The F-box protein gene exo-1 is a target for reverse engineering enzyme hypersecretion in filamentous fungi.

Carbohydrate active enzymes (CAZymes) are vital for the lignocellulose-based biorefinery. The development of hypersecreting fungal protein production hosts is therefore a major aim for both academia and industry. However, despite advances in our understanding of their regulation, the number of promising candidate genes for targeted strain engineering remains limited. Here, we resequenced the genome of the classical hypersecreting Neurospora crassa mutant exo-1 and identified the causative point of mutation to reside in the F-box protein-encoding gene, NCU09899. The corresponding deletion strain displayed amylase and invertase activities exceeding those of the carbon catabolite derepressed strain Δcre-1, while glucose repression was still mostly functional in Δexo-1 Surprisingly, RNA sequencing revealed that while plant cell wall degradation genes are broadly misexpressed in Δexo-1, only a small fraction of CAZyme genes and sugar transporters are up-regulated, indicating that EXO-1 affects specific regulatory factors. Aiming to elucidate the underlying mechanism of enzyme hypersecretion, we found the high secretion of amylases and invertase in Δexo-1 to be completely dependent on the transcriptional regulator COL-26. Furthermore, misregulation of COL-26, CRE-1, and cellular carbon and nitrogen metabolism was confirmed by proteomics. Finally, we successfully transferred the hypersecretion trait of the exo-1 disruption by reverse engineering into the industrially deployed fungus Myceliophthora thermophila using CRISPR-Cas9. Our identification of an important F-box protein demonstrates the strength of classical mutants combined with next-generation sequencing to uncover unanticipated candidates for engineering. These data contribute to a more complete understanding of CAZyme regulation and will facilitate targeted engineering of hypersecretion in further organisms of interest.

Purification and characterization of a native lytic polysaccharide monooxygenase from Thermoascus aurantiacus.

Lytic polysaccharide monooxygenases (LPMOs) have emerged as key proteins for depolymerization of cellulose. These copper-containing enzymes oxidize C-1 and/or C-4 bonds in cellulose, promoting increased hydrolysis of the oxidized cellulose chains. The LPMO from Thermoascus aurantiacus, a thermophilic ascomycete fungus, has been extensively studied and has served as a model LPMO. A method was developed to purify the LPMO from culture filtrates of T. aurantiacus along with its native cellobiohydrolase and endoglucanase. The activity of the purified LPMO was measured with a colorimetric assay that established the Topt of the native LPMO at 60 °C. Purification of the components of the T. aurantiacus cellulase mixture also enabled quantification of the amounts of cellobiohydrolase, endoglucanase and LPMO present in the T. aurantiacus culture filtrate, establishing that the LPMO was the most abundant protein in the culture supernatants. The importance of the LPMO to activity of the mixture was demonstrated by saccharifications with Avicel and acid-pretreated corn stover.

Orotracheal intubation in infants performed with a stylet versus without a stylet.

BACKGROUND: Neonatal endotracheal intubation is a common and potentially life-saving intervention. It is a mandatory skill for neonatal trainees, but one that is difficult to master and maintain. Intubation opportunities for trainees are decreasing and success rates are subsequently falling. Use of a stylet may aid intubation and improve success. However, the potential for associated harm must be considered. OBJECTIVES: To compare the benefits and harms of neonatal orotracheal intubation with a stylet versus neonatal orotracheal intubation without a stylet. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE; Embase; the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and previous reviews. We also searched cross-references, contacted expert informants, handsearched journals, and looked at conference proceedings. We searched clinical trials registries for current and recently completed trials. We conducted our most recent search in April 2017. SELECTION CRITERIA: All randomised, quasi-randomised, and cluster-randomised controlled trials comparing use versus non-use of a stylet in neonatal orotracheal intubation. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed results of searches against predetermined criteria for inclusion, assessed risk of bias, and extracted data. We used the standard methods of the Cochrane Collaboration, as documented in the Cochrane Handbook for Systemic Reviews of Interventions, and of the Cochrane Neonatal Review Group. MAIN RESULTS: We included a single-centre non-blinded randomised controlled trial that reported a total of 302 intubation attempts in 232 infants. The median gestational age of enrolled infants was 29 weeks. Paediatric residents and fellows performed the intubations. We judged the study to be at low risk of bias overall. Investigators compared success rates of first-attempt intubation with and without use of a stylet and reported success rates as similar between stylet and no-stylet groups (57% and 53%) (P = 0.47). Success rates did not differ between groups in subgroup analyses by provider level of training and infant weight. Results showed no differences in secondary review outcomes, including duration of intubation, number of attempts, participant instability during the procedure, and local airway trauma. Only 25% of all intubations took less than 30 seconds to perform. Study authors did not report neonatal morbidity nor mortality. We considered the quality of evidence as low on GRADE analysis, given that we identified only one unblinded study. AUTHORS' CONCLUSIONS: Current available evidence suggests that use of a stylet during neonatal orotracheal intubation does not significantly improve the success rate among paediatric trainees. However, only one brand of stylet and one brand of endotracheal tube have been tested, and researchers performed all intubations on infants in a hospital setting. Therefore, our results cannot be generalised beyond these limitations.

