Paroxysmal atrial fibrillation occurs often in cryptogenic ischaemic stroke. Final results from the SURPRISE study.

BACKGROUND AND PURPOSE: Atrial fibrillation (AF) increases the risk of stroke fourfold and is associated with a poor clinical outcome. Despite work-up in compliance with guidelines, up to one-third of patients have cryptogenic stroke (CS). The prevalence of asymptomatic paroxysmal atrial fibrillation (PAF) in CS remains unknown. The SURPRISE project aimed at determining this rate using long-term cardiac monitoring. METHODS: Patients with CS after protocolled work-up including electrocardiography (ECG) and telemetry were included after informed consent. An implantable loop recorder (ILR) was implanted subcutaneously. PAF was defined by events of atrial arrhythmia >2 min with a correlating one-lead ECG confirming the diagnosis. RESULTS: Eighty-five patients were monitored for a mean of 569 days (SD ±310). PAF was documented in 18 patients (20.7%) during the study period and detected by ILR in 14 patients (16.1%). In three patients PAF was detected by other methods before or after monitoring and was undiscovered due to device sensitivity in one case. The first event of PAF was documented at a mean of 109 days (SD ±48) after stroke onset. PAF was asymptomatic in all cases and occurred in episodes lasting predominantly between 1 and 4 h. Four recurrent strokes were observed, three in patients with PAF; all three patients were on oral anticoagulation (OAC). CONCLUSIONS: One in five patients with CS had PAF, which occurred at low burden and long after stroke. Future studies should determine the role of implantable cardiac monitors after stroke and determine the potential therapeutic benefit of OAC treatment of patients with PAF.

Role of Ced-3/ICE-family proteases in staurosporine-induced programmed cell death.

In the accompanying paper by Weil et al. (1996) we show that staurosporine (STS), in the presence of cycloheximide (CHX) to inhibit protein synthesis, induces apoptotic cell death in a large variety of nucleated mammalian cell types, suggesting that all nucleated mammalian cells constitutively express all of the proteins required to undergo programmed cell death (PCD). The reliability of that conclusion depends on the evidence that STS-induced, and (STS + CHS)-induced, cell deaths are bona fide examples of PCD. There is rapidly accumulating evidence that some members of the Ced-3/Interleukin-1 beta converting enzyme (ICE) family of cysteine proteases are part of the basic machinery of PCD. Here we show that Z-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), a cell-permeable, irreversible, tripeptide inhibitor of some of these proteases, suppresses STS-induced and (STS + CHX)-induced cell death in a wide variety of mammalian cell types, including anucleate cytoplasts, providing strong evidence that these are all bona fide examples of PCD. We show that the Ced-3/ICE family member CPP32 becomes activated in STS-induced PCD, and that Bcl-2 inhibits this activation. Most important, we show that, in some cells at least, one or more CPP32-family members, but not ICE itself, is required for STS-induced PCD. Finally, we show that zVAD-fmk suppresses PCD in the interdigital webs in developing mouse paws and blocks the removal of web tissue during digit development, suggesting that this inhibition will be a useful tool for investigating the roles of PCD in various developmental processes.

Ultraviolet radiation and the risks of cutaneous malignant melanoma and non-melanoma skin cancer: perceptions and behaviours of Danish and American adolescents.

The highest prevalence rates of skin malignancy in the northern hemisphere occur in Scandinavia and the United States (USA). Most Danes and Americans receive 50% of their lifetime ultraviolet (UV) radiation before the age of 21, making it important to address sun exposure risks with adolescents. The project was undertaken to determine differences between Danish and American adolescents in knowledge of sun exposure and skin malignancy, activities accounting for sun exposure, and means used for sun protection. Questionnaires regarding skin cancer and sun exposure were distributed to 674 secondary school age students in Hilleroed, Denmark, and to 483 similarly aged students in Winston-Salem, North Carolina, USA. Differences in responses between and within groups were compared. American adolescents had more knowledge of the characteristics and malignant potential of melanoma than did Danish adolescents. Danish youth and females from both countries were significantly more likely to engage in sunbathing and tanning bed use. Black Danish students reported significantly more sunburn and were more likely to sunbathe or use a tanning bed than were black American students. Danish students were more likely than Americans to use sunscreen, however, Americans were more likely to apply sun protective factor (SPF) 15 or greater. In conclusion, given that sunbathing and tanning bed use are associated with the development of precancerous lesions and skin malignancy, Danish teens are at increased risk. The rates of skin malignancy are relatively high in Scandinavia and efforts to improve understanding of exposure and cancer risks should be undertaken in adolescents.

Clinical significance of abnormal T waves in patients with non-ST-segment elevation acute coronary syndromes.

