Advances in our understanding of the pathogenesis of hemolytic uremic syndromes.

Hemolytic uremic syndrome (HUS) is major global health care issue as it is the leading cause of acute kidney injury in children. It is a triad of acute kidney injury, microangiopathic hemolytic anemia, and thrombocytopenia. In recent years, major advances in our understanding of complement-driven inherited rare forms of HUS have been achieved. However, in children 90% of cases of HUS are associated with a Shiga toxin-producing enteric pathogen. The precise pathological mechanisms in this setting are yet to be elucidated. The purpose of this review is to discuss advances in our understanding of the pathophysiology underlying HUS and identify the key questions yet to be answered by the scientific community.

Constraints on tree seedling establishment after fires: passing the germination bottlenecks.

Persistence and colonization by tree species in an environment following a fire depends on the effects on seed germination and seedling development. We used seeds of Kielmeyera coriacea and Qualea parviflora as a model to test the effects of high temperatures on germination and initial development of tree seedlings. We exposed the seeds to heat flow (70, 100, 130, 150 or 170 °C) for 2 or 5 min and compared the germination with that of unheated seeds (control). Seedlings were then harvested after 3, 7 or 15 days to evaluate aerial and root mass, root:shoot ratio, presence of cotyledon opening, true leaves, and secondary roots. We found no effect on germination for seeds exposed to temperatures ≥150 °C. However, germination was significantly reduced for seeds exposed to 100 °C for both 2 and 5 min. The mass of 15-day-old K. coriacea seedlings was smaller when seeds were heated at 70 °C for 5 min or at temperatures higher or equal to 100 °C. Qualea parviflora seedlings did not show any difference in mass, but there were marginal differences in the presence of roots and the opening of cotyledons. Kielmeyera coriacea seedlings allocated biomass faster than Q. parviflora. High temperatures affect both quantity and quality of germinable seeds, as well as biomass allocation during initial seedling development. These factors may explain the decrease in seedlings observed after fire, suggesting a bottleneck effect that influences population dynamics and species persistence in systems with frequent fires.

Testing a Prostate Cancer Educational Intervention in High-Burden Neighborhoods.

To better capitalize on our enhanced understanding of prostate cancer (PCa) risk factors, it is important to better understand how knowledge and attitudes contribute to ethnic disparities in PCa outcomes. The goal of this study was to test the impact of a targeted PCa educational intervention vs. a healthy lifestyle educational control intervention on levels of knowledge, concern, and intention to screen for PCa.We recruited 239 men from neighborhoods with the highest PCa burden in Philadelphia. We assigned 118 men from two of the neighborhoods to the control group 121 men from 2 other neighborhoods to the intervention group. Repeated outcome assessment measures were obtained by administering the survey at baseline, post-session, 1 month post-session, and 4 months post-session.We conducted descriptive statistics to characterize the study sample and linear mixed effect regression models to analyze the intervention's effect on the outcomes. At baseline, we observed no differences in the outcomes between the PCa-targeted intervention and healthy lifestyle control groups.We found that knowledge of PCa and intention to screen increased significantly over time for both the control and intervention groups (p ≤ 0.01 at the 4-month follow-up). In contrast, change in the level of PCa concern was only significant for the intervention group immediately post-session and at 1-month follow-up (p = 0.04 and p = 0.01, respectively).This study showed that gathering at-risk men for discussions about PCa or other health concerns may increase their PCa knowledge and intention to talk to a doctor about PCa screening.

The dynamics of human cytomegalovirus replication in vivo.

Cytomegalovirus (CMV) is generally described as a slowly replicating virus. During studies of immunocompromised patients, we observed rapid changes in the quantity of CMV DNA present in serial blood samples by quantitative-competitive polymerase chain reaction commensurate with a doubling time of <2 d. To further investigate the dynamics of replication in vivo, patients in three distinct situations were studied in detail: (a) those receiving intravenous ganciclovir; (b) those in whom ganciclovir-resistant strains appeared during long-term therapy; and (c) those in whom ganciclovir-resistant strains disappeared with alternative drug therapy. In all cases, it was possible to provide accurate estimates of the doubling time of CMV and its half-life of disappearance after antiviral chemotherapy. The results from all three approaches demonstrated that the doubling time/half-life of CMV in blood is approximately 1 d when frequent samples are collected. These results show that CMV DNA replication in vivo is a highly dynamic process. We conclude that the reputation of CMV as a slowly replicating virus based on the time taken to produce cytopathic effects in vitro is unwarranted. These findings have implications for the potency, dose, and duration of antiviral chemotherapy needed for the effective treatment of this important human pathogen.