The meaning of menarche: A cross-cultural semantic network analysis.

The psychological meaning of menarche was explored in 102 college students from Mexico and the United States. The Natural Semantic Networks Technique was used and participants were asked to respond to the prompt "My first period was …" The strongest components of the Mexican women's semantic network were scary, confusing, and unexpected; the strongest components of the American women's semantic network were unexpected, annoying, and painful. Only the Americans listed positive words (i.e., nice). The Mexicans' network contained the most negative words (i.e., dirty). The results suggest a need for better education and greater social support, especially in Mexico.

Queer periods: attitudes toward and experiences with menstruation in the masculine of centre and transgender community.

Menstruation has long been viewed as an important aspect of women's health. However, scholars and healthcare providers have only recently begun to recognise that transgender men and people with masculine gender identities also menstruate, thus little is known about their attitudes toward and experiences with menstruation. A sample of masculine of centre and transgender individuals with a mean age of 30 years was recruited online to complete measures of attitudes toward menstruation and menstrual suppression and to answer exploratory questions about their experiences managing menstruation. Participants reported mixed attitudes toward menstruation, but generally positive attitudes toward menstrual suppression. Many participants said that they try to avoid public restrooms during menstruation because of practical and psychological concerns. Implications of our findings for the transgender health are discussed.

Carotenoid production and gene expression in an astaxanthin-overproducing Xanthophyllomyces dendrorhous mutant strain.

The primary carotenoid synthesized by Xanthophyllomyces dendrorhous is astaxanthin, which is used as a feed additive in aquaculture. Cell growth kinetics and carotenoid production were correlated with the mRNA levels of the idi, crtE, crtYB, crtI, crtS and crtR genes, and the changes in gene sequence between the wild-type and a carotenoid overproducer XR4 mutant strain were identified. At the late stationary phase, the total carotenoid content in XR4 was fivefold higher than that of the wild-type strain. Additionally, the mRNA levels of crtE and crtS increased during the XR4 growth and were three times higher than the wild-type strain in the late stationary phase. Moreover, the nucleotide sequences of crtYB, crtI and crtR exhibited differences between the strains. Both the higher crtE and crtS transcript levels and the crtYB, crtI and crtR mutations can, at least in part, act to up-regulate the carotenoid biosynthesis pathway in the XR4 strain.

Burden of migraine related to menses: results from the AMPP study.

BACKGROUND: Studies of the difference between menstrually associated and non-menstrually associated migraine are somewhat controversial. The majority of studies have focused on comparing menstrual to non-menstrual attacks rather than comparing study groups with different migraine diagnoses with respect to menstruation. As there is limited knowledge available on the overall impact and burden of migraine among groups of women with and without menstrually associated migraine our goal was to examine differences between these groups. We hypothesized that there would be greater burden of migraine related to menstruation and headache frequency in a population study across groups of women. METHODS: We analyzed data from the American Migraine Prevalence and Prevention (AMPP) Study, a longitudinal, US, population-based study. We included female respondents to the 2009 survey, aged 18 to 60, who met modified ICHD-2 criteria for migraine, were actively menstruating and fit one of three definitions based on the self-reported association of menses and migraine attacks: self-reported predominantly menstrual migraine (MM, attacks that only or predominantly occur at the time of menses), self-reported menstrually-associated migraine (MAM, attacks commonly associated with menses, but that also occur at other times of the month), and self-reported menstrually-unrelated migraine (MUM). These three groups were compared on characteristics and measures of headache impact and burden (Headache Impact Test- 6 item (HIT-6) and Migraine Disability Assessment Scale (MIDAS). RESULTS: There were 1,697 eligible subjects for this study in the following categories: MM (5.5%), MAM (53.8%), or MUM (40.7%). Women with MM had an older age of migraine onset. Those with predominantly menstrually-related attacks (MM) had fewer headache-days but appeared to be more impaired by attacks. HIT-6 and MIDAS scores were significantly higher for both the MM and MAM groups compared with the MUM groups; however, effects were more robust for MM than MAM. CONCLUSIONS: Nearly 60% of women with migraine reported an association between migraine and menses. These women reported greater headache impact and migraine-related burden on functioning than those in whom migraines were not related to menstruation. Women with MM were more impaired by attacks while women with MAM had overall highest burden, likely due to experiencing migraines on additional days.