T-wave abnormalities are common electrocardiographic occurrences in patients with non-ST-segment elevation acute coronary syndromes. Although these abnormalities are considered relatively benign, physicians use them to guide therapies. The study objective was to examine the prognostic predictive information of T-wave abnormalities in the setting of unstable coronary artery disease. The T-wave abnormality criterion was based on a new set of normal T-wave amplitude limits differentiated by gender, age, electrocardiographic lead, and QRS axis. Four hundred sixty-eight patients suspected of an acute ischemic incident and considered ineligible for reperfusion therapy were included. Thirteen categories of T-wave abnormalities were tested prospectively. The primary 30-day end point was the combination of refractory angina, myocardial infarction, or death. Quantitative T-wave analysis in an electrocardiographic core laboratory revealed 6 of 13 prespecified categories of T-wave abnormalities that were significantly associated with an adverse outcome. T-wave abnormalities had no prognostic value when ST-segment depression was also present, but this occurred in only 7.9% of patients. T-wave abnormalities as the sole manifestation of ischemia were common (74.4%). Patients with abnormal T waves in > or =1 of 6 selected abnormality categories (70.3%) had a significantly higher risk of death, acute myocardial infarction, and refractory angina (11% vs 3%; p = 0.018). Thus, T-wave abnormalities in patients presenting with non-ST-segment elevation acute coronary syndromes are common and should not automatically be regarded as benign phenomena. Quantitative T- wave analysis provides optimal risk stratification.

Comparison of multiple typing methods for Aspergillus fumigatus.

As part of studies on the spread of infections, risk factors and prevention, several typing methods were developed to investigate the epidemiology of Aspergillus fumigatus. In the present study, 52 clinical isolates of A. fumigatus from 12 airway specimens from patients with invasive aspergillosis (hospitalized in three different centres) were characterized by short tandem repeat (STR) typing and multilocus sequence typing (MLST). These isolates were previously typed by random amplified polymorphic DNA (RAPD), sequence-specific DNA polymorphism (SSDP), microsatellite polymorphism (MSP) and multilocus enzyme electrophoresis (MLEE). STR typing identified 30 genotypes and, for most patients, all isolates were grouped in one cluster of the unweighted pair group method with arithmetic mean dendrogram. Using MLST, 16 genotypes were identified among 50 isolates, while two isolates appeared untypeable. RAPD, MSP, SSDP and MLEE allowed identification of eight, 14, nine and eight genotypes, respectively. Combining the results of these methods led to the delineation of 25 genotypes and a similar clustering pattern as with STR typing. In general, STR typing led to similar results to the previous combination of RAPD, SSDP, MSP and MLEE, but had a higher resolution, whereas MLST was less discriminatory and resulted in a totally different clustering pattern. Therefore, this study suggests the use of STR typing for research concerning the local epidemiology of A. fumigatus, which requires a high discriminatory power.

Multilocus sequence typing of the pathogenic fungus Aspergillus fumigatus.

A multilocus sequence typing (MLST) scheme was devised for Aspergillus fumigatus. The system involved sequencing seven gene fragments and was applied to a panel of 100 isolates of A. fumigatus from diverse sources. Thirty different sequence types were found among the 100 isolates, and 93% of the isolates differed from the other isolates by only one allele sequence, forming a single clonal cluster as indicated by the eBURST algorithm. The discriminatory power of the MLST method was only 0.93. These results strongly indicate that A. fumigatus is a species of a relatively recent origin, with low levels of sequence dissimilarity. Typing methods based on variable numbers of tandem repeats offer higher levels of strain discrimination. Mating type data for the 100 isolates showed that 71 isolates were type MAT1-2 and 29 isolates were MAT1-1.

Candida albicans strain maintenance, replacement, and microvariation demonstrated by multilocus sequence typing.

We typed 165 Candida albicans isolates from 44 different sources by multilocus sequence typing (MLST) and ABC typing of rRNA genes and determined their homozygosity or heterozygosity at the mating-type-like locus (MTL). The isolates represented pairs or larger sets from individual sources, which allowed the determination of strain diversity within patients. A comparison of replicate sequence data determined a reproducibility threshold for regarding isolates as MLST indistinguishable. For 36 isolate sets, MLST and ABC typing showed indistinguishable or highly related strain types among isolates from different sites or from the same site at different times from each patient. This observation included 11 sets with at least one isolate from a blood culture and a nonsterile site from the same patient. For one patient, strain replacement was evidenced in the form of two sets of isolates from different hospital admissions where the strain types within each set were nearly identical but where the two sets differed both by MLST and ABC typing. MLST therefore confirms the existing view of C. albicans strain carriage. Microvariation, evidenced as small differences between MLST types, resulted in most instances from a loss of heterozygosity at one or more of the sequenced loci. Among isolate sets that showed major strain type differences, some isolates could be excluded as likely examples of handling errors during storage. However, for a minority of isolates, intermittent differences in ABC type for tightly clustered MLST types and intermittent appearances of MTL homozygosity lead us to propose that some C. albicans isolates, or all isolates under yet-to-be-determined conditions, maintain a high level of genetic diversity by mechanisms such as recombination, gene conversion, or chromosomal ploidy change.