared with that of the original medium.Nutrition has high influence on the antibiotic production of X. boviebii by medium optimization using RSM. The results strongly support the use of RSM for medium optimization. The optimized medium not only resulted in a 37.8% increase of antibiotic activity, but also reduced the numbers of experiments. The chosen method of medium optimization was efficient, simple and less time consuming. This work will be useful for the development of X. bovienii cultivation process for efficient antibiotic production on a large scale, and for the development of more advanced control strategies on plant diseases.To the best of our knowledge, there are no reports on antibiotic production of  Xenorhabdus is a unique genus of bacteria, the species (strains) of which are symbiotically associated with entomopathogenic nematode belonging to the genus Steinernema. The primary (1°) forms of the bacteria are carried in the intestine of the infective dauer juvenile (IJ) developmental stage of the nematode. The IJ penetrates an insect host and releases the bacteria into the hemocoel of the host. The bacteria multiply rapidly and produce various metabolites which can overcome the insect immune system [Xenorhabdus spp. is known, and several compounds with antibiotic activity have been isolated and identified. These include indoles [ primary ° forms oe system -4. By doe system . The ant indoles , xenorha indoles , xenocou indoles , nematop indoles , benzyli indoles , xenorti indoles , and cyc indoles . These mX. bovienii has been known to produce two classes of antibiotics, indoles and dithiolopyrrolones , which could inhibit the growth of Botrytis cinerea, Phytophthora capsici, and P. ultimum[X. bovienii strain A2 appears to be unique in the diversity of small-molecule antimicrobial compounds since four indoles, several xenorhabdins, xenomins and xenorxides have been isolated from this strain alone [in vitro tests that the antibiotics from X. bovienii may offer a good opportunity for the control of diseases caused by some species of plant pathogenic fungi. X. bovienii metabolites can suppress P. infestans on potato leaves with only slight phytotoxicity [X. bovienii exhibited 100% inhibition effect on P. cactorum lesions of pecan leaves [X. bovienii YL002 showed potent therapeutic and protective effects against B. cinerea on tomato plants and P. capsici on pepper plants [. ultimum. X. boviin alone . These ctoxicity . The metn leaves . Similarr plants .Xenorhabdus spp. differs qualitatively and quantitatively depending on the strains and species of bacteria and their culture conditions. No antibiotic activity was detected, using an agar diffusion assay, from the metabolites of Xenorhabdus spp. cultured in 1% peptone water. However, other media have been used successfully for antibiotic production, including yeast extract broth and its modifications [It has been known that cultivation parameters are critical to the secondary metabolites produced by microorganisms. Even small changes in the culture medium may not only impact the quantity of certain compounds but also the general metabolic profile of microorganisms . In partications ,19, Luriications  and TSB ications . These rications .X. nematophila ATCC19061, the best studied strain of these bacterial symbionts, clearly outnumbers the known secondary metabolites of these organisms [Recently, whole-genome sequencing programmes have revealed that the biosynthetic potential of microorganisms has been greatly underexplored, relying as it does on traditional approaches. In fact, the number of genes encoding biosynthetic enzymes in various bacteria including rganisms . The majrganisms . For exarganisms . TherefoX. bovienii YL002, a strain isolated from its nematode symbiont Steinernema sp YL002, which was obtained from the soil of Yangling, China. A stepwise optimization strategy was performed (1) screening the original medium; (2) selecting the best carbon and nitrogen sources that significantly affect antibiotic production using one-factor-at-a-time approach; (3) RSM optimization of these significant ingredients by central composite design (CCD).Response surface methodology (RSM) is a commonly used method to find the optimal fermentation conditions for various microorganisms, and also an efficient statistical technique for optimization of multiple variables with minimum number of experiments -26. The X. bovienii YL002 . The antibiotic activity in glucose, fructose, maltose, sucrose, lactose and starch ranged from 153.3 to 160.0 U/mL. The antibiotic activity with the addition of crude carbon sources (corn flour) was 130.0 U/mL, and the minimum (123.3 U/mL) in bran. As for the various nitrogen sources, soytone (286.7 U/mL) and proteose peptone (276.7 U/mL) favored antibiotics production, and the antibiotic activity had no significant differences. Lower antibiotic activities were observed with urea and crude nitrogen sources . Thus, glycerol and soytone were chosen as the source of carbon and nitrogen for further experiments, respectively. Similar results were obtained in the study on the determination of the effect of various carbon sources and nitrogen sources on the antibiotic activity of Xenorhabdus sp. D43, maltose and glycerol had the strongest effect on antibiotic activity of the strain [X. nematophila BJ was glucose and soytone [X. nematophila, the optimal carbon sources and nitrogen sources for antibiotics production was glucose and peptone [The carbon and nitrogen sources are the important constituents to be considered which are reported to have highly influence on the antibiotic production by dus spp. ,31,32. B peptone 6.7 U/mL  peptone . The dis4, MgCl2, NaCl, KH2OP4, KNO3 and (NH4)2SO4 favored antibiotic production by Xenorhabdus sp. D43, but antibiotic production with the addition of Zn(NO3)2 and CuSO4 was found to be low [4, (NH4)2SO4, KH2OP4, K2HOP4 and Na2SO4. Therefore, the minerals for further CCD design were defined as the total concentration of the minerals of YSG medium and kept the proportion of diversified components. Subsequently, experiments were conducted for further optimization of these selected nutrients employing RSM.It is known that several trace elements are essential for microbial growth because of their involvement in metalloenzymes or as enzyme activators. In secondary metabolism, zinc, iron and manganese are the most important trace elements . MgSO4, o be low . In YSG,After determination of carbon and nitrogen sources in the medium, the effects of concentration of medium constituents on the antibiotic activity with the producer YL002 were further investigated. The range and the levels of the variables investigated in this study are given in Table X1), soytone (X2) and minerals (X3), a second-order polynomial model (Eq.2) was proposed to calculate the optimum levels of these variables. By applying the multiple regression analysis on experimental data, a second-order polynomial model in coded unit explains the role of each variable and their second-order interactions in antibiotic activity.In order to evaluate the relationship between dependent and independent variables and to determine the maximum antibiotic activity production corresponding to the optimum levels of glycerol  with 10 terms contains three linear terms, three quadratic terms and three two factorial interactions. After the neglect of insignificant terms , the model Eq. (3) was modified to reduced fitted model Eq. (4):where X1, X2 and X3 were significant at 5% level . Minerals also had significant effect on the antibiotics activity at linear terms (XP3 < 0.007216). Partial eta squared was used as a measure of effect size. Glycerol had highest impact on the antibiotics production as given by highest linear partial eta squared (0.758851), followed by soytone (0.728744) and minerals (0.530603). The result also could be explained by the Pareto chart of effects . These suggest that the concentrations of glycerol, soytone and minerals have a direct relationship with the antibiotic activity in this particular complex medium. The result fitted in the previous work, in which glycerol, soytone and minerals influence bacterial growth and antibiotic production [Quadratic response surface regression designs are a hybrid type of design with characteristics of both polynomial regression designs and fractional factorial regression designs. Quadratic response surface regression designs contain all the same effects of polynomial regression designs to degree 2 and additionally the 2-way interaction effects of the predictor variables. Each effect could be estimate independently due to the orthogonal design. In order to evaluate influential factors/terms in the quadratic RSM, an ANOVA was established, and it can be seen from the degree of significance that the linear term of el Table . Among toduction ,31-33.t-test and P-value. The larger the magnitude of t-test and smaller the P-value, the more significant is the corresponding coefficient. The positive coefficients for X1, X2 and X3 indicate a linear effect to increase antibiotic activity. The negative coefficient for X12, X22and X32 showed negative effects on the antibiotics production, indicating that the antibiotics production increased as the level of these factors increased and decreased as the level of these parameters increased above certain values.The significance of each coefficient in this study was determined by Student's P value of the Fisher's F-test  = 4.64), indicating that the treatment differences were highly significant. This proved that the model equation as expressed in Eq. (4) provides a suitable model to describe the response of the experiment pertaining to antibiotic activity. The model also showed a statistically insignificant lack of fit, as is evident from the lower calculated F-value (0.843414) than the tabulated F-value  = 10.5) even at the 0.01 confidence level. The model was found to be adequate for prediction within the range of variables employed. The goodness of fit of the model based on RSM can be checked by the coefficient of determination (R2), which provides a measure of how much variability in the observed response values can be explained by the experimental factors and their interactions. The R2 value is always between 0 and 1. The closer the R2 value is to 1.00, the stronger the model is and the better it predicts the response. In this case, the coefficient of determination R2 = 0.926233, which implied that antibiotic activity was attributed to the given independent variables. The R2 also indicated that only 7% of the total variations were not explained by the model. The value of the adjusted determination coefficient (adjusted R2 = 0.883203) was also high to indicate a high significance of the model. These measures indicated that the accuracy and general ability of the polynomial model was good and that analysis of the response trends using the model was