Randomized controlled trial comparing two procedures for anterior vaginal wall prolapse.

OBJECTIVE: To compare success rates between anterior colporrhaphy and abdominal paravaginal defect repair for treatment of anterior vaginal wall prolapse. METHODS: This was a prospective randomized controlled trial comparing anterior colporrhaphy plus polyglactin 910 mesh (vaginal) to paravaginal defect repair (abdominal) in women with symptomatic anterior vaginal wall prolapse. Pelvic organ prolapse quantification staging (POP-Q), pelvic floor distress inventory, pelvic floor impact questionnaire, and pelvic organ prolapse/urinary incontinence sexual questionnaires were administered pre and post-operatively. Women were followed up to 2 years. The primary outcome was anterior POP-Q stage, with failure defined as ≥stage II. RESULTS: We enrolled 70 patients, 35 in each group. Demographic and most peri-operative characteristics were similar between the groups. Mean anterior vaginal wall prolapse repair time (39 min) was shorter for vaginal versus abdominal repair (60 min; P < 0.001), with more concurrent hysterectomies in the vaginal (71%) versus abdominal group (42%), P = 0.01. At 2 years, objective failure rates for the vaginal and abdominal groups were 32% and 40%, respectively, P = 0.56. Subjective failure rates were lower and similar for both groups. Patient satisfaction rates were 88% for the vaginal and 73% for the abdominal group, P = 0.11. Quality of life questionnaires showed significant improvement from baseline but no difference between the groups (P = 0.12). CONCLUSIONS: At 2 years follow-up, anterior colporrhaphy with polyglactin 910 mesh and abdominal paravaginal defect repair have similar success rates, with most objective failures being asymptomatic.

Ambivalent sexism and attitudes toward women in different stages of reproductive life: a semantic, cross-cultural approach.

College students in southeastern Mexico (n = 185) and the northeastern United States (n = 96) utilized a semantic differential scale to rate subtypes of women: a menstruating woman, a menopausal woman, a pregnant woman, a premenstrual woman, a woman with a hysterectomy, a teenage girl, a woman in love, and a woman with a young baby. Americans reported significantly more negative attitudes than Mexicans did toward a menstruating woman, a premenstrual woman, a teenage girl, and a pregnant woman. Participants chose more positive words to describe a teenage girl, a woman in love, a pregnant woman, and a woman with a young baby, which is suggestive of a pronatal bias. Participants also completed the Ambivalent Sexism Inventory (ASI). Men scored significantly higher than women on hostile sexism. Mexicans scored significantly higher than Americans on both hostile and benevolent sexism. Sexism scores are related to attitudes toward premenstrual, menstruating, and menopausal women; women with a hysterectomy; and women with a young baby.

Prevalence, characteristics and clinical impact of work-related musculoskeletal pain in echocardiography.

BACKGROUND: Work-related musculoskeletal pain (WRMSP) is increasingly recognised in cardiac ultrasound practice. WRMSP can impact workforce health, productivity and sustainability. We sought to investigate the prevalence, characteristics and clinical impact of WRMSP. METHODS: Prospective electronic survey of 157 echocardiographers in 10 institutions. Data acquired on demographics, experience, working environment/pattern, WRMSP location, severity and pattern, the impact on professional, personal life and career. RESULTS: 129/157 (82%) echocardiographers completed the survey, of whom 109 (85%) reported WRMSP and 55 (43%) reported work taking longer due to WRMSP. 40/129 (31%) required time off work. 78/109 (60%) reported sleep disturbance with 26/78 (33%) of moderate or severe severity. 56/129 (45%) required medical evaluation of their WRMSP and 25/129 (19%) received a formal diagnosis of musculoskeletal injury. Those with 11+ years of experience were significantly more likely to receive a formal diagnosis of WRMSP (p = 0.002) and require medication (p = 0.006) compared to those with 10 years or less experience. CONCLUSION: WRMSP is very common amongst echocardiographers, with a fifth having a related musculoskeletal injury. WRMSP has considerable on impact on personal, social and work-related activities. Strategies to reduce the burden of WRMSP are urgently required to ensure sustainability of the workforce and patient access to imaging.