A review of the clinical and legal issues surrounding refusal of treatment following overdose.

This article reviews the clinical and legal issues involved in dealing with patients who refuse medical treatment following an overdose. We first describe a real case that has been made anonymous, before discussing a general approach to management. We then review the relevant legislation, including the Mental Capacity Act (2005), the Mental Health Act (1983) and legal issues surrounding the treatment of young people. We discuss how this legislation may be applied in practice and then conclude with the outcome of the case, sources of further information and some key learning points.

Measurement properties of tools used to assess suicidality in autistic and general population adults: A systematic review.

Adults diagnosed with autism are at significantly increased risk of suicidal thoughts, suicidal behaviours and dying by suicide. However, it is unclear whether any validated tools are currently available to effectively assess suicidality in autistic adults in research and clinical practice. This is crucial for understanding and preventing premature death by suicide in this vulnerable group. This two stage systematic review therefore aimed to identify tools used to assess suicidality in autistic and general population adults, evaluate these tools for their appropriateness and measurement properties, and make recommendations for appropriate selection of suicidality assessment tools in research and clinical practice. Three databases were searched (PsycInfo, Medline and Web of Knowledge). Four frequently used suicidality assessment tools were identified, and subsequently rated for quality of the evidence in support of their measurement properties using the COSMIN checklist. Despite studies having explored suicidality in autistic adults, none had utilised a validated tool. Overall, there was lack of evidence in support of suicidality risk assessments successfully predicting future suicide attempts. We recommend adaptations to current suicidality assessment tools and priorities for future research, in order to better conceptualise suicidality and its measurement in autism.

Measurement properties of tools used to assess depression in adults with and without autism spectrum conditions: A systematic review.

Depression is the most commonly experienced mental health condition in adults with autism spectrum conditions (ASC). However, it is unclear what tools are currently being used to assess depression in ASC, or whether tools need to be adapted for this group. This systematic review therefore aimed to identify tools used to assess depression in adults with and without ASC, and then evaluate these tools for their appropriateness and measurement properties. Medline, PsychINFO and Web of Knowledge were searched for studies of depression in: (a) adults with ASC, without co-morbid intellectual disability; and (b) adults from the general population without co-morbid conditions. Articles examining the measurement properties of these tools were then searched for using a methodological filter in PubMed, and the quality of the evidence was evaluated using the COSMIN checklist. Twelve articles were identified which utilized three tools to assess depression in adults with ASC, but only one article which assessed the measurement properties of one of these tools was identified and thus evaluated. Sixty-four articles were identified which utilized five tools to assess depression in general population adults, and fourteen articles had assessed the measurement properties of these tools. Overall, two tools were found to be robust in their measurement properties in the general population-the Beck Depression Inventory (BDI-II), and the patient health questionnaire (PHQ-9). Crucially only one study was identified from the COSMIN search, which showed weak evidence in support of the measurement properties of the BDI-II in an ASC sample. Implications for effective measurement of depression in ASC are discussed. Autism Res 2018, 11: 738-754. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc. LAY SUMMARY: Depression is the most common mental health problem experienced by adults with autism. However, the current study found very limited evidence regarding how useful tools developed for the general population are for adults with autism. We therefore suggest how these tools could be adapted to more effectively assess depression in adults with autism, and improve these individuals access to mental health assessment and support.

Modelling cytomegalovirus replication patterns in the human host: factors important for pathogenesis.

Human cytomegalovirus can cause a diverse range of diseases in different immunocompromised hosts. The pathogenic mechanisms underlying these diseases have not been fully elucidated, though the maximal viral load during infection is strongly correlated with the disease. However, concentrating on single viral load measures during infection ignores valuable information contained during the entire replication history up to the onset of disease. We use a statistical model that allows all viral load data sampled during infection to be analysed, and have applied it to four immunocompromised groups exhibiting five distinct cytomegalovirus-related diseases. The results show that for all diseases, peaks in viral load contribute less to disease progression than phases of low virus load with equal amount of viral turnover. The model accurately predicted the time of disease onset for fever, gastrointestinal disease and pneumonitis but not for hepatitis and retinitis, implying that other factors may be involved in the pathology of these diseases.

Inter- and intraobserver agreement in interpretation of CT features of medial coronoid process disease.

