Prospective randomized trial of carotid endarterectomy with primary closure and patch angioplasty with saphenous vein, jugular vein, and polytetrafluoroethylene: long-term follow-up

PURPOSE: This study examines the long-term clinical outcome and the incidence of recurrent stenosis (> or = 50%) after carotid endarterectomy (CEA) with primary closure (PC) versus vein patch closure (VPC), saphenous (SVP), and jugular vein (JVP) and polytetrafluoroethylene patch closure (PTFE-P). METHODS: A total of 399 CEAs were randomized into the following groups: 135 PC, 134 PTFE-P, and 130 VPC (SVP alternating with JVP). Postoperative duplex ultrasound scans were performed at 1, 6, and 12 months and every year thereafter. The mean follow-up was 30 months with a range of 1 to 62 months, and demographic characteristics were similar in all groups. Kaplan-Meier analysis was used to estimate the risk of restenosis and the stroke-free survival. RESULTS: The incidence of ipsilateral stroke was 5% (seven of 135) for PC, 1% (one of 134) for PTFE-P, and 0% for VPC (PC vs VPC, p = 0.008; PC vs PTFE-P, p = 0.034). Seven strokes occurred in the perioperative period. All three groups had similar mortality rates. The cumulative stroke-free survival rate at 48 months was 82% for PC, 84% for PTFE-P, and 88% for VPC (p < 0.01 for PC vs PTFE-P or VPC). PC had a higher incidence of recurrent stenosis and occlusion (34%) than PTFE-P (2%) and VPC (9%) (SVP 9%, JVP 8%) (p < 0.001). PTFE-P had a lower recurrent stenosis rate than VPC (p < 0.045). Restenoses necessitating a redo CEA were also higher for PC (11%) than for PTFE-P (1%) and VPC (2%) (p < 0.001). Women with PC had a higher recurrent stenosis rate than men (46% vs 23%, p = 0.008). Kaplan-Meier analysis showed that freedom from recurrent stenosis at 48 months was 47% for PC, 84% for VPC, and 96% for PTFE-P (p < 0.001). The SVP and JVP results were comparable. The mean operative diameter of the internal carotid artery was similar in patients with or without restenosis. Significantly more late internal carotid artery dilatations occurred in the VPC group compared with the PC group. CONCLUSIONS: Patch closure (VPC or PTFE-P) is less likely than PC to cause perioperative stroke. Patching was also superior in lowering the incidence of late recurrent stenoses, especially in women.     

Sequence-based classification scheme for the genus Legionella targeting the mip gene

The identification and speciation of strains of Legionella is often difficult, and even the more successful chromatographic classification techniques have struggled to discriminate newly described species. A sequence-based genotypic classification scheme is reported, targeting approximately 700 nucleotide bases of the mip gene and utilizing gene amplification and direct amplicon sequencing. With the exception of Legionella geestiana, for which an amplicon was not produced, the scheme clearly and unambiguously discriminated among the remaining 39 Legionella species and correctly grouped 26 additional serogroup and reference strains within those species. Additionally, the genotypic classification of approximately 150 wild strains from several continents was consistent with their phenotypic classification, with the exception of a few strains where serological cross-reactivity was complex, potentially confusing the latter classification. Strains thought to represent currently uncharacterized species were also found to be genotypically unique. The scheme is technically simple for a laboratory with even basic molecular capabilities and equipment, if access to a sequencing laboratory is available.     

How can injuries be prevented in the World Cup soccer athlete?

In order to prevent soccer injuries, different risk factors have to be identified as intrinsic (e.g., joint stability or muscle imbalance) and extrinsic (e.g., equipment, turf, and rules risk factors). Some preventive measures are discussed in this article, such as shin guards, prophylactic braces and taping (or both), and proprioceptive training.     

Large gradient across a partially ligated left atrial appendage

The left atrial appendage is frequently ligated during mitral valve surgery to decrease the future risk of embolic events. The postoperative detection of a partially occluded left atrial appendage has previously been reported with the use of transesophageal echocardiography. We describe an unusual case in which Doppler echocardiography demonstrated a remarkably high-velocity jet emanating from a partially ligated left atrial appendage.     

Haemophilus ducreyi is susceptible to protegrin

Protegrins, potent antimicrobial peptides found in porcine leukocytes, have activity against the sexually transmitted pathogens Neisseria gonorrhoeae, Chlamydia trachomatis, and human immunodeficiency virus type 1. We tested synthetic protegrin 1 (PG-1) for activity against nine isolates of Haemophilus ducreyi, the etiologic agent of chancroid. The test organisms included CIP 542 (the type strain), 35000HP (a human-passaged variant of 35000), 35000HP-RSM2 (an isogenic D-glycero-D-manno-heptosyltransferase mutant of 35000HP), and six clinical isolates. The isolates were epidemiologically unrelated, represented three HindIII ribotypes, and had varying antimicrobial resistance patterns. In bactericidal assays, five isolates were rapidly killed by synthetic PG-1. In radial diffusion assays, all nine isolates were exquisitely sensitive to PG-1. These data highlight the potential of protegrins for development as topical agents to prevent many sexually transmitted diseases, including chancroid.     