reasonable. A higher value of the correlation coefficient, R = 0.96241, indicates a good agreement between the experimental and predicted values of antibiotic activity. These measures indicate that the accuracy and general ability of the polynomial model are good and that analysis of the response trends using the model is reasonable.The results of the second-order response surface model in the form of analysis of variance (ANOVA) are given in Table Y (antibiotic activity) corresponding to particular values of the regress variables. In predicting new observations and in estimating the mean response at a given point, one must be careful about extrapolating beyond the region containing the original observations. It is very possible that a model that fits well in the region of the original data will no longer fit well outside the region. Figure A regression model can be used to predict future observations on the response Y. Both of the plots are satisfactory, so we conclude that the empirical model is adequate to describe the antibiotic activity by response surface.Usually, it is necessary to check the fitted model to ensure that it provides an adequate approximation to the real system. Unless the model shows an adequate fit, proceeding with the investigation and optimization of the fitted response surface likely give poor or misleading results. The residuals from the least squares fit play an important role in judging model adequacy. The assumptions for randomness, normality and constant variances of the residuals are all verified by the normal probability plot and the residual plot. The normal plot of residuals is shown in Figure The 3D response surface and the 2D contour plots described by the regression model are drawn to illustrate the effects of the independent variables, and interactive effects of each independent variable on the response variables. The shape of the corresponding contour plots indicates whether the mutual interactions between the independent variables are significant or not. An elliptical nature of the contour plots indicates that the interactions between the independent variables were significant. From the 3D response surface plots and the corresponding contour plots, the optimal values of the independent variables and the corresponding response could be predicted, and the interaction between each independent variable pair could be understood. The maximum predicted value is indicated by the surface confined in the smallest ellipse in the contour diagram.Figure Figure Figure X1, X2 and X3) variables produce the most desirable predicted responses on the dependent variable (Y). The profiles for predicted response and the desirability level for factors 2SO4 2.55 g, KH2PO4 0.87 g, K2HPO4 1.11 g, Na2SO4 1.81 g) give optimum antibiotic activity at an optimum desirability score of 0.86178 (305.55 U/mL). These profiles suggest that an increase in the concentration of glycerol, soytone and mineral above the optimized levels will not increase the antibiotic activity significantly. The verification of the results using the optimized medium was accomplished by carrying out shake-flask experiments. The maximum antibiotic activity unit obtained experimentally was found to be 337.5 U/mL. This is obviously in close agreement with the model prediction (305.55 U/mL). As a result, the model developed was considered to be accurate and reliable for predicting the production of antibiotics by X. bovienii YL002. After optimization, the antibiotic activity was improved by 15.7% and 37.8%, compared with mean observed response and at zero level of all variables (291.7 U/mL) and YSG medium (245.0 U/mL).The desirability function to obtain an optimum antibiotic activity was fitted by the least square method assigning the antibiotic activity at the observed low (222.49 U/mL) and high (318.87 U/mL) values for a corresponding desirability of 0 and 1, respectively, and the profiles were plotted using Response Surface Regression in STATISTICA 8.0 software. These desirability profiles show which levels of predictor  variants, called primary form (1°) and secondary form (2°). Only 1° exhibits a considerable antibiotic activity [X. bovienii YL002 was maintained on nutrient agar (NA) slants and subcultured monthly. The primary-secondary switch is spontaneous and in case of X. bovienii is irreversible. Consequently the laboratory cultures should be scored after recovering from the 20% glycerol suspension in which they had been stored in the deep freezer. To ensure the predominance of 1° population, refrozen cells were seeded on the surface of NA media supplemented with 0.04% triphenyltetrazolium chloride (w/v) and 0.025% bromothymol blue (w/v) (NBTA), and fresh liquid culture were started from single blue (1°) colonies as described [eristics ,37. The activity . X. boviescribed .X. bovienii YL002 from a 72 h culture growing on an NBTA plate into a 250 mL flask containing 50 mL fresh YSG medium 2SO4 2 g/L, 1 M KH2OP4 5 mL, 1 M K2HOP4 5 mL and 1 M Na2SO4 10 mL) [X. bovienii YL002. The flasks were incubated in the dark at 28°C on an Eberbach rotary shaker at 150 rpm for 18-24 h until the optical density (600 nm) and pH readings were approximately 2.0 and 7.0, respectively.Seed culture for antibiotic production was prepared by inoculating a loopful of phase I 4 10 mL) , which wBacillus subtilis[7-108 colonies of B. subtilis was applied to NA plate. After 2 h incubation at room temperature, the supernatants of culture following microfilteration (100 μL), using a 0.22 μm syringe microfilter, were placed on 6-mm disk filters (Whatman 3-mm paper) and air dried. The dried disks were put on the NA plate and incubated at 28°C for 24 h to determine the relationship between the size of the zones of inhibited bacterial growth and the concentration of the antibiotic. Zones of inhibition were measured, and measurements were taken from the edge of antibiotic disk to the margin of the zone of inhibition. Antibiotic activity was expressed as units of activity per milliliter the supernatants of culture, where 1 U was defined as a 1.0 mm annular clearing around the antibiotic disk.Antibiotic activity was measured by agar diffusion plate assay with  subtilis. BrieflyX. bovienii by homogenizing the insects in distilled water [X. nematophila YL001 [X. bovienii YL002.Maxwell et al. confirmed the assumption that the changes in the size of the zones of inhibition (expressed as units of activity per gram of insect tissue) represented changes in antibiotic concentration; the antibiotics were extracted from insect larvae killed by ed water . The assla YL001 . TherefoCell growth was measured by optical density of the culture at 600 nm and biomass concentrations (DCW: g/L) were determined using a calibration curve. The calibration curve was calculated using dilutions of a biomass suspension with known optical density. A fixed volume of the dilutions was centrifuged  and drying of the cell pellets at 110°C for 24 h. All the cell pellets were weighed before the centrifugation and after the drying. Thus, a relationship between biomass concentration (g/L) and optical density (600 nm) can be determined.4)2SO4 5 g/L, MgSO4·7H2O 0.2 g/L, KH2PO4 0.5 g/L, K2HPO4 0.5 g/L), TSB  and YSG were used in comparative studies to find the optimal nutrient medium for antibiotic production. Five microlitter of the seed culture was transferred into 50 mL of different sterile medium in 500 mL flask. The flasks were incubated in the dark at 25°C on an rotary shaker at 150 rpm. Samples of ca. 3 mL were withdrawn each 6 h approximately. An amount of 1 mL aliquots of the fermentation broth were centrifuged  to separate the bacteria cells from the supernatants. The supernatants were store at 4°C until required for use.Different media such as nutrient broth, modified nutrient broth , PP3 broth (proteose peptone 20 g/L), modified PP3 broth , LB , YS broth , soytone (X2) and minerals (X3) defined as the total concentration of the minerals of YSG medium and kept the proportion of diversified components. According to the central composite design, the total number of experimental combinations is 2k + 2k + n0, where k is the number of independent variables and n0 is the number of repetitions of the experiments at the centre point [Xi have been coded as xi according to the following transformation equation:The response surface methods by using a set of experimental design  were used to optimize the constituents of antibiotic production. The selected independent variables of the medium components were glycerol  was fitted by a second order model in order to correlate the response variable to the independent variables. The general form of the second degree polynomial equation iswhere Y is the measured response, 0 isβ the intercept term, iβ , ijβ, and iiβ are the measures of the effects of variables ix, ixjx , and x2i, respectively. The variable ixjx represents the first-order interaction between ix and jx (i <j).where 3-factorial experimental design (CCD) for three independent variables each at five levels with four axial points and six replicates at the center points leading to a total number of twenty experiments was employed for the optimization of the medium constituents. The STATISTICA 8.0 software  was used for regression and graphical analyses of the data obtained. The response variable was assigned at low and high of the observed values for a desirability of 0 and 1, respectively, to get the overall desirability. The desirability function to get the optimum combinations of independent variables was fitted by the least square method using the software. The 3D response graph and profile for predicted values and desirability level for factors were plotted using the same software.For the medium constituent optimization, a 2F-test , its associated probability P(F), correlation coefficient R, and determination coefficient R2 that measures the goodness of fit of regression model. The analysis also included the Student's t-value for the estimated coefficients and associated probabilities, P(t). For each variable, the quadratic models were represented as contour plots.The statistical analysis of the model was performed in the form of analysis of variance (ANOVA). This analysis included the Fisher's The authors declares that they have no competing interest.YW conceived, designed and organized the study. XF conducted the data analysis. YW and XF conducted the interpretation of results and drafted the manuscript. YW and XF contributed equally to this work as first authors. FA and GW carried out the experiments. XZ participated in critical reviews and improvement of the manuscript. All authors have read and approved the final manuscript.This work was supported by the Natural Science Foundation of China (No. 31171910), National Department Public Benefit Research Foundation of China (No. 200903052) and Young People Science Program of Northwest A & F University (No. 52211241).


