Prophylactic Use of Implantable Cardioverter-Defibrillators in the Prevention of Sudden Cardiac Death in Dialysis Patients.

BACKGROUND: Patients with end-stage renal disease who are undergoing dialysis are reported to be at high risk of sudden cardiac death (SCD), and to date, no therapy has been shown to be effective in reducing this risk. The feasibility and value of prophylactic implantable cardioverter-defibrillator (ICD) implantation to prevent SCD is uncertain. METHODS: We conducted the ICD2 trial (Implantable Cardioverter-Defibrillator in Dialysis Patients), a prospective, randomized, controlled study investigating the value and safety of ICD implantation to prevent SCD in 200 patients on dialysis with a left ventricular ejection fraction ≥35%, after adequate screening and optimization of other treatments. The primary end point was SCD. Secondary end points were all-cause mortality and ICD-related complications. RESULTS: The trial was stopped as per the recommendation of the data and safety monitoring board for futility reasons after inclusion of 188 patients, 97 in the ICD group and 91 in the control group. The median duration of follow-up was 6.8 years (interquartile range, 3.8-8.8 years). SCD occurred in 19 of 188 cases (10.1%), 11 of 97 in the ICD group and 8 of 91 in the control group. The cumulative SCD incidence at 5 years was 9.7% (95% CI, 3.3%-16.2%) in the ICD group and 7.9% (95% CI, 1.7-14.0%) in the control group, resulting in a hazard ratio of 1.32 (95% CI, 0.53-3.29; P=0.55). Overall, 99 of 188 patients died (52.7%), 52 in the ICD group and 47 in the control group. Five-year survival probability was 50.6% (95% CI, 39.8%-61.5%) in the ICD group and 54.5% (95% CI, 43.0-66.0%) in the control group, resulting in a hazard ratio of 1.02 (95% CI, 0.69-1.52; P=0.92). Among 80 patients who received an ICD, 25 adverse events related to ICD implantation occurred. CONCLUSIONS: In a well-screened and well-treated population undergoing dialysis, prophylactic ICD therapy did not reduce the rate of SCD or all-cause mortality, which remained high. CLINICAL TRIAL REGISTRATION: URL: http://www.controlled-trials.com . Unique identifier: ISRCTN20479861.

RHD genotype and zygosity analysis in the Chinese Southern Han D+, D- and D variant donors using the multiplex ligation-dependent probe amplification assay.

BACKGROUND AND OBJECTIVES: Several comprehensive genotyping platforms for determining red blood cell (RBC) antigens have been established and validated for use in the Caucasian and Black populations, but not for the Chinese. The multiplex ligation-dependent probe amplification (MLPA) assay was validated for RHD genotyping in the Chinese. MATERIALS AND METHODS: The blood samples of 200 D+, 200 D- and 62 D variant Chinese donors were collected. RhD antigen was routinely typed by serological method. D variant phenotype was determined by an anti-D panel (D-Screen), when RBCs were available. The RHD genotype and its zygosity were analysed with the RH-MLPA technique. When the MLPA was unable to identify a RHD variant, direct sequencing of all exons of the RHD gene was performed. RESULTS: In 200 D+ donors, DD (168/200, 84%), D (12/200, 6%), DDD genotype (1/200) and D variant allele carriers (19/200, 9·5%) were found. In 200 D- donors, six reported RHD alleles, RHD*01EL.01, RHD*01N.03, RHD*01N.05, RHD*01N.16, RHD*DFR2 and RHD*weak partial 15 and one novel RHD*1154T allele were identified in 36·5% (73/200) of them. In 62 D variant donors, three novel RHD alleles, RHD*79_81delCTC, RHD*710T and RHD*689A, and twelve reported alleles, RHD*DVI.3, RHD*weak partial 15, RHD*DVI.4, RHD*01EL.01, RHD*01N.03, RHD*DLO, RHD*DV.5, RHD*D-CE(2-10), RHD*730C, RHD*weak D type 25, 33 and 72, were identified, either alone or in combination. CONCLUSION: The RH-MLPA assay correctly identified the common RHD variant alleles in the Chinese population. However, DNA sequencing was required to identify certain alleles; probes to detect these alleles should be added into the assay.