Assessing the effects of cooperation bias and attrition in behavioral genetic research using data-weighting

Because twins and adoptees are a rare resource, they are often studied repeatedly over a period of many years. Differential attrition, and in some studies initial cooperation bias, have the potential to lead to serious biases to estimates of genetic and environmental parameters. Since non-response is often influenced by multiple binary or categorical sociodemographic variables, maximum-likelihood methods are not easily adapted to adjust for such effects. In this brief note we illustrate the use of data-weighting to assess the likely effects of cooperation bias or attrition both on measures of mean or prevalence, and on twin pair correlations or concordances, using data from the Australian twin panel 1981 survey and alcohol challenge studies. Participants in the alcohol challenge study were on average younger, more socially nonconforming, heavier drinkers, more likely to be unmarried, and less likely to report their religion as Other Protestant. Reweighting the alcohol challenge sample to have the same distribution on these variables as the Australian twin panel 1981 survey respondents confirmed that individuals who would feel very intoxicated after a challenge dose of alcohol were underrepresented in the study. However, pairwise data-weighting indicated that this cooperation bias was leading to only a slight underestimation of the importance of genetic effects on subjective intoxication.     

Pseudomonas aeruginosa as a cause of infectious diarrhoea

Pseudomonas aeruginosa is not generally considered a cause of infectious diarrhoea. However, it was the predominant organism isolated from the faeces of 23 unrelated, hospital outpatients investigated in the course of a year for persistent (> 1 week duration) diarrhoea. To investigate the possible aetiological role of P. aeruginosa, these patient histories were reviewed and a selection of their faecal isolates were investigated in vitro (n > or = 10) and in vivo (n = 2) for virulence. The patients had a mean age of 60 years, were receiving antibiotics and/or had an underlying illness. Extensive microbiological investigations identified no other potential or recognized enteropathogen in the faeces of 20 of these patients. More than 40% of the isolates tested were able to adhere to HEp-2 cells and exhibited twitching motility (type IV pili), properties indicative of their ability to colonize the human intestine. Cytotoxic activity was demonstrated in bacterium-free cell supernatants of over 80% of isolates; supernatants of four isolates tested in infant mice were weakly enterotoxigenic. Two isolates intragastrically inoculated into clindamycin pre-treated rats established persistent infections and induced signs and symptoms of enteritis. Overall these findings suggest that P. aeruginosa can cause diarrhoea particularly in immunodeficient individuals.     

Type-1 plasminogen-activator inhibitor -- conformational differences between latent, active, reactive-centre-cleaved and plasminogen-activator-complexed forms, as probed by proteolytic susceptibility

We have analysed the susceptibility of latent, active, reactive-centre-cleaved and plasminogen-activator-complexed type-1 plasminogen-activator inhibitor (PAI-1) to the non-target proteinases trypsin, endoproteinase Asp-N, proteinase K and subtilisin. This analysis has allowed us to detect conformational differences between the different forms of PAI-1 outside the reactive-centre loop and beta-sheet A. Proteinase-hypersensitive sites were clustered in three regions. Firstly, susceptibility was observed in the region around alpha-helix E, beta-strand 1A, and the flanking loops, which are believed to form flexible joints during movements of beta-sheet A. Secondly, hypersensitive sites were observed in the loop between alpha-helix I and beta-strand 5A. Thirdly, the gate region, encompassing beta-strands 3C and 4C, was highly susceptible to trypsin in latent PAI-1, but not in the other conformations. The digestion patterns differed among all four forms of PAI-1, indicating that each represents a unique conformation. The differential proteolytic susceptibility of the flexible-joint region may be coupled to the differential affinity to vitronectin, binding in the same region. The analysis also allowed detection of conformational differences between reactive-centre-cleaved forms produced under different solvent conditions. The digestion pattern of plasminogen-activator-complexed PAI-1 was different from that of active PAI-1, but indistinguishable from that of one of the reactive-centre-cleaved forms, as the complexed and this particular cleaved PAI-1 were completely resistant to all the non-target proteinases tested. This observation is in agreement with the notion that complex formation involves reactive-centre cleavage and a large degree of insertion of the reactive-centre loop into beta-sheet A. Our analysis has allowed the identification of some flexible regions that appear to be implicated in the conformational changes during the movements of beta-sheet A and during the inhibitory reaction of serpins with their target proteinases.     

Association of human herpes virus 6 (HHV-6) with multiple sclerosis: increased IgM response to HHV-6 early antigen and detection of serum HHV-6 DNA

Viruses have long been suggested to be involved in the etiology of multiple sclerosis (MS). This suggestion is based on (1) epidemiological evidence of childhood exposure to infectious agents and increase in disease exacerbations with viral infection; (2) geographic association of disease susceptibility with evidence of MS clustering; (3) evidence that migration to and from high-risk areas influences the likelihood of developing MS; (4) abnormal immune responses to a variety of viruses; and (5) analogy with animal models and other human diseases in which viruses can cause diseases with long incubation periods, a relapsing-remitting course, and demyelination. Many of these studies involve the demonstration of increased antibody titers to a particular virus, whereas some describe isolation of virus from MS material. However, no virus to date has been definitively associated with this disease. Recently, human herpesvirus 6 (HHV-6), a newly described beta-herpes virus that shares homology with cytomegalovirus (CMV), has been reported to be present in active MS plaques. In order to extend these observations, we have demonstrated increased IgM serum antibody responses to HHV-6 early antigen (p41/38) in patients with relapsing-remitting MS (RRMS), compared with patients with chronic progressive MS (CPMS), patients with other neurologic disease (OND), patients with other autoimmune disease (OID), and normal controls. Given the ubiquitous nature of this virus and the challenging precedent of correlating antiviral antibodies with disease association, these antibody studies have been supported by the detection of HHV-6 DNA from samples of MS serum as a marker of active viral infection.