Sex differences in the prevalence, symptoms, and associated features of migraine, probable migraine and other severe headache: results of the American Migraine Prevalence and Prevention (AMPP) Study.

BACKGROUND: The strikingly higher prevalence of migraine in females compared with males is one of the hallmarks of migraine. A large global body of evidence exists on the sex differences in the prevalence of migraine with female to male ratios ranging from 2:1 to 3:1 and peaking in midlife. Some data are available on sex differences in associated symptoms, headache-related disability and impairment, and healthcare resource utilization in migraine. Few data are available on corresponding sex differences in probable migraine (PM) and other severe headache (ie, nonmigraine-spectrum severe headache). Gaining a clear understanding of sex differences in a range of severe headache disorders may help differentiate the range of headache types. Herein, we compare sexes on prevalence and a range of clinical variables for migraine, PM, and other severe headache in a large sample from the US population. METHODS: This study analyzed data from the 2004 American Migraine Prevalence and Prevention Study. Total and demographic-stratified sex-specific, prevalence estimates of headache subtypes (migraine, PM, and other severe headache) are reported. Log-binomial models are used to calculate sex-specific adjusted prevalence ratios and 95% confidence intervals for each across demographic strata. A smoothed sex prevalence ratio (female to male) figure is presented for migraine and PM. RESULTS: One hundred sixty-two thousand seven hundred fifty-six individuals aged 12 and older responded to the 2004 American Migraine Prevalence and Prevention Study survey (64.9% response rate). Twenty-eight thousand two hundred sixty-one (17.4%) reported "severe headache" in the preceding year (23.5% of females and 10.6% of males), 11.8% met International Classification of Headache Disorders-2 criteria for migraine (17.3% of females and 5.7% of males), 4.6% met criteria for PM (5.3% of females and 3.9% of males), and 1.0% were categorized with other severe headache (0.9% of females and 1.0% of males). Sex differences were observed in the prevalence of migraine and PM, but not for other severe headache. Adjusted female to male prevalence ratios ranged from 1.48 to 3.25 across the lifetime for migraine and from 1.22 to 1.53 for PM. Sex differences were also observed in associated symptomology, aura, headache-related disability, healthcare resource utilization, and diagnosis for migraine and PM. Despite higher rates of migraine diagnosis by a healthcare professional, females with migraine were less likely than males to be using preventive pharmacologic treatment for headache. CONCLUSIONS: In this large, US population sample, both migraine and PM were more common among females, but a sex difference was not observed in the prevalence of other severe headache. The sex difference in migraine and PM held true across age and for most other sociodemographic variables with the exception of race for PM. Females with migraine and PM had higher rates of most migraine symptoms, aura, greater associated impairment, and higher healthcare resource utilization than males. Corresponding sex differences were not observed among individuals with other severe headache on the majority of these comparisons. Results suggest that PM is part of the migraine spectrum whereas other severe headache types are not. Results also substantiate existing literature on sex differences in primary headaches and extend results to additional headache types and related factors.

Single allele loss-of-function mutations select and sculpt conditional cooperative networks in breast cancer.

The most common events in breast cancer (BC) involve chromosome arm losses and gains. Here we describe identification of 1089 gene-centric common insertion sites (gCIS) from transposon-based screens in 8 mouse models of BC. Some gCIS are driver-specific, others driver non-specific, and still others associated with tumor histology. Processes affected by driver-specific and histology-specific mutations include well-known cancer pathways. Driver non-specific gCIS target the Mediator complex, Ca++ signaling, Cyclin D turnover, RNA-metabolism among other processes. Most gCIS show single allele disruption and many map to genomic regions showing high-frequency hemizygous loss in human BC. Two gCIS, Nf1 and Trps1, show synthetic haploinsufficient tumor suppressor activity. Many gCIS act on the same pathway responsible for tumor initiation, thereby selecting and sculpting just enough and just right signaling. These data highlight ~1000 genes with predicted conditional haploinsufficient tumor suppressor function and the potential to promote chromosome arm loss in BC.