New findings from two Gates Foundation–supported studies—the Global Enteric Multicenter Study and the Global Burden of Disease Study 2010—suggest the possible importance of adding coverage for intestinal protozoan infections as part of World Health Organization preventive chemotherapy initiatives.In 2011, the World Health Organization (WHO) determined that more than 700 million people were treated with at least one essential medicine for neglected tropical diseases (NTDs) under the auspices of a global preventive chemotherapy initiative The original “rapid-impact” package of NTD interventions targeted up to seven NTDs highly endemic to sub-Saharan Africa, including the three soil-transmitted helminthiases, schistosomiasis, lymphatic filariasis, onchocerciasis, and trachoma, and was comprised of up to four essential NTD medicines that could include a benzimidazole anthelminthic drug , ivermectin, praziquantel, and/or azithromycin As global preventive chemotherapy efforts expanded, it also became apparent that they could produce important collateral public health benefits that were not originally anticipated, including overall reductions in child mortality from the azithromycin component In the last year, two important studies were published that could alter how we think about current preventive chemotherapy approaches. The first, known as the Global Enteric Multicenter Study (GEMS) for diarrheal diseases, made the surprising finding that cryptosporidiosis is one of the most important causes of infectious diarrhea in children in developing countries A potential candidate drug for use in mass drug administration programs to target intestinal protozoa is the nitrothiazole benzamide drug, nitazoxanide  [17]. ThEntamoeba histolytica and could be used to treat both invasive intestinal amoebiasis and colonization with E. histolyticaHymenolepis nanaClostridium dificileAlthough the initial indication for nitazoxanide was for cryptosporidiosis and giardiasis, subsequent investigative research has revealed that the drug is effective for amoebiasis caused by Because of its broad-spectrum activity against a variety of intestinal pathogens, there has been interest in evaluating nitazoxanide as a potential agent for public health control. Among Mexican children, the drug showed promise for reducing the burden of a variety of intestinal parasites Cryptosporidium partum or E. histolytica, especially in field conditions in a highly disease-endemic country of Africa or Asia.The possibility of adding nitazoxanide to current regimens used for WHO preventive chemotherapy initiatives as a means to broaden coverage against intestinal protozoa and possibly other pathogens has the potential of significantly increasing preventive chemotherapy's impact on reducing global disease burdens of parasitic infections and NTDs. However, to even consider adding nitazoxanide, there are quite a few operational research questions that would need to be addressed. Among them is that most likely nitazoxanide would need to be administered alongside other NTD drugs in the rapid-impact package as an annual single dose. It is unclear whether a single dose of 500 mg of the drug, or even a 1 g dose as used in a trichuriasis field study in Pemba, Tanzania Another important issue is selecting the optimal targeted age group. According to the GEMS study, cryptosporidiosis has its most important impact on preschool children, especially children under the age of two Added concerns are the drug compatibilities and, of course, the safety and efficacy of co-administering NTD medicines with nitazoxanide. There is also the issue of cost—could nitazoxanide join other essential NTD medicines as a donated drug? Certainly the impact of providing nitazoxanide in programs of mass drug administration must also be further evaluated for the potential to promote drug resistance.Such aspects would have to be carefully addressed in well-conducted and supervised programs of operational research in appropriately resource-poor settings. However, the potential benefits of adding cryptosporidiosis and amoebiasis targets to current preventive chemotherapy regimens may be sufficiently important to warrant next steps in evaluating nitazoxanide in this context.


Acknowledgment of all serious limitations to research evidence is important for patient care and scientific progress. Formal research on how biomedical authors acknowledge limitations is scarce.hedges; to assess the association between industry support and the extent of hedging.To assess the extent to which limitations are acknowledged in biomedical publications explicitly, and implicitly by investigating the use of phrases that express uncertainty, so-called We analyzed reporting of limitations and use of hedges in 300 biomedical publications published in 30 high and medium -ranked journals in 2007. Hedges were assessed using linguistic software that assigned weights between 1 and 5 to each expression of uncertainty.Twenty-seven percent of publications (81/300) did not mention any limitations, while 73% acknowledged a median of 3 (range 1–8) limitations. Five percent mentioned a limitation in the abstract. After controlling for confounders, publications on industry-supported studies used significantly fewer hedges than publications not so supported (p = 0.028).Detection and classification of limitations was – to some extent – subjective. The weighting scheme used by the hedging detection software has subjective elements.Reporting of limitations in biomedical publications is probably very incomplete. Transparent reporting of limitations may protect clinicians and guideline committees against overly confident beliefs and decisions and support scientific progress through better design, conduct or analysis of new studies. Peer review has been defined as a “negotiation between author and journal about the scope of the knowledge claims that will ultimately appear in print” The recognition that scientific papers often try to convince or influence readers Fletcher and Black discussing several ways in which “spin” occurs in the medical literature suggested that editors be more vigilant with industry-sponsored studies explicitly, through an analysis of limitations sections, and implicitly, through linguistic analysis of the phrases used to moderate the strength of claims, also called “hedges” In this contribution, we studied how limitations are presented in biomedical research publications: In sub-study 1 we assessed (i) in what proportion of publications limitations are acknowledged, (ii) what types of limitations are discussed and (iii) in what manner, and (iv) whether the uncertainty arising from acknowledged limitations is reflected in the sections on implications for practice and conclusions. In sub-study 2 we analyzed the amount of uncertainty that is expressed and if that amount differed between journals, and industry-sponsored and other research in particular.st through 5th); the other half ranked 11th through 15th, according to journal impact factors (ISI 2007). Using a structured assessment form , observational or diagnostic studies published in 2007. Within the group of medical and specialty journals, half were top journals . Results are reported using descriptive statistics. Logistic regression analysis was used to explore whether general medical and top ranking journals have different rates of acknowledged limitations than specialty journals.may, could), adverbs , and lexical verbs  are detected, and each hedge is given a score between one and five, with higher scores reflecting more uncertainty To determine hedging patterns, we used a software programme Clinical Gastroenterology and Hepatology were missed in the transfer from our epidemiology team  to the linguistic team that assessed the hedges  due to an administrative error that we detected only at the analysis stage. For six papers, the software program used to determine hedging patterns could not read the pdfs necessary to determine the hedging score.The variable that coded for study quality was assigned the label ‘good (1)’ if at least one criterion applied, and as ‘less than good (0)’ otherwise, where randomized trials had to have concealment of randomization and/or proper random sequence generation, while observational studies were assessed for adjustment of confounding of the main association. Finally, the sample size was categorized in 6 categories using as cut-offs: 50; 100; 300; 1,000; 10,000. All data were extracted by one reviewer and checked for errors by another reviewer. Discrepancies were resolved through consensus. Three hundred publications were potentially eligible to measure the extent of hedging. We finally included 284 papers in the analyses of hedges. The ten papers from the journal all measured confounders. In all analyses we added variables to represent each of the 29 journals and controlled for any journal effect. The New England Journal of Medicine (NEJM) served as the reference category For the sub-study on the hedging scores, we did not perform a sample size calculation, since we wanted to include as many of the papers from sub-study 1 as possible. We performed four multivariable linear regression analyses: two with the normalized hedging score, and two with the number of author-acknowledged limitations as the dependent variable, respectively vs rank 11–15) did not affect these estimates.Eighty-one of the 300 publications did not acknowledge any limitation . Two hundred nineteen publications acknowledged a median of 3 (range 1–8) limitations in the discussion section , whereas 16 acknowledged a limitation in the abstract . 186/300  of acknowledged limitations referred to aspects of internal validity, mostly to measurement errors (n = 149). 114/300  of acknowledged limitations referred to aspects of external validity, mostly to selected study populations (n = 115). 183/219 of the publications did not temper the conclusions because of limitations . Publications in general medical journals were more likely to acknowledge limitations than publications in specialty journals , particularly in abstracts . Conclusions were not tempered more frequently in general medical journals. . Journals' tier (rank 1–5 th centile) to 4,471 (75th centile) words. There were 61 (21.5%) industry-supported publications by our criteria. Papers published in the British Journal of Psychiatry, the British Medical Journal and the Annals of Family Medicine used around 1.5 to 2 more hedges per 100 words than the NEJM. The publications from the Annals of Surgical Oncology acknowledged 2.18 fewer, Medicine 2.61 fewer, those from the American Journal of Medicine 1.58 more, Annals of Internal Medicine 1.73, and Chest 2.90 more limitations than those from the NEJM.The results from the two sensitivity analyses were slightly less conservative than the results from the primary analyses presented here (data available on request).We found that over a quarter of biomedical publications do not discuss any limitations. In abstracts, limitations are rarely mentioned. Industry-supported publications appear to express less uncertainty after controlling for factors that justify confidence in the study results. Finally, we found major differences between journals in how uncertainty is expressed and limitations acknowledged.plan a flawless study than to execute one. This distinction is important since readers can increasingly read the investigators' intentions through, for example, trial registration websites or separate publications dealing solely with a study's rationale, design and protocol details Complete reporting of study design, success of execution and, if appropriate, statistical analysis give meaning to the results of empirical studies. That is why, in science, we value (detailed) methods sections in research publications Obviously, the present work would be quite incomplete if we did not address its limitations. First, for sub-study 1, the body of papers we assessed is five years old. However, we think that is unlikely that the awareness about acknowledging limitations has changed much, if at all, in recent years. Second, in sub-study 2, we lost 10, and could not analyze six of our 300 publication sample due to administrative errors or technical problems. Third, the software application used to calculate the hedging scores was not perfect. In particular, its accuracy is only about 93% As far as we are aware, research on the use of limitations is scarce. Previously, Ioannidis reported that 17% of publications mentioned any limitations. However, he used an automated search strategy on the texts that is likely to have missed acknowledgments of limitations Although the STROBE statement encourages authors to “Discuss limitations [..], taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias”, “Give a cautious overall interpretation of results considering objectives, limitations, [..] etc.” and the CONSORT statement urges authors to address “Trial limitations, addressing sources of potential bias, imprecision, and, if relevant, multiplicity of analyses.” Replication of this work is needed. Our work may be improved by calculating hedging scores per section. Sensitivity analyses with the hedging-weights may shed light on the role of the weights assignment in the hedging software. Some of the ideas we suggested above may be carried out as research projects at the editorial offices. For example, we may try to assess if more structured approaches are implementable, what the challenges involved are with such approaches, and what effects can be measured after implementation on for example transparent reporting, time investment needed, authors avoiding journals with a strict approach in place, and effects on journals' impact factors. Long-term effects may involve the quality of clinical practice guidelines and patient care and its outcomes. And finally, larger studies may try to replicate and investigate in depth how by-journal hedging score variation is related to editorial policies.In conclusion, our data show that reporting of limitations to original biomedical research is probably incomplete. Either directly, through clinical decision-making by evidence-based clinicians or indirectly through its effects on systematic reviews and clinical guidelines, optimal patient care may be jeopardized. Finally, scientific progress may be slowed down: reporting limitations more completely would aid the design and implementation of future studies. An appropriate amount of hedging given these limitations could further guide future scientific inquiry.Appendix S1Data extraction form for sub-study 1 (n = 300).(DOC)Click here for additional data file.