OBJECTIVES: To evaluate inter- and intraobserver reliability of the assessment of computed tomography features commonly used in the identification and classification of medial coronoid process disease and to assess inter- and intraobserver variability in the identification of the percentage ulna sclerosis from single transverse computed tomography images. METHODS: Eight observers, on two occasions, reviewed 84 standardised single transverse computed tomography images acquired at the level of the apex of the medial coronoid process. Observers assessed: medial coronoid process disease, coronoid process fragmentation, osteophytes, sclerosis grade and sclerosis delineation with normal bone defined using a sclerometer. Cohen's kappa and intraclass correlation coefficient were calculated. RESULTS: Inter-observer agreement was fair to moderate for identification of computed tomography changes consistent with medial coronoid process disease, moderate to almost perfect for fragmentation, and moderate for osteophyte detection. Agreement was poor for sclerosis grading. Percentage sclerosis measured with a sclerometer had moderate to almost perfect inter- and intraobserver agreement. CLINICAL SIGNIFICANCE: These findings suggest that subjective assessment of computed tomography images is less repeatable than more quantitative methods.

Lessons from the natural history of cytomegalovirus.

BACKGROUND: More than 90% of patients with HIV have been infected at some time with cytomegalovirus (CMV) and up to 40% of those with advanced HIV will develop CMV disease. The incidence of CMV disease is increasing but the prognosis for the patient remains poor. MONITORING FOR CMV: It is therefore important to monitor patients with low CD4+ counts in order to identify those most at risk of developing CMV disease and to treat them before the disease becomes established. Polymerase chain reaction (PCR) is probably the most effective and sensitive method of detecting CMV and a positive result is predictive for development of CMV disease; more than 80% of patients with CMV retinitis are CMV PCR-positive at the time of diagnosis. PCR can also detect the presence of CMV up to 14 months before the development of retinitis. TREATMENT OF CMV RETINITIS: In patients with detectable CMV, but no evidence of active infection, pre-emptive treatment with ganciclovir or valaciclovir has been shown to reduce the risk of developing retinitis in these high-risk patients. Such oral therapy, which is generally better tolerated than intravenous therapy and results in a better quality of life for the patient, is likely to be more effective at this stage whilst viral loads are low. CONCLUSIONS: CMV PCR can be used to prospectively monitor patients in order to identify those most at risk of developing CMV retinitis. If CMV infection is diagnosed early, while viral loads are still low, pre-emptive oral therapy can be instituted which will reduce the chances of developing retinitis in those patients most at risk.

Cytomegalovirus (CMV) viraemia detected by polymerase chain reaction identifies a group of HIV-positive patients at high risk of CMV disease.

BACKGROUND: Cytomegalovirus (CMV) disease is a major cause of morbidity in patients with HIV infection. Despite treatment, CMV retinitis causes substantial visual loss, especially in patients with CD4 cell counts below 50 x 10(6)/l. Although routine ophthalmological screening of these patients has been recommended, no controlled trials have evaluated how frequently it should be performed. The aim of this study was to assess whether CMV polymerase chain reaction (PCR) results could direct ophthalmological screening to patients at high risk of CMV retinitis. METHODS: In a prospective study of HIV-positive patients with CD4 cell counts below 50 x 10(6)/l, CMV viraemia was detected by qualitative PCR of whole blood. Patients who were CMV PCR-viraemic were allocated to monthly virological and ophthalmological follow-up; patients who were PCR-negative received 3-monthly virological and ophthalmological follow-up. CMV viral load was determined in all CMV-positive samples using a quantitative competitive PCR. RESULTS: Nineteen out of 97 patients developed CMV disease over the first 12 months of the study. Sixteen (59%) out of 27 patients who were CMV-positive developed disease compared with three (4%) out of 70 of patients who were PCR-negative (P = 0.0001). A positive CMV PCR result was significantly associated with the development of disease (P = 0.0001), with a relative hazard of 20.15 [95% confidence interval (CI), 5.80-69.98]. Median CMV viral load was significantly higher in those individuals who went on to develop CMV disease (P = 0.02). In PCR-positive patients, each 0.25 log10 increase in viral load increased the risk of disease (relative hazard, 1.37; 95% CI, 1.15-1.63; P = 0.0004). CONCLUSIONS: CMV PCR predicts the development of CMV disease and can be used to target ophthalmological resources to those patients at highest risk of retinitis. Asymptomatic patients who are PCR-positive represent a high-risk group in whom controlled trials of pre-emptive therapy could be conducted.

Cytomegalovirus retinitis in AIDS patients: influence of cytomegaloviral load on response to ganciclovir, time to recurrence and survival.