Using the Fly-FUCCI System for the Live Analysis of Cell Cycle Dynamics in Cultured Drosophila Cells.

Cultured Drosophila cells are an attractive system for live imaging experiments, as this cell type is not very demanding in terms of temperature and media composition. Moreover, cultured Drosophila cell lines are very responsive to RNAi without being prone to off-target effects, and thus have become important for use in high-content screening. We have developed a fly-specific fluorescent, ubiquitination-based cell cycle indicator (FUCCI) system that enables faithful detection of G1, S, and G2 phases, and is thus a powerful tool for the analysis of cell cycle dynamics in living or fixed cells. Here, we describe a protocol for the generation of cell lines stably expressing the Fly-FUCCI sensors, followed by a description of how these cell lines can be employed in studies of cell cycle oscillation using live microscopy.

Assessment of p53 and ATM functionality in chronic lymphocytic leukemia by multiplex ligation-dependent probe amplification.

The ATM-p53 DNA-damage response (DDR) pathway has a crucial role in chemoresistance in CLL, as indicated by the adverse prognostic impact of genetic aberrations of TP53 and ATM. Identifying and distinguishing TP53 and ATM functional defects has become relevant as epigenetic and posttranscriptional dysregulation of the ATM/p53 axis is increasingly being recognized as the underlying cause of chemoresistance. Also, specific treatments sensitizing TP53- or ATM-deficient CLL cells are emerging. We therefore developed a new ATM-p53 functional assay with the aim to (i) identify and (ii) distinguish abnormalities of TP53 versus ATM and (iii) enable the identification of additional defects in the ATM-p53 pathway. Reversed transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) was used to measure ATM and/or p53-dependent genes at the RNA level following DNA damage using irradiation. Here, we showed that this assay is able to identify and distinguish three subgroups of CLL tumors (i.e., TP53-defective, ATM-defective and WT) and is also able to detect additional samples with a defective DDR, without molecular aberrations in TP53 and/or ATM. These findings make the ATM-p53 RT-MLPA functional assay a promising prognostic tool for predicting treatment responses in CLL.

Identifying and characterizing a second structural domain of protein disulfide isomerase.

Recent protein engineering studies have confirmed the multidomain nature of protein disulfide isomerase previously suggested on the basis of analysis of its amino acid sequence. The boundaries of three domains, denoted a, a' and b, have been determined, and each domain has been expressed as an individual soluble folded protein. In this report, the boundaries of the final structural domain, b', are defined by a combination of restricted proteolysis and protein engineering approaches to complete our understanding of the domain organization of PDI. Using these data an optimized polypeptide construct has been prepared and characterized with a view to further structural and functional studies.

Mild closed head injury in children compared to traumatic fractured bone; neurobehavioural sequelae in daily life 2 years after the accident.

UNLABELLED: Two years after an accident resulting in either a mild head injury or a fractured bone, two groups of 22 children each, aged 4-14 years, were examined for the existence of any neurobehavioural symptoms by means of a standardized questionnaire filled out by their caretakers. Selection of the children was based on reports of the Accident and Emergency Department in 1 year. Significantly more symptoms were reported after mild head injury. The main symptoms reported were headache, dizziness, fatigue and memory problems. The total number of symptoms in the children with mild head injury exceeded four times this in the group of children with a fractured bone. CONCLUSION: Even 2 years after a mild head injury there are still residual symptoms in daily life.

Association of kettin with actin in the Z-disc of insect flight muscle.

The Z-discs of insect muscle contain kettin, a modular protein of 500-700 kDa. The Drosophila protein is made up of a chain of immunoglobulin (Ig) domains separated by linker sequences. Kettin differs from other modular muscle proteins of the Ig superfamily in binding to thin filaments rather than thick filaments. Kettin isolated from Lethocerus (waterbug) muscle is an elongated molecule 180 nm long, which binds to F-actin with high affinity (Kd=1.2 nM) and a stoichiometry of one Ig domain per actin protomer. Competition between kettin and tropomyosin for binding to actin excludes tropomyosin from the Z-disc. In contrast, kettin and alpha-actinin bind simultaneously to actin, which would reinforce the Z-disc lattice. In vitro, kettin promotes the antiparallel association of actin filaments, and a similar process may occur in the developing sarcomere: actin filaments interdigitate in an antiparallel fashion in the Z-disc with the N terminus of kettin within the Z-disc, and the C terminus some way outside. We propose a model for the association of kettin with actin in which the molecule follows the genetic helix of actin and Ig domains, separated by linker sequences, bind to each actin protomer.