IgG4-related lung disease is commonly associated with autoimmune pancreatitis. Recently, isolated IgG4-related interstitial lung disease (ILD) without other organ involvement has newly been reported in two cases with clinical features of nonspecific interstitial pneumonitis (NSIP).We report the first case of an isolated IgG4-related ILD in a 78-year-old man with dry cough and dyspnea, whose clinical findings proved to be different from NSIP. Serum IgG4 levels were increased. Chest CT scan revealed bilateral consolidations especially in the lower lobes, enlarged mediastinal and hilar lymph nodes and pleural effusions. Video-assisted thoracoscopic (VATS) lung biopsy revealed a pattern similar to usual interstitial pneumonia (UIP) and an abundant IgG4-positive plasma cell infiltration. He was effectively treated by steroid therapy.Increasing recognition of IgG4 related diseases has led to a growing number of new entities. The novel concept of isolated IgG4-related ILD as a pulmonary manifestation of a systemic IgG4-related disorder should be taken into account as a possible differential diagnosis of ILD and mass-forming lesions, even when no other organ manifestation is clinically apparent at the time of diagnosis. Lung specific diagnostic criteria and algorithms are required to enhance diagnostic accuracy in cases of possible IgG4-related ILD. IgG4-related disease (IgG4-RD) is a recently discovered systemic sclerosing disease that is characterized by IgG4-positive plasma cell and T-lymphocyte infiltration of various organs and elevated serum IgG4 concentrations in the majority of patients ,2. TissuEffective treatment is needed when vital organs are affected because IgG4-RD can lead to serious organ damage . Both thIn recent years, IgG4-related interstitial lung disease (ILD) has newly been reported, occurring with and without other organ involvement .A 78-year-old man with no significant past medical history presented with a 9 months history of dry cough and shortness of breath upon exertion. He had a short-term history of occupational inhalation of nitro-cellulose in a paint-spray line in 1961, but no history of smoking and no regular drug intake. Physical examination revealed decreased breath sounds and bilateral inspiratory fine crackles in the lower zones. Pulmonary function test demonstrated a restrictive pattern with mildly reduced diffusing capacity (DLCO).Chest CT showed bilateral, pleural consolidations of the lower and upper lobes with air bronchograms, diffuse ground-glass opacities and traction bronchiectasis, enlarged mediastinal and bilateral hilar lymph nodes, small bilateral pleural effusions and a small pleuropericardial callus on the left side.Laboratory findings showed increased serum levels of IgG  and IgG4 . Anti-nuclear antibody level was positive  and complement components C3c and C4 were decreased . Eosinophil count was increased to 0.38 Giga/l (5.6%).Bronchoalveolar lavage Giemsa stain was not evaluable due to mucus and predominantly destroyed cells.Pathological examination of a surgical lung biopsy obtained by video-assisted thoracoscopic surgery (VATS) revealed a pattern similar to UIP with chronic lymphoplasmacytic infiltration and significant diffuse interstitial and pleural fibrosis of both reticular, confluent and mass-like aspect, as well as moderate honeycomb changes and significant vascular wall thickening. There was no evidence of vasculitis.Immunostaining showed infiltration in the interstitium of CD3 positive T-cells and CD20 positive B-cells as well as numerous CD38 positive, IgG4-positive plasma cells. The mean number of IgG4+ plasma cells per high power field (HPF) was more than 10.Bone marrow aspiration and peripheral blood flow cytometry did not demonstrate a monoclonal lymphoid population nor suggest malignancy.Based on our findings, a final diagnosis of isolated IgG4-related ILD was made. 4 months after initiating a treatment with prednisolone (60 mg/day), the patient showed improvement of symptoms and there was a normalization of IgG4 levels . Chest x-ray and chest CT Figure  as well The first case of ILD associated with IgG4-related disease was reported in 2004 in a 63-year-old man with AIP . In westIn 2008, Takato et al. reported the first case of isolated IgG4-related ILD in a 59-year-old man who was found to have ground-glass opacities and reticular shadows with honeycomb-like changes and traction bronchiectasis in the lower lobes on chest CT scan. Pathological examination of a lung biopsy obtained by VATS revealed findings corresponding to fibrotic nonspecific interstitial pneumonitis (NSIP). Subsequent immunostaining for IgG4 showed infiltration with numerous IgG4-positive plasma cells. Serum IgG4 levels were increased. This patient did not present with AIP and the authors suggested that IgG4-related ILD could occur unrelated to AIP [More recently, another case of isolated IgG4-related interstitial pneumonia was reported in a 75-year-old male patient who presented with a two months history of cough and shortness of breath upon exertion. A chest CT scan revealed bilateral diffuse ground-glass opacity with traction bronchiectasis, especially in the bilateral lower lobes. Serum IgG4 levels, which were screened by chance, were increased. Pathologic examination of VATS biopsies revealed infiltration of mostly IgG4 positive plasma cells. There was thickening of the bronchovascular bundles and alveolar septa but neither fibrotic nor vascular lesions were observed. The authors hypothesized that IgG4 plays an important role in the pathogenesis of some cases of interstitial pneumonia initially diagnosed as idiopathic NSIP, and that these interstitial pneumonias may be regarded as a new entity that should be differentiated from idiopathic NSIP .The present case, to our knowledge, is the third case of isolated IgG4-related ILD ever reported and the first observed in western countries. Similar to the cases reported before ,6, AIP wAlthough a histological finding of UIP often corresponds to a clinical diagnosis of idiopathic pulmonary fibrosis (IPF), it is known that a histological pattern similar to UIP, like in the present case, can also occur in clinical conditions other than IPF . In factClassification criteria and nomenclature of IgG4-RD are currently being established . We doubComprehensive diagnostic criteria for IgG4-RD have recently been proposed, including additional organ specific criteria for IgG4+ AIP, renal and Mikulicz’s disease . HoweverWritten informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.AIP: Autoimmune pancreatitis; CT: Computed tomography; DLCO: Diffusing capacity of the lung for carbon monoxide; DPLD: Diffuse parenchymal lung disease; HPF: High power field; IgG: Immunoglobulin G; IgG4: Immunoglobulin G subclass 4; ILD: Interstitial lung disease; NSIP: Non-specific interstitial pneumonia; UIP: Usual interstitial pneumonia; VATS: Video-assisted thoracoscopy surgery.The authors declare that they have no competing interests.TW carried out the literature review, coordination and draft of the manuscript. CK, SR, IB, KS participated in drafting the manuscript and revising it critically. WR and CS have participated in revising the manuscript and have given final approval of the version to be published. All authors read and approved the final manuscript.