OBJECTIVES: Despite life-long maintenance therapy, cytomegalovirus (CMV) retinitis frequently progresses in patients with AIDS. Virological markers that could clarify pathogenesis and identify risk factors for progression are required. DESIGN AND METHODS: We prospectively recruited 45 patients with CMV retinitis. Blood and urine samples were collected before and after induction therapy, and on a monthly basis thereafter during routine medical and ophthalmological assessment, and at any time retinitis progressed. CMV load was measured by quantitative-competitive polymerase chain reaction (PCR). RESULTS: The median time to first progression of retinitis was 78 days and to death was 8.7 months. Eighty-five per cent of patients who were PCR-positive at diagnosis of retinitis became PCR-negative after 21 days of ganciclovir induction therapy. Six patients who remained PCR-positive after 21 days of treatment had a significantly higher CMV load at presentation (P = 0.005), and a shorter time to first progression of retinitis of 40 days. High CMV loads in blood at presentation were associated with a shorter time to progression (P = 0.16; relative hazard, 1.57) and a significantly shorter time to death (P = 0.004; relative hazard, 1.76). This significant relationship with survival remained after adjustment for potential confounding variables (CD4 count, age, method of drug administration). CONCLUSIONS: We conclude that CMV load in the blood of AIDS patients is an important factor in the pathogenesis of retinitis, and quantification of CMV could be used to both select patients for controlled clinical trials and to optimize individual anti-CMV induction therapy.

Cytomegalovirus polymerase chain reaction viraemia in patients receiving ganciclovir maintenance therapy for retinitis.

OBJECTIVES: To determine whether recurrence of polymerase chain reaction (PCR) viraemia during maintenance ganciclovir for cytomegalovirus (CMV) retinitis correlates with (i) CMV disease at a new anatomical site, (ii) progression of the presenting retinitis, or (iii) acquisition of genetic changes in gene UL97 associated with resistance to ganciclovir. DESIGN: A previously described cohort of 45 patients presenting with first episode retinitis was followed clinically using ophthalmoscopy and serial tests for PCR viraemia for a median of 7 months. CMV viral load and genetic markers of ganciclovir resistance were measured in PCR-positive samples. METHODS: PCR amplification of the glycoprotein B region of CMV and quantitative competitive PCR assays were employed. Genetic changes in UL97 were identified by sequencing/point mutation assay. RESULTS: PCR viraemia correlated significantly with new episodes of CMV disease (P=0.011) and a trend was seen for the association with progression of retinitis (P=0.07). Amongst the 14 patients PCR-positive during maintenance ganciclovir, 10 (71%) had genetic markers of resistance. None of these patients became PCR-negative in blood after reinduction ganciclovir therapy compared with three out of four without markers of resistance (P=0.022). CONCLUSIONS: CMV PCR viraemia correlated strongly with the development of new episodes of CMV disease. Most patients with progression of retinitis remained PCR-negative in blood, consistent with therapeutic failure due to poor intraocular penetration of ganciclovir. However, the minority who were PCR-positive in blood may have reinfected their eye, and frequently had markers of ganciclovir resistance. The implications of these findings for the management of patients with CMV disease are discussed.

Cytomegalovirus reactivation in patients infected with HIV: the use of polymerase chain reaction in prediction and management.

Patients with HIV are living longer now than in the past, and with a better quality of life. During the advanced stages of HIV infection patients are at risk of cytomegalovirus (CMV) reactivation and subsequently CMV disease. It is important to review the evidence on whether CMV reactivation leads to CMV disease and what the best methods are for detecting such a reactivation. CMV polymerase chain reaction (PCR) can be used qualitatively to predict CMV disease and quantitatively to predict a general increase in mortality. CMV PCR can also be used to direct either prophylaxis or pre-emptive therapy to those most at risk of CMV disease. CMV PCR should be an integral part of the decision-making process when treating both new patients with CMV retinitis and those with disease reactivation.

Gastrointestinal absorption of insulin-like growth factor in the mouse in the absence of salivary insulin-like growth factor binding protein.

Based on previous observations of the presence of both insulin-like growth factors I and II (IGF-I and IGF-II) in murine saliva (kerr et al., Biochem Pharmacol 49: 1521-1531, 1995), the saliva from BALB/c and Non-obese diabetic (NOD) mice was examined for the presence of insulin-like growth factor binding proteins (IGFBPs). Using a western-blot type ligand binding assay with 125I-labeled IGF-I, a series of binding proteins with molecular masses (M), between 25 and 45 kDa were detected in the sera, but not saliva, from both BALB/c and diabetic NOD mice. In the diabetic NOD mice, there were detectable changes in the concentrations of several of the IGFBPs relative to BALB/c mice. Using specific antibody to the binding proteins, one of these was identified as IGFBP-2. Gavage administration of [125I]IGFI indicated substantial uptake from the gastrointestinal tract and significant tissue distribution. There was an increase in serum concentrations of radiolabeled IGF-I in diabetic NOD mice over that in BALB/c mice but less recovered from most of the tissues. Intact 125I-labeled IGF-I was extracted and purified from various tissues, following gavage, and shown to retain biological activity. Thus, the uptake of biologically active IGFs from saliva would appear to take place independently of specific binding proteins.