Pilot immunization of mice infected with an equine strain of Corynebacterium pseudotuberculosis.

This pilot study evaluated protection of an equine autogenous bacterin-toxoid vaccine against Corynebacterium pseudotuberculosis infection. Twenty-four BALB/c mice were inoculated with two doses of bacterin-toxoid vaccine or two injections of a placebo. Clinical, microbiologic, and pathologic outcomes were assessed after intradermal infection with one of two equine-origin C. pseudotuberculosis strains. Mice receiving bacterin-toxoid from fast-growing C. pseudotuberculosis showed significant protection from challenge infection, as evidenced by a higher survival rate, fewer gross and histopathologic lesions, and lower bacterial levels on culture. Successful protection via a vaccine against equine internal abscesses might provide supplementary management options against an important, potentially fatal disease.

Development of genetic tools for the thermophilic filamentous fungus Thermoascus aurantiacus.

BACKGROUND: Fungal enzymes are vital for industrial biotechnology, including the conversion of plant biomass to biofuels and bio-based chemicals. In recent years, there is increasing interest in using enzymes from thermophilic fungi, which often have higher reaction rates and thermal tolerance compared to currently used fungal enzymes. The thermophilic filamentous fungus Thermoascus aurantiacus produces large amounts of highly thermostable plant cell wall-degrading enzymes. However, no genetic tools have yet been developed for this fungus, which prevents strain engineering efforts. The goal of this study was to develop strain engineering tools such as a transformation system, a CRISPR/Cas9 gene editing system and a sexual crossing protocol to improve the enzyme production. RESULTS: Here, we report Agrobacterium tumefaciens-mediated transformation (ATMT) of T. aurantiacus using the hph marker gene, conferring resistance to hygromycin B. The newly developed transformation protocol was optimized and used to integrate an expression cassette of the transcriptional xylanase regulator xlnR, which led to up to 500% increased xylanase activity. Furthermore, a CRISPR/Cas9 gene editing system was established in this fungus, and two different gRNAs were tested to delete the pyrG orthologue with 10% and 35% deletion efficiency, respectively. Lastly, a sexual crossing protocol was established using a hygromycin B- and a 5-fluoroorotic acid-resistant parent strain. Crossing and isolation of progeny on selective media were completed in a week. CONCLUSION: The genetic tools developed for T. aurantiacus can now be used individually or in combination to further improve thermostable enzyme production by this fungus.

Treatment of ankylosing spondylitis by inhibition of tumor necrosis factor alpha.

BACKGROUND: There are few effective treatments for ankylosing spondylitis, which causes substantial morbidity. Because of the central role of tumor necrosis factor alpha in the spondyloarthritides, we performed a randomized, double-blind, placebo-controlled trial of etanercept, a recombinant human tumor necrosis factor receptor (p75):Fc fusion protein, in patients with ankylosing spondylitis. METHODS: Forty patients with active, inflammatory ankylosing spondylitis were randomly assigned to receive twice-weekly subcutaneous injections of etanercept (25 mg) or placebo for four months. The primary end point was a composite of improvements in measures of morning stiffness, spinal pain, functioning, the patient's global assessment of disease activity, and joint swelling. Patients were allowed to continue taking nonsteroidal antiinflammatory drugs, oral corticosteriods (< or =10 mg per day), and disease-modifying antirheumatic drugs at stable doses during the trial. RESULTS: Treatment with etanercept resulted in significant and sustained improvement. At four months, 80 percent of the patients in the etanercept group had a treatment response, as compared with 30 percent of those in the placebo group (P=0.004). Improvements over base-line values for various measures of disease activity, including morning stiffness, spinal pain, functioning, quality of life, enthesitis, chest expansion, erythrocyte sedimentation rate, and C-reactive protein, were significantly greater in the etanercept group. Longitudinal analysis showed that the treatment response was rapid and did not diminish over time. Etanercept was well tolerated, with no significant differences in rates of adverse events between the two groups. CONCLUSIONS: Treatment with etanercept for four months resulted in rapid, significant, and sustained improvement in patients with ankylosing spondylitis.