With ageing of the HIV-infected population, long-term exposure to treatment, varying adherence, emerging resistance and complications to therapies, effectiveness of Highly Active Antiretroviral Therapy (HAART) needs to be monitored continuously at the population level. The German HIV-1 Seroconverter Cohort is a multi-centre, open, long-term observational cohort including patients with a known or reliably estimated date of HIV-infection i.e. last negative and first positive HIV antibody test within a maximum three-year interval or laboratory evidence of seroconversion. Our study aims to investigate survival improvements and changes in AIDS risk over calendar periods in the German HIV-1 Seroconverter Cohort.Retrospective (for the pre-1997 period) and prospective (since 1997) data from the German HIV-1 Seroconverter Cohort were used. Time from seroconversion to first AIDS-defining event over calendar periods was analysed by using Cox models adjusting for age at seroconversion, sex, transmission groups and short HIV test interval. Kaplan-Meier methods were used to determine expected survival (remaining AIDS-free) by calendar period.2162 seroconverters with 8976 person-years of observation were included in our analysis (up to 31.12.2010). A total of 196 first AIDSdefining events were reported. Two periods i.e. 19972000 and 2007-2010 were statistically associated with a reduction in the risk of AIDS, accounting for an overall reduction of 80%. Compared to1997-2000, hazard ratios were 2.6  in pre-1997 and 0.5  in 20072010. Independent risk factor for AIDS progression was age at seroconversion .HAART effectiveness has improved in the German HIV-1-Seroconverter Cohort. The risk to develop AIDS decreased significantly in 19972000 and in 20072010. However, elderly may require particular monitoring in view of their faster progression to AIDS. Long-term observational studies with reliable HIV-1 seroconversion dates are a good tool to assess the effectiveness of highly active antiretroviral therapy (HAART) at the population level . Just afIn Germany, HIV surveillance is regulated by the national Protection against Infection Act since 2001 . Newly dThis paper aims to present the results of the German HIV-1 Seroconverter study, covering more than 13years of surveillance, in order to monitor at the population level the progression to AIDS and associated risk factors over calendar periods.The German HIV-1 Seroconverter study started in 1997 as a national multicenter observational cohort study including HIV-infected persons for whom the date of seroconversion is known or could reliably be estimated. Study participants are recruited by more than 22 outpatient clinical centres, 40 medical practices specialised on HIV/AIDS and seven local health authorities all over Germany, mainly in German metropoles. All HIV infected patients aged 18years or older (at the time of study enrolment) are eligible to be included in the cohort if their date of seroconversion can be reliably estimated, either as acute or as documented seroconverters, which has been described in detail elsewhere . BrieflyOn the basis of a baseline standardized paper-based questionnaire, demographic , clinical (including CDC-status and current therapy regimes) and laboratory data  are collected by physicians. Yearly follow-up questionnaires include CDC-status and current therapy regimes. Questionnaires are sent to the RKI where they are reviewed and integrated in the HIV database, and checked for completeness and plausibility. If data inconsistencies cannot be resolved, the institutions are queried.We analysed the time from seroconversion to AIDS via Cox proportional hazard model, a method that allows for late entry and inclusion of retrospectively ascertained seroconversion . Since tIndividuals were censored either by the day of the last medical visit or by the date of the first AIDS-defining event, defined in accordance with clinical criteria from the 1993 Centers for Disease Control and Prevention (CDC) case definition . IndividAdjustment was done for sex, HIV exposure category, age at seroconversion and short HIV test interval . HIV exposure categories included, in the following order of priority: injecting drug users (IDU), men who have sex with men (MSM), heterosexuals, other , and unknown. Among heterosexuals, a new group including people originated from high prevalence countries (HPC) was created. To investigate whether the effects of these determinants changed over time, we included interaction terms between each determinant and the calendar periods at risk. Interaction was tested using likelihood ratio tests. Kaplan-Meier methods were used to determine the expected survival probability (remaining AIDS-free) in each calendar period and Log-rank tests for equality of survivor functions. All p-values are two-sided, and a p-value of 0.05 or less was considered significant. All data were analysed using STATA 11.0 .The Seroconverter study was approved by the local ethics committee of the Charit  in Berlin and reconfirmed in 2010. Informed consent was obtained for each participant of the study.By the end of 2010, a total of 2162 eligible patients were enrolled in the study and included in the analysis. Of these, 214 patients were retrospectively included, namely having a date of seroconversion before 1997. Both the number of included patients and follow-up increased largely after 2001, when the study was better established. The overall median age at seroconversion was 33years (IQR: 2739) without major changes over calendar periods (Table Over the 8906 person-years (PY) of follow up , 196 first AIDS-defining events were reported, leading to an overall AIDS incidence rate of 2.2 per 100 PY . The AIDS incidence rate per 100 PY decreased significantly from 6.9 in pre-1997  to 2.6  in 19972000, 1.9  in 20012004, 3.7  in 20052006 and 1.3  in 20072010 (Table The proportion of patients developing AIDS within 2 and 10years decreased significantly (p=0.0001) from 14% and 50% in pre-1997 to 4% and 33% in 19972000, respectively , from 0.6 per 100 PY in 19972000 to 0.3 per 100 PY in the following periods. The lost to follow up rate was also relatively stable over the calendar periods, except for the pre-1997 period where it was lower (0.4 per 100 PY)  in pre-1997 and 0.5  in 20072010 . Compared to the group of MSM, the risks among people originating from HPC and IDU were not significantly increased, with HR of 2.3  and 1.4 , respectively. Heterosexual transmission had a similar risk as compared with homosexual male transmission .To investigate whether the prognostic effects of these covariates had changed over time, we included interactions between calendar period and each of the covariates in the Cox model. To reduce model instability, we collapsed the calendar periods to pre-1997, 19972006 and 20072010, and excluded 9 patients with occupational exposure and 36 with unknown exposure. There was no evidence of a change over time in the effect of age (p=0.1287) although we noticed a decrease in the HR from 1.6 to 1.0 over the calendar periods , 0.5-2.8years]. The temporal trend of this median showed first a decrease from 1.6 in pre-1997 to 0.8 and 0.4years in 19972000 and 20012004 respectively, followed by an increase to 1.4 and 1.9years in 20052006 and 20072010 respectively. More precisely, this trend was confirmed when analysing proportions of person-years spent on treatment over total follow-up time, stratified by calendar period and categorised by the proportion initiating treatment within 2years, between 2 and 5years, and more than 5years . We found an overall reduction of 80% in the risk of AIDS over the calendar periods, which was not linear but included two main drops, one after 1997 and one after 2007. This is the first study to our knowledge showing a reduction in AIDS risk after 2007. However, these results might be influenced by the fact that the study population includes a large proportion of MSM who are more likely to be closely monitored by HIV specialists and may therefore not be representative of the entire German population infected by HIV. A similar cohort study in Spain reported significant reduction in the risk of AIDS over calendar periods in comparison with the pre-HAART era, but there were no differences between the calendar periods in the post-HAART era .Our results showed an overall increase in HAART uptake, which likely parallels the decrease in AIDS risk. These trends have also been seen in the UK, where the proportion of patients being treated by antiretroviral therapy increased from less than 2% in pre-1996 to 58% in 20042006 . The decWe observed a trend towards initiating treatment later following seroconversion in later calendar periods. This could be explained by the different recommendations in Germany since 1997. Following the Vancouver Conference  and the The main determinant that affects disease progression in our cohort was age at seroconversion. This factor, together with duration of infection, was already known to be a crucial determinant of HIV disease progression in developed countries before the introduction of HAART . HoweverOur results did not show an effect of sex on AIDS risk. This result contrasts with recent studies that reported a slower disease progression among women than men ,18. HoweComparing disease progression rates between transmission risk groups in our study was difficult, considering the large proportion of MSM compared to the other transmission groups. However, the trend over the calendar periods showed that IDU had a smaller reduction in AIDS risk as compared with the others risk groups. This result is supported by Porter et al., reporting a smaller reduction in AIDS risk in the post- HAART era among IDU . HoweverThe presence of seroconversion illness, typically characterized by flu-like symptoms, has been reported to be associated with a more rapid disease progression ,21. In oThis studys principal strength is its good quality data on date of seroconversion, permitting reliable approximation of AIDS incidence and risk. This study also has the advantage of providing data for more than 13years of prospective follow-up from different settings, representing roughly 10% of all new HIV diagnoses reported to the national HIV surveillance since 2004. However, some limitations have to be raised. First, the data for the pre-1997 period are retrospective and may not be as reliable as the data from the prospective period. Patients in this period were included regardless of their AIDS outcome; a survivorship bias might have been introduced as patients have to sign an informed consent at study entry. Regarding the pre-AIDS mortality, this bias might have been limited as the pre-AIDS mortality rates were relatively stable and at a very low level during the prospective periods. Regarding the lost to follow up, rates were relatively stable over the time periods but were at a high level. If lost to follow up subjects have a more rapid progression, the pre-1997 period in our study might underestimate the risk of AIDS in comparison to the other periods but our results remain conservative to this regard. Alternatively, we might have overestimate the first decrease in the AIDS risk if lost to follow up subjects have a slower disease progression. Considering only the periods after 1997, a bias might have been introduced if lost of follow up subjects differ between the periods. Further analyses  should be performed to better answer that issue. Another issue is that women are largely underrepresented in this study (6.2%) in comparison with the national reporting system, in which women accounted for as many as 20% of all new diagnoses between 1997 and 2010. This proportion does not allow us to analyze the effects of sex and HIV transmission categories with enough power. Finally, we assumed continuous HAART intake after treatment initiation. This limitation might be important for the interpretation of the proportion of people being treated by calendar period. However, this does not change the interpretation of the effectiveness over time. The treatment was considered to be HAART  in every calendar period from 1997 onwards, even if this might not be the case for one or two percent.HAART effectiveness has improved in the German HIV-1-Seroconverter Cohort. After a main reduction in the risk of AIDS in 19972000, a second significant decrease occurred in 20072010. However, elderly may require particular monitoring in view of their faster progression to AIDS.AIDS: Acquired immunodeficiency syndrome; CDC: Centres for Disease Control and Prevention; HAART: Highly Active Anti Retroviral Therapy; HPC: People from high HIV prevalence countries; HR: Hazard ratio; IDU: Injecting drug users; IQR: Interquartile Range; MSM: Men who have sex with men; NRTI: Nucleoside reverse transcriptase inhibitor; NNRT: Non- nucleoside reverse transcriptase inhibitor; PI: Protease inhibitor.The authors declare that they have no competing interests.All authors were involved in asking the research question presented in this manuscript. MA was responsible for statistical analyses together with MadH. MA wrote the first draft of the paper. All authors reviewed the final manuscript.The German HIV-1 Seroconverter Cohort is funded by the German Ministry of Health.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2334/12/94/prepub