The functional properties of DsbG, a thiol-disulfide oxidoreductase from the periplasm of Escherichia coli.

Genetic studies have recently identified DsbG, a new member of the dsb group of redox proteins, which catalyze protein disulfide bond formation in the periplasm of Escherichia coli. We now demonstrate that DsbG functions primarily as an oxidant during protein disulfide bond formation, which is consistent with the low stability of its active site disulfide bond. There are indications, however, that the substrate range of DsbG may be narrower than the other periplasmic oxidative enzymes, DsbA and DsbC. Our observations further elaborate the pathway of disulfide bond formation in E. coli.

Infected aneurysm of the abdominal aorta due to Listeria monocytogenes.

A 79-yr-old man was known for a year with a deteriorating clinical condition, vague abdominal complaints and an elevated erythrocyte sedimentation rate; he was afebrile. Extensive evaluation revealed no cause for his progressive disease. Eventually an infected aneurysm of the abdominal aorta was diagnosed, from which Listeria monocytogenes was cultured. After resection of the aneurysm the patient recovered initially very well. Regrettably, therapy-resistant chylous ascites developed, and the patient died due to surgical complications following a second laparotomy. Infected aortic aneurysms can present as an insidious disease, which may have catastrophic consequences if undiagnosed. A high index of suspicion is required to make a correct diagnosis. L. monocytogenes is an emerging, food-borne pathogen that can cause a wide spectrum of human diseases.

Familial IgG subclass imbalance, anti-SS-A antibodies and third-trimester foetal death.

Foetal heart block occurred in the second pregnancy of an apparently healthy 23-yr-old woman. Her mother and sister were known for 10 yr with hypergammaglobulinaemia which was due to a disproportionate polyclonal elevation of serum IgG1 and with a high titre of rheumatoid factors. No associated disease was obvious. A third-trimester foetal death had occurred with each of these patients. In the sera of these three women circulating anti-SS-A (Ro) antibodies were detected, which are known to be associated with congenital heart block. IgG subclass imbalance, consisting of a disproportionate polyclonal elevation of IgG1, has been recognised as being associated with a characteristic autoantibody pattern. Familial occurrence of this syndrome as such has hitherto not been reported.

Beware of the dog: meningitis in a splenectomised woman.

Purulent meningitis was diagnosed in a 75-yr-old splenectomised woman nine days after a dog bite. The original wound was apparently uninflamed. The causative microorganism proved to be a dysgonic fermenter 2 (DF-2) bacterium (renamed Capnocythophaga canimorsus). This is a recently recognised Gram-negative bacterium, belonging to the normal canine mouth flora, to which asplenic individuals seem to be particularly susceptible.

Elevated level of IgA gliadin antibodies in patients with rheumatoid arthritis.

The possibility that dietary antigens contribute to the pathogenesis of rheumatoid arthritis (RA) has been proposed. Moreover, occasional patients have been described in whom coeliac disease and RA coincide. Furthermore, most RA patients are treated with non-steroidal anti-inflammatory drugs (NSAIDs), which are known to increase gut permeability. For these reasons antibodies against gliadin were measured in a group of 43 patients with rheumatoid arthritis (RA) and a group of 43 age- and sex-matched controls. The median IgA antigliadin ELISA index was 7.1 (range 2.1-22.4) for the RA group and 3.1 (range 0.3-34.9) for the controls (p = 0.0001). The median IgG and IgM antigliadin indexes for the RA group didn't differ significantly from those of the controls. In the RA group, the level of antigliadin antibodies did not correlate with the daily dose of NSAIDs. The elevated IgA antigliadin titre in the RA group might be ascribed to the use of NSAIDs, which are harmful to the gut, but the immunological trigger effect of gluten cannot be ruled out.