Body appreciation and attitudes toward menstruation.

Menstruation is an important function of the female body, yet it has rarely been included in research on body image. As women's attitudes toward menstruation are so often negative, this study was designed to examine whether women with positive body image would have more positive attitudes toward menstruation. Seventy-two American women, ages 18-45 years, were recruited online to complete the Body Appreciation Scale (Avalos et al., 2005) and the Beliefs about and Attitudes toward Menstruation Scale (Marván et al., 2006) and to answer some questions about their interest in menstrual suppression. Linear regressions showed that higher scores on body appreciation predicted more positive attitudes toward and beliefs about menstruation, but were not related to interest in menstrual suppression. Our findings may be useful in designing interventions to increase women's comfort with their bodies and bodily functions.

Reactions of Psychiatric Patients to Telepsychiatry.

Telepsychiatry could offer a viable medical service to remote or isolated social communities if it does not generate adverse reactions such as delusional ideation, particularly in patients in settlements without adequate exposure to mainstream culture and internet. We examined subjective reactions to telepsychiatry of randomly selected 84 psychiatric patients from remote locations in Ontario, Canada. They rated the quality of their teleconferencing sessions via 10 item questionnaire and were asked about advantages and disadvantages of telepsychiatry. The majority of patients indicated that they were able to communicate as if physically present (92.9%) and were comfortable with telepsychiatric service (95.2%). They found the sessions as beneficial as direct meetings with their psychiatrist (84.5%) and would use this service again (98.8%). There were no instances of telepsychiatry being associated with adverse reactions in patients from remote communities with inadequate exposure to modern mainstream culture and internet.

Knowledge of carbohydrate counting and insulin dose calculations among hospital staff in a regional general paediatrics unit.

The aim of this study was to assess the carbohydrate and insulin knowledge of the staff at Children's Ark at the University Hospital, Limerick. Carbohydrate counting and insulin dose calculations based on carbohydrates and blood sugars are integral to intensive insulin management of type 1 diabetes mellitus (T1DM). The PedCarbQuiz, a validated questionnaire, was modified, and applied to the staff on our general paediatrics ward. 48/70 eligible staff responded (rate 68 %). Overall knowledge was good: 75.5 % was the average score for correctly identifying foods containing carbohydrate. However, poor scores were obtained for calculating multiple items and meal values (average score 29 %), and exact values of insulin required (average score 38 %). These results highlight the need for re-education among staff on a general paediatrics ward, to empower ward staff to contribute effectively to the education and management of patients with T1DM.

The shared epitope and severity of rheumatoid arthritis.

After two decades of research involving thousands of RA patients, it is still not possible to precisely define the relation of HLA-DRB1 SE alleles to RA severity. Improvements in our understanding require more careful consideration of several factors such as ethnicity, gender, and the specific SE allele and genotype inherited. Large studies of heterogeneous groups of patients are required and indicate the need for collaborative efforts among researchers. In the interim, meta-analysis of the existing literature may provide some insight, because it allows utilization of the tremendous amount of research already completed. A preliminary meta-analysis highlighted the significant heterogeneity among the existing literature, and a more ambitious meta-analysis that uses individual patient-level data is currently ongoing. Profound implications exist for determination of the precise relationship between the SE and RA severity. This information could be valuable in identifying patients at greater risk of severe complications or as a stratification variable for clinical trials. Moreover, patients genetically predisposed to severe disease may benefit from early initiation of more aggressive therapy. Ultimately, clarification of the role of the SE may be valuable for the development of specific therapies directed toward DRB1 and related targets.

Systematic reviews and meta-analyses: an illustrated, step-by-step guide.

Systematic reviews and meta-analyses synthesize data from existing primary research, and well-conducted reviews offer clinicians a practical solution to the problem of staying current in their fields of interest. A whole generation of secondary journals, pre-appraised evidence libraries and periodically updated electronic texts are now available to clinicians. However, not all systematic reviews are of high quality, and it is important to be able to critically assess their validity and applicability. This article is an illustrated guide for conducting systematic reviews. A clear understanding of the process will provide clinicians with the tools to judiciously appraise reviews and interpret them. We hope that it will enable clinicians to conduct systematic reviews, generate high-quality evidence, and contribute to the evidence-based medicine movement.