Ecorr and concrete resistivity ρ in each point of the applied grid were measured. The experimental results indicate that the proposed methodology can be successfully used to assess the probability of corrosion in concrete structures.In recent years, the corrosion of steel reinforcement has become a major problem in the construction industry. Therefore, much attention has been given to developing methods of predicting the service life of reinforced concrete structures. The progress of corrosion cannot be visually assessed until a crack or a delamination appears. The corrosion process can be tracked using several electrochemical techniques. Most commonly the half-cell potential measurement technique is used for this purpose. However, it is generally accepted that it should be supplemented with other techniques. Hence, a methodology for assessing the probability of corrosion in concrete slabs by means of a combination of two methods, that is, the half-cell potential method and the concrete resistivity method, is proposed. An assessment of the probability of corrosion in reinforced concrete structures carried out using the proposed methodology is presented. 200 mm thick 750 mm  ×  750 mm reinforced concrete slab specimens were investigated. Potential  Corrosion of the steel reinforcement in concrete is a crucial problem for the construction industry since it poses the most serious risk to the structural integrity of reinforced concrete structures. Inspection and monitoring techniques are needed to assess the corrosion of the reinforcement in order to maintain, protect, and repair buildings and bridge decks so that they remain safe , 2. In tin situ corrosion testing is the half-cell potential measurement, the idea of which is illustrated in Several electrochemical techniques for monitoring and assessing the corrosion of steel in concrete structures were presented in –7. The mρ ranges widely from 101 to 106 Ω m, depending on mainly the moisture content [ρ is inversely proportional to the corrosion rate. This was confirmed by Glass et al. [ρ and corrosion rate. The four-point resistivity method enables one to determine the severity of corrosion in a quick and nondestructive manner. Morris et al. [ρ is below 10 kΩcm, whereas at concrete resistivity ρ above 30 kΩcm the probability of their corrosion is low. Extensive research on the resistivity technique, covering experimental analyses [It is well known that the probability of corrosion in concrete structures depends on the ionic conductivity of the concrete electrolyte, the humidity, the temperature, and the quality of the concrete cover. The ionic conductivity is measured quantitatively as the resistivity of the concrete . Concret content  and the  content , 20. One content , concrets et al.  who shows et al.  showed ts et al.  found thanalyses  and an aanalyses , was donρ in the same locations where half-cell potentials were measured, but it should be noted that the measurements were carried out on a concrete bridge deck covered with asphalt.It should be noted that in the literature there are only a few papers in which the probability of corrosion is determined using both concrete resistivity measurements and half-cell potential mapping. One of them is the paper by Millard and Sadowski  in whichConsidering that in the literature it is hard to find a systematic methodology for assessing the probability of corrosion in concrete slabs through combined half-cell potential and concrete resistivity measurements, this paper proposes such a methodology based on the combined use of the four-point Wenner concrete resistivity method and the half-cell potential method.The proposed methodology for assessing the probability of corrosion in concrete slabs through a combination of two methods, that is, the half-cell potential method and the concrete resistivity method, is illustrated graphically in n measuring points spaced at every 75 mm should be marked on the slab surface. Then the electrical continuity of the reinforcement is checked in three randomly selected grid points. Subsequently potential Ecorr and concrete resistivity ρ are measured. If the results of the Ecorr and ρ measurements are satisfactory, they are processed using the specialized software and maps of the distribution of the parameter values on the slab surface are produced. The distribution maps of potential Ecorr and concrete resistivity ρ should be examined. ρ and potential Ecorr measurements, three areas of different types can be generated:area type 1—low values of both parameters, greater than 90% probability that reinforcing steel corrosion is occurring in that area at the time of measurement;ρ and high values of measured potential Ecorr, an uncertain probability of corrosion;area type 2—low values of concrete resistivity area type 3—high values of both parameters, a 10% probability of corrosion.Before measurements, the surface of the concrete slab should be prepared by brushing and polishing with abrasive paper, and a grid of Finally, a contour plot of three types of areas  should be generated.The corrosion probability assessment can be practically verified through test pits made in selected places and visual inspection . An exemplary application of the proposed methodology is presented below. 200 mm thick 750 mm × 750 mm concrete slab specimen was investigated . The conMeasurements were carried out after 90 days of concrete curing, except for compressive strength tests which were done after 28 days. The concrete slabs cured at an air temperature of +18°C (±3°C) and a relative air humidity of 60%. It is important to measure concrete resistivity in constant temperature-humidity conditions since, as shown in , with eaPrior to half-cell potential measurements, the electrical continuity of the reinforcement was checked at three randomly selected grid points. The potential differences in the three points were measured with a digital voltmeter, and all the measured values were found to be below 1 mV. The copper/copper sulphate electrode used in this test is shown in ρ was measured in each point of the grid  in the area around measuring points 7 to 9 from E to I, which indicates a 95% probability of corrosion. In the other measuring points, potential Ecorr is high (−350 mV ≤ Ecorr ≤ −200 mV), which indicates a 10% or uncertain probability of corrosion.Exemplary results of the half-cell potential measurements are shown in ρ is low (<5 kΩcm) in the area around measuring points 5 to 9 from A to I, which indicates a very high probability of corrosion. In the other measuring points, concrete resistivity ρ is high (>5 kΩcm), indicating a high or moderate probability of corrosion. The results of the concrete resistivity measurements are shown in Ecorr ranging from −432 to −144 mV. The average value of potential Ecorr was −211.09 mV with standard deviation of 53.46 mV. Selected statistical characteristics of the parameters determined by half-cell potential and concrete resistivity measurements are shown in ρ determined by concrete resistivity measurements ranged from 3.14 to 9.99 kΩcm. The average value of concrete resistivity ρ was 5.68 kΩcm with standard deviation of 1.66 kΩcm. Concrete resistivity ρ and potential Ecorr, measured on the concrete slab surface, is shown in Ecorr sharply increases for resistivity ρ below 4 kΩcm while above 4 kΩcm, it oscillates between −150 and −250 mV.The dependence between concrete resistivity ρ and potential Ecorr measurements, three areas of different types were generated (Ecorr is below −250 mV and concrete resistivity ρ is above 4 kΩcm. The area around measuring points 3 to 9 from A to E is of type 2, which means that there is a uncertain probability of corrosion. In the measuring points, potential Ecorr is between −150 mV and −350 mV and concrete resistivity ρ is above 4 kΩcm. The area around measuring points 1 to 7 from A to I is of type 3, which means that there is an 10% probability of corrosion. In the measuring points, potential Ecorr is above −250 mV and concrete resistivity ρ is above 5 kΩcm.On the basis of Tables enerated  as it haA methodology for assessing the probability of corrosion in concrete slabs based on a combination of two nondestructive methods, that is, the half-cell potential method and the concrete resistivity method, was briefly described. Comparative tests were carried out using the two methods to determine the probability of corrosion in model test concrete slab specimens. The experimental results showed that the two nondestructive techniques can be used together in order to obtain maximum information about the probability of corrosion in a tested structure.This study was motivated by the engineer's need for a combination of the half-cell potential mapping technique and concrete resistivity measurements to more accurately assess the probability of corrosion. The combined techniques can be used in both the field and the laboratory environment. Moreover, they can be automated and integrated into monitoring systems for new or existing reinforced concrete structures. However, it is still recommended to perform additional tests for other rebar diameters, different aggregate grading, and a wider range of covers.


Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system. It is caused by the human immunodeficiency virus (HIV) which can be transmitted through direct contact of a mucous membrane or the bloodstream with a bodily fluid containing HIV.There was a significant difference between mean scores of knowledge and perceived susceptibility and educational field of participants (p < 0.001).The negative significant correlation between perceived severity with knowledge and perceived susceptibility indicates that the students who have not perceived susceptibility to and severity of a health problem like HIV/AIDS may ignore preventing behaviors. Moreover, the Health Belief Model can be used as a conceptual framework in interventional programs for HIV/AIDS.