Ultrastructure of Ebola virus particles in human liver.

Electron microscopy of tissues from two necropsies carried out in the Sudan on patients with Ebola virus infection identified virus particles in lung and spleen, but the main concentrations of Ebola particles were seen in liver sections. Viral precursor proteins and cores were found in functional liver cells, often aligned in membrane-bound aggregations. Complete virions, usually found only extracellularly, were mainly seen as long tubular forms, some without cores. Many tubular forms had 'enlarged heads' or 'spores' and some branched and torus forms were identified. The size and structure of the Ebola virus forms appear to be virtually indistinguishable from those of Marburg virus.

Yellow fever in the Gambia, 1978--1979: epidemiologic aspects with observations on the occurrence of orungo virus infections.

An epidemic of yellow fever (YF) occurred in the Gambia between May 1978 and January 1979. Retrospective case-finding methods and active surveillance led to the identification of 271 clinically suspected cases. A confirmatory or presumptive laboratory diagnosis was established in 94 cases. The earliest serologically documented case occurred in June 1978, at the extreme east of the Gambia. Small numbers of cases occurred in August and September. The epidemic peaked in October, and cases continued to occur at a diminishing rate through January, when a mass vaccination campaign was completed. The outbreak was largely confined to the eastern half of the country (MacCarthy Island and Upper River Divisions). In nine survey villages in this area (total population 1,531) the attack rate was 2.6--4.4%, with a mortality rate of 0.8%, and a case fatality rate of 19.4%. If these villages are representative of the total affected region, there may have been as many as 8,400 cases and 1,600 deaths during the outbreak. The disease incidence was highest in the 0- to 9-year age group (6.7%) and decreased with advancing age to 1.7% in persons over 40 years. Overall, 32.6% of survey village inhabitants had YF complement-fixing (CF) antibodies. The prevalence of antibody patterns indicating primary YF infection decreased with age, in concert with disease incidence. The overall inapparent:apparent infection ratio was 12:1. In persons with serological responses indicating flaviviral superinfection, the inapparent:apparent infection ratio was 10 times higher than in persons with primary YF infection. Sylvatic vectors of YF virus, principally Aedes furcifer-taylori and Ae. luteocephalus are believed to have been responsible for transmission, at least at the beginning of the outbreak. Eighty-four percent of wild monkeys shot in January 1979 had YF neutralizing antibodies, and 32% had CF antibodies. Domestic Aedes aegypti were absent or present at very low indices in many severely affected villages (see companion paper). In January, however, aegypti-borne YF 2.5 months into the dry season was documented by isolation of YF virus from a sick man and from this vector species in the absence of sylvatic vectors. Thus, in villages where the classical urban vector was abundant, interhuman transmission by Ae. aegypti occurred and continued into the dry season. A mass vaccination campaign, begun in December, was completed on 25 January, with over 95% coverage of the Gambian population. A seroconversion rate of 93% was determined in a group of vaccinees. This outbreak emphasizes the continuing public health importance of YF in West Africa and points out the need for inclusion of 17D YF vaccination in future programs of multiple immunication.

Development of a point mutation assay for the detection of human cytomegalovirus UL97 mutations associated with ganciclovir resistance.

A point mutation assay was developed to detect the quantitative prevalence of mutations at codons 460 (M to I; M to V), 520 (H to Q), 594 (A to V) and 595 (L to F; L to S) within the UL97 gene of human cytomegalovirus which segregate with ganciclovir resistance. Synthetic mixtures of wild-type and mutant plasmids containing the UL97 gene were amplified by nested polymerase chain reaction and the 700 base pair amplicon subsequently subjected to the point mutation assay. In plasmid reconstruction experiments, there was a high correlation between experimentally derived percentage mutant with the theoretical values. The assay was then used to assess the changes in the genetic composition of the UL97 gene in three patients on prolonged ganciclovir therapy. All three patients developed genotypic resistance against ganciclovir involving mutation at codon L595S, L595F and double mutation at codons L595F and M460I. In one patient, alteration of therapy to foscarnet did not affect the composition of UL97 and virus remained genotypically resistant to ganciclovir. In contrast, in two patients whose therapy was altered to cidofovir (HPMPC), repopulation with cytomegalovirus strains carrying the wild-type (ganciclovir-sensitive) codon at positions 595 and 460 occurred. The potential use of this assay for the rapid detection of cytomegalovirus resistance in patients on long-term ganciclovir therapy is discussed.