Heroin dependence is a chronic relapsing brain disorder, characterized by the compulsion to seek and use heroin. Heroin itself has a strong potential to produce subjective experiences characterized by intense euphoria, relaxation and release from craving. The neurofunctional foundations of these perceived effects are not well known. In this study, we have used pharmacological magnetic resonance imaging (phMRI) in 15 heroin-dependent patients from a stable heroin-assisted treatment program to observe the steady state effects of heroin (60 min after administration). Patients were scanned in a cross-over and placebo controlled design. They received an injection of their regular dose of heroin or saline (placebo) before or after the scan. As phMRI method, we used a pulsed arterial spin labeling (ASL) sequence based on a flow-sensitive alternating inversion recovery (FAIR) spin labeling scheme combined with a single-shot 3D GRASE (gradient-spin echo) readout on a 3 Tesla scanner. Analysis was performed with Statistical Parametric Mapping (SPM 8), using a general linear model for whole brain comparison between the heroin and placebo conditions. We found that compared to placebo, heroin was associated with reduced perfusion in the left anterior cingulate cortex (ACC), the left medial prefrontal cortex (mPFC) and in the insula (both hemispheres). Analysis of extracted perfusion values indicate strong effect sizes and no gender related differences. Reduced perfusion in these brain areas may indicate self- and emotional regulation effects of heroin in maintenance treatment. In heroin-dependent patients, acute and chronic exposure to heroin is associated with impairments in a range of cognitive processes, including impulse control dysfunction However, the neurofunctional foundations of the effects mediated by heroin administration are not well understood. Pharmacological magnetic resonance imaging (phMRI) permits an in vivo examination of how psychotropic drugs affect neural network function in the brain http://clinicaltrials.gov; ID NCT01174927). Each patient was scanned twice, with a short interval between scans (mean 9 SD 3.8 days). On one day, the subjects received an injection of heroin or placebo  before the scan and on the other after the scan. Patients received their regular morning dose of diacetylmorphine, corresponding to half of their daily dose. The order of heroin and placebo administration was randomized and patients were blinded to what they received. A study nurse administered the substance intravenously 20 minutes before the scanning session started. The ASL perfusion data were acquired one hour after injection , corresponding to the euphoria phase during heroin condition.This study is part of a randomized, placebo-controlled clinical trial that has been registered  Fifteen  non-left-handed heroin-dependent patients (ICD-10 = F11.22) were included in the study. All subjects participated in a national program of standardized DAM (“heroin”)-assisted treatment . Participants were told to abstain from illicit drug use other than prescribed heroin for the duration of the study, from alcohol intake for 72 hours and from tobacco consumption for 2 hours before scanning. Illicit substances and medications were controlled by a urine test at each session. The exclusion criteria were a positive alcohol breathalyzer test, a history of significant medical problems or a major mental disorder (other than substance use disorders).http://www.ekbb.ch/]) approved the study. Patients were informed that they received their regular heroin dose  before or after the scan.All patients gave written informed consent and Basel Ethics Committee  of 2000 ms, inversion time (TI) of 1000 ms and echo time (TE) of 3.4 ms. For perfusion data, a pulsed ASL sequence 3 (interpolated to 2.3×2.3×4 mm3).Imaging was performed on a 3 Tesla MRI scanner  at Basel University Hospital. For high resolution anatomical data, a 3D T1-weighted scan (MPRAGE) was acquired with 1×1×1 mmhttp://med.inria.fr).Maps of quantified CBF (perfusion maps) were calculated from ASL raw data. Difference images of label and control images at different TI were derived and the time course was fitted to a model describing different stages of arterial blood passage, using in-house software, Further image processing and analyses were performed using Statistical Parametric Mapping . At the subject level, MPRAGE images were segmented to gray matter (GM) and intracranial tissue . Perfusion maps were reoriented to the standard direction. Both conditions were first realigned and then coregistered to segmented GM images, resulting in optimal MPRAGE coregistration. Then perfusion maps were masked with binarized ICT (binarization threshold: voxel intensity >0.1) to remove the extracerebral signal. The resulting perfusion maps were normalized to standard stereotactic MNI  space by applying the transformation parameters of normalized MPRAGE images. Finally normalized perfusion maps were smoothed using a 6 mm full-width-at half-maximum (FWHM) Gaussian kernel. All processed images were assessed with respect to quality and registration. See preprocessing steps in http://www.talairach.org/client.html).At the group level, a voxel-wise whole brain comparison between the heroin and placebo conditions was performed with a basic general linear model (GLM). A proportional scaling method in SPM8 was used to normalize each subject's perfusion maps. MNI coordinates of significant clusters were converted into Talairach space and labeled with the Talairach Client 2.4.3 (We performed a repeated measures (within-subject) analysis of variance (ANOVA) for whole brain analysis. Pre-processed heroin and placebo perfusion maps were used as input data. The following tests were applied: heroin < placebo (higher perfusion during heroin) and heroin > placebo (lower perfusion during heroin). Statistical significance was assessed at the cluster-forming threshold of p<0.01 (uncorrected). At the cluster level, only clusters with p<0.05 corrected for family-wise error (FWE) were considered significant The patients mean age was 41 years, they were heroin dependent for a mean of 21 years and had participated in the heroin-assisted treatment for a mean of 8 years. Mean daily heroin dose was 350 mg. Male and female patients didn't differ significantly in age (p = 0.10), duration of heroin dependence (p = 0.76), duration of heroin maintenance (p = 0.70) and daily dose of heroin (p = 0.44). Some patients also illicitly used other drugs, one third of patients had an additive substitution with a small dose of methadone. All participants were cigarette smokers. None of patients had abused alcohol. The patients' characteristics are described in In the heroin condition, patients had significantly lower heart rates and blood oxygen saturation, as shown in All patients correctly guessed the substance they had received before the scanning procedure. Perceived drug effects, feeling of intoxication and sedation, and relief from withdrawal were significantly higher during heroin condition than during the placebo condition (p<0.01). The desire to use heroin did not differ significantly between the two conditions. See the psychological effects of heroin in Compared to placebo, heroin administration was associated with relatively low perfusion in three main clusters (threshold: p<0.01). The first two clusters are within the area of the left and right insula . The third cluster is in the area of the medial frontal cortex, with peaks in the anterior cingulate cortex (ACC) and the medial frontal gyrus (mPFC) . No significant hyperperfusion (relative to placebo) was associated with heroin administration. Brain perfusion characteristics are shown in Extracted mean perfusion values of significant clusters are shown in To our knowledge, this is the first study to measure selective heroin effects during the euphoria phase with an advanced phMRI method. We found that heroin administration in heroin-dependent patients is associated with a significant reduction in perfusion in the insula of both hemispheres, the anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) with strong effect sizes. Whereas the insula and ACC play an essential role in emotional regulation and self-awareness A previous study examined the acute effects of heroin using functional neuroimaging Interestingly, previous studies with the short acting opioid remifentanyl, which is used in anesthesia, showed that its acute effects leads to regional hyperpferusion in the ACC The differences in perfusion, recognized by comparing the heroin and placebo conditions, may also be caused by hyperperfusion after placebo, which could be associated with withdrawal and craving. In general, placebo may induce craving and withdrawal symptoms in heroin-dependent patients The present heroin-associated modulation of perfusion in prefrontal and extended limbic regions may also be related to the abnormal cerebral volumes reported in heroin-dependent patients This reduced perfusion in these areas may underlay the feelings perceived by heroin users, such as relaxation and euphoria The moderate number of participants limits our findings. Moreover, our patients were recruited from a population, which mainly consisted of individuals with long-standing polysubstance use. Although this problem is virtually inevitable when chronic heroin-dependent individuals are examined, it may have biased the results. Another limitation is the lack of a healthy control group and the use of an inactive placebo that could lead to withdrawal symptoms.To conclude, our findings demonstrate that acute administration of heroin results in reduced brain activity within the left anterior cingulate cortex (ACC), the left medial prefrontal cortex (mPFC) and in the insula (both hemispheres). Reduced perfusion in these prefrontal and extended limbic areas may indicate self- and emotional regulation effects of heroin maintenance treatment.


The authors report a case of metastatic gastrointestinal adenocarcinoma to the cervical spine in a patient with acquired immunodeficiency syndrome (AIDS) being treated with antiretroviral therapy. The source of this tumor could not be identified despite a thorough evaluation. A 49-year-old male being treated for AIDS presents with worsening neck pain and left distal arm weakness. MRI demonstrated an erosive mass within the cervical four vertebral body extending through the pedicle on the left side. Patient underwent needle biopsy followed by combined anterior and posterior fusion procedures. Pathology demonstrated metastatic gastrointestinal adenocarcinoma without known primary origin. He is currently undergoing palliative radiotherapy. This is an unusual case of metastatic gastrointestinal adenocarcinoma to the cervical spine. This should be included on the differential diagnosis of spinal lesions in this patient population and may represent a unique tumor in patients with HIV/AIDS who are on immunosuppressive therapy. The authors report an unusual case of symptomatic metastatic gastrointestinal adenocarcinoma without known primary tumor to the cervical spine in a patient with AIDS on chronic antiretroviral therapy.We report the case of a 49-year-old homosexual male being treated for AIDS who presented with worsening neck pain and left distal arm and hand weakness. MRI demonstrated an erosive mass within the C4 vertebral body extending through the pedicle on the left side and causing severe spinal stenosis Figures  and 2. APatient underwent needle biopsy followed by anterior cervical corpectomy and fusion and finally posterior lateral mass instrumentation and fusion . PatholoThe patient was successfully treated for post-operative cerebrospinal fluid collection in the neck with a lumbar drain. His neurological examination returned to its baseline. His CD4 counts remained stable preoperatively and postoperatively. He is currently undergoing palliative radiotherapy with 37.5 Gy over 15 fractions to his cervical spine.AIDS-defining cancers, such as Kaposi's sarcoma, non-Hodgkin's lymphoma, and cervical cancer, are quite common in patients with end-stage AIDS –3. Over  Some authors have argued that there is an association between chronic AIDS and human immunodeficiency syndrome (HIV) infection and the occurrence of colonic malignancy . StudiesAbout 10% of all cancer patients develop metastases to the spine , 5. AmonRavalli et al. noted in their seminal report three patients with HIV in less than one year who developed gastrointestinal carcinoma and suggested an increased frequency in this population . GastroiThis case stimulates interest in a possible association between AIDS/HIV, long-term antiretroviral therapy, and metastatic gastrointestinal adenocarcinoma without a clear primary site. We wonder if this particular metastatic gastrointestinal tumor is a unique tumor of the gastrointestinal system that is associated with chronic HIV/AIDS or chronic immunotherapy. In conclusion, this pathology must be kept on the differential diagnosis list in this patient population and further cases must be documented to clearly confirm this association.


Many fundamental patterns of coinfection (multi-species infections) are undescribed, including the relative frequency of coinfection by various pathogens, differences between single-species infections and coinfection, and the burden of coinfection on human health. We aimed to address the paucity of general knowledge on coinfection by systematically collating and analysing data from recent publications to understand the types of coinfection and their effects.From an electronic search to find all publications from 2009 on coinfection and its synonyms in humans we recorded data on i) coinfecting pathogens and their effect on ii) host health and iii) intensity of infection.The most commonly reported coinfections differ from infections causing highest global mortality, with a notable lack of serious childhood infections in reported coinfections. We found that coinfection is generally reported to worsen human health (76% publications) and exacerbate infections (57% publications). Reported coinfections included all kinds of pathogens, but were most likely to contain bacteria.These results suggest differences between coinfected patients and those with single infections, with coinfection having serious health effects. There is a pressing need to quantify the tendency towards negative effects and to evaluate any sampling biases in the coverage of coinfection research. The many pathogens that infect humans  often co-occur within individuals.Improved understanding of coinfection prevalence is greatly needed,Reviews of coinfection have emphasised that coinfection requires further research, especially in humans,We searched the published literature for studies of coinfection (i.e. multi-species infections) in humans using the Advanced Search facility on the largest online citation database, Scopus (Elsevier Ltd.). Many disciplines study infectious diseases and various terms are used to describe coinfection. We therefore searched for coinfection, concomitant infection, multiple infection, concurrent infection, simultaneous infection, double infection, polymicrobial, polyparasitism, or multiple parasitism in the Title, Abstract, or Keywords of publications in the Life and Health Sciences before 2010. In June 2011 this search returned 12,963 results; an equivalent search on an alternative online citation database, Web of Science [Thomson Reuters], yielded similar trends in publications through time, but fewer results. Due to the large number of publications matching the search terms, we chose to focus on publications from 2009. Furthermore, publications concerning non-human hosts, non-infectious diseases or multiple genotypes of only one pathogen species were excluded.For each publication we collected data on the identity of coinfecting pathogens, journal, study type and maximum number of pathogen species found per person. Study types included experiments treating each infection, observational studies, and reviews/meta-analyses. Observational studies were either case notes on particular patients, studies of patient groups, or epidemiological surveys among human communities.Many publications reported the stated effect of one pathogen on the abundance of coinfecting pathogens  and/or host health . These effects of coinfection are relative to conditions observed under infections of single pathogen species. Where these effects were reported we recorded the pair of coinfecting pathogens involved, the quality of measurement  and other data (see below). Data from review-type publications, case notes and from publications not mentioning the effects of coinfection  were excluded to avoid double counting, undue influence of individual cases and the inclusion of irrelevant publications. Reported effects based on low quality evidence  were also omitted.P-values, hazards ratios, raw comparisons). Furthermore, many publications gave qualitative statements of effect direction. Among publications quantifying effect size, diverse measures were given across publications. We focused on the direction of reported effects  to maximise the data available. Reported directions of the effects on both pathogen abundance and host health for each pair of coinfecting pathogens was coded +1 for positive effect, 0 for neutral, −1 for negative effects, and NA if no information about effect direction was given. The resulting dataset includes some repeated measures because some publications reported multiple pairs of coinfecting pathogens and some coinfections were reported in multiple publications. We created two independent datasets containing the mean effect direction (i) per publication and (ii) per coinfection to eliminate these sources of pseudoreplication. A negative mean implied a predominance of negative effects; a positive mean implied a dominance of positive effects. A mean close to 0 could result from either many neutral effects (whereby a pathogen consistently had no discernible effect) and/or equal numbers of positive and negative effects . In either case, there is no clear indication of these pathogens having a consistent effect on each other , so we adopt the most conservative interpretation and assume there is no-effect. These means were converted into three categories: negative (−1 to −⅓), neutral (−1 to +⅓) and positive (+⅓ to +1). Chi-squared testsα = 0.05).There was considerable heterogeneity in the reporting of the effects of coinfection, both in terms of the response variable and in terms of the quantitative measure given  on the effects of coinfection in the analysis . These values represent reported coinfections where the effect on either pathogen abundance or host health was not reported, despite the possibility that these coinfecting pathogens did interact with each other and/or influence host health. We therefore assessed how potential interactions from these unreported effects may alter the overall patterns of coinfection effects. To determine their potential impact on the estimated overall effects, NAs were assigned one of three values at random . The mean effect was then calculated per publication or coinfection pair as before, and a grand mean taken across all publications or coinfection-pairs. The grand mean represents an estimate of overall effect of coinfection on either host health or pathogen abundance across either publications or coinfections, given a particular random assignment of −1, 0, +1 to NAs. Repeating this random assignment 1000 times produced a distribution of grand means.We examined whether recent coinfection research focuses on the pathogens causing the highest global mortality. We obtained global totals for the number of deaths  in 2009 under every category of infection collated by the World Health Organisation .Hundreds of publications on coinfection are published annually and have increased from 219 publications in the first year of search results to 1464 publications in 2009 . This inThe majority of relevant publications from 2009 were observational studies , of which 159 (67.9%) involved patient groups, 60 (25.6%) were case notes and 18 (7.7%) surveyed a population. Three observational studies (1.3%) analysed death records. Seventy publications (22.4%) were reviews or metaanalyses. Five publications (1.6%) were experimental, whereby treatment and controls were applied to both singly infected and coinfected groups. A majority of the relevant publications concerned coinfections by two pathogen species , but more pathogen species per individual were occasionally reported; the mean number of pathogens was 2.4 and a maximum of 13 pathogens was reported twice in a venous leg ulcerA total of 270 pathogen taxa were reported in coinfection publications from 2009, across 1265 reports of coinfections comprising 933 different pairs of coinfecting pathogen taxa. All pathogen types  were reported in coinfections; the most common pathogen group was bacteria . In termEffects of coinfection on pathogen abundance and host health were sampled across 173 suitable publications according to pathogen abundance and host health. These publications covered 827 coinfecting pairs of pathogens, involving 183 pathogen species. Among these coinfections, 203 (24.5%) measured the size or direction of effects on pathogen abundance and 191 (23.1%) measured the size or direction of effects on host health. The remainder of coinfections had no reports of the effects of coinfection in suitable publications.X2 = 15.6, d.f. = 2, P < 0.001] and by coinfection ) and from the no-effect null model .Overall, positive effects of coinfection on pathogen abundance were the most common reported across publications , Escherichia coli (4.43%), Pseudomonas aeruginosa (3.72%), Mycobacterium tuberculosis (5.9%), HPV (3.16%), unidentified Streptococcus spp. (3.00%), and unidentified Staphylococcus spp. (3.00%). Some of the most common reported coinfecting pathogens  contribute relatively little to global infection mortality. Perhaps surprisingly, four of the most important infectious causes of mortality  received very few or no reports of coinfection in 2009 publications.We found notable differences between the most commonly reported coinfecting pathogens and the infections causing the greatest global health burden . The larInterest in coinfection has increased in recent years, with publications on human coinfection involving hundreds of pathogen taxa across all major pathogen groups. Recent publications tend to show that negative effects of coinfection on human health are more frequent than no-effect or positive effects. However, the most commonly reported coinfecting pathogens differ from those infections causing highest global mortality. These results raise questions concerning the occurrence and study of coinfection in humans and their implications for effective infectious disease management.P < 0.001) from expectations of either no-effect or of random distributions, and by the robustness of these trends in the face of missing values and by diversity in the types of publications in which these coinfections were reported. Moreover the tendency for positive effects on pathogen abundance corroborates the negative effects on host health because larger infections are a mechanism by which disease can be exacerbated. The consistency of these detrimental coinfection effects across a wide range of pathogens suggests a general incidence of interactions between coinfections. The long-term effects among survivors of coinfections can be varied and in some cases severe, including blindness, chronic diarrhoea, chronic inflammation, carcinoma, immunosuppression, liver fibrosis, meningitis, renal failure, rheumatic fever, etc.The overall consequence of reported coinfections was poorer host health and enhanced pathogen abundance, compared with single infections. This is strongly supported by significant statistical differences in the reported direction of effects (The direction of reported coinfection effects could have at least two explanations. The first is that coinfection may be more likely in individuals of poor health, which in turn leads to poorer prognosis among coinfected cases. The relative paucity of experimental studies of coinfection in humans means sampling biases towards people of poorer health is possible, but impossible to account for in our analyses. The second explanation is that coinfecting pathogens interact synergistically with each other, for example via the host’s immune system, so that the presence of one enhances the abundance and/or virulence of the other. A clear example of this is HIV, which causes immunosuppression, increasing the likelihood of additional infections and occurred in two fifths of reported coinfections .P. aeruginosa exoproduct limiting S. aureus colony formation.Differences between reported coinfections and global mortality figures may also suggest important interactions between coinfecting pathogens. Coinfections that were more commonly reported than their relative contribution to global mortality may involve particular synergistic pathogen–pathogen interactions, such as among herpes viruses like CMV or HSV infection enhancing the risk of HPV coinfection.The disparity between infections that feature highly in global mortality statistics and those receiving most attention in published coinfection studies poses a challenge to infectious disease research. A general understanding of the effects of coinfection is important for appropriate control of infectious diseases.Overall recently published reports of coinfection in humans show coinfection to be detrimental to human health. Understanding the nature and consequences of coinfection is vital for accurate estimates of infectious disease burden. In particular, more holistic data on infectious diseases would help to quantify the size of the effects on coinfection on human health. Improved knowledge of the factors controlling an individual’s risk of coinfection, circumstances when coinfecting pathogens interact, and the mechanisms behind these pathogen–pathogen interactions, especially from experimental studies, will also aid the design and evaluation of infectious disease management programmes. To date, most disease control programs typically adopt a vertical approach to intervention, dealing with each pathogen infection in isolation. If coinfecting pathogens generally interact to worsen human health, as suggested here, control measures may need to be more integrated and specialist treatments developed for clinical cases of coinfection. Further research is needed to identify the role of predisposed risks to coinfection.