Quality of life in patients with small abdominal aortic aneurysm: the effect of early endovascular repair versus surveillance in the CAESAR trial

OBJECTIVE

To evaluate and compare changes over time in health-related quality of life reported by patients with small (4.1-5.4 cm) abdominal aortic aneurysms (AAAs) undergoing endovascular aortic aneurysm repair (EVAR) or surveillance.

METHODS

Participants were randomly assigned to receive either early EVAR or surveillance within a multicentre, randomised clinical trial on small AAA (Comparison of surveillance vs. Aortic Endografting for Small Aneurysm Repair, CAESAR). Patient-reported health-related quality of life was assessed before randomisation, at 6 months and yearly thereafter using the Short Form 36 (SF-36) Health Survey.

RESULTS

Between 2004 and 2008, 360 patients (345 males, mean age 68.9 years) were randomised, 182 to early EVAR and 178 to surveillance. There was one perioperative death. Mean follow-up was 31.8 months. No significant difference in survival was found. At baseline, comparable quality of life scores were recorded in both treatment groups: Total SF-36: 73.0 versus 75.5 (p = 0.18), Physical domain: 71.4 versus 73.3 (p = 0.33); Mental health domain: 70.9 versus 72.7 (p = 0.33), in the EVAR arm versus the surveillance arm, respectively. Six months after randomisation, Total SF-36 and Physical and Mental domain scores were all significantly higher with respect to baseline in the EVAR group, while patients of the surveillance group scored lower. The differences between EVAR and surveillance arms in score changes at 6 months were significant and in favour of EVAR: Total score: difference 5.4; p = 0.0017; Physical: difference 3.8; p = 0.02; and Mental: difference 6.0; p = 0.0005. Differences between EVAR and surveillance diminished over time. At the last assessment, patients in both groups had decreased scores with a significant drop with respect to the baseline (-3.9 in EVAR, -6.3 in surveillance). There were no significant differences between the EVAR and surveillance arms: Total score: p = 0.25; Physical: p = 0.47; and Mental: p = 0.38.

CONCLUSIONS

Patients with small AAA under surveillance compared with early EVAR had significant impaired functional health at 6 months after assignment. After a mean of 31.8 months, SF-36 health-related quality of life in patients allocated to early EVAR and surveillance was similar.

Functional ability in patients with critical limb ischaemia is unaffected by successful revascularisation

OBJECTIVE

Patient- and society-oriented measures of outcome have a critical role in determining the effectiveness of any treatment in patients with critical limb ischaemia (CLI). In particular, the impact of an intervention on patient's dependency and functional performance is relevant but is largely unknown. The aim of the study was to investigate whether the limitations encountered in the activities of daily living (ADLs) measured with the Katz Index (KI) in patients with CLI were changed by the treatment.

METHODS

During the period 2006-2008, 248 consecutive patients undergoing repair for CLI were investigated with an ADL questionnaire for assessing KI before and after a mean of 16.19 months from treatment. Changes in KI were stratified by type of treatment and outcome.

RESULTS

There were 165 males and 83 females, mean age 73.3 ± 8.3 years; 125 patients showed tissue loss and 123 rest pain alone, 98 received surgical bypass and 150 endovascular repair. Pre-operative KI mean was 10.42. At the post-operative assessment, there was significant worsening in patients' functional outcome (mean KI decreased to 9.78) despite relief of pain (81.5%), tissue healing (72%), good vessel patency (83.8%) and low amputation rate (9.7%). Deterioration of KI was not significantly higher in patients undergoing endovascular repair. Patients receiving major amputation started with worse pre-operative functional score (KI mean 9.42) and did further deteriorate (KI mean 7.71) after demolition surgery. However, patients who received successful revascularisation showed deterioration in the dependence index.

CONCLUSIONS

Successful vascular treatment is not associated with improved functional ability in patients with CLI, especially when already highly dependent in their activities. Large nationwide preventive and educational programmes should be implemented to prevent irreversible and severe health deterioration in populations with CLI.

Cognitive performance in elderly patients undergoing carotid endarterectomy or carotid artery stenting: a twelve-month follow-up study

BACKGROUND

It is still a matter of debate if and to what extent carotid endarterectomy (CEA) and carotid artery stenting (CAS) impair cognitive functioning in the elderly.

METHODS

We conducted a nonrandomized clinical trial on subjects with asymptomatic carotid artery stenosis comparing CEA (n = 28; 24 males and 4 females; 72.6 +/- 5.8 years old) with CAS (n = 29; 17 males and 12 females; 75.1 +/- 5.7 years old). Cognition, mood and functional status were evaluated by a broad spectrum of tests performed on the day prior to carotid reopening as well as 3 and 12 months after.

RESULTS

No significant differences in scores on cognitive tests including the Babcock story recall test and Rey's auditory verbal learning test (memory), category naming test (verbal fluency), trail-making test parts A and B (attention and executive function) and controlled oral word association test (executive functioning) were observed 3 and 12 months after carotid reopening independent of the technique used. Only scores on the copy drawing test (visuospatial and constructional abilities) slightly but significantly (p < 0.05) worsened in the CAS group 12 months after the intervention. No significant differences between the CEA and CAS groups were detected regarding mood and functional status after 3 and 12 months.

CONCLUSIONS

CEA and CAS seem to be safe procedures in elderly patients in terms of cognitive, mood and functional status in the short and long term. CAS might be preferred for the shorter hospital stay, but further studies with a larger number of old and oldest old subjects with a longer follow-up are needed to better understand the cost-effectiveness of both treatments.

Antitumour response of a double mutant of staphylococcal enterotoxin C2 with the decreased affinity for MHC class II molecule

Staphylococcal enterotoxin C2 (SEC2) is one of the most potent known activators of human T lymphocytes, and recombinant SEC2 shows promising clinical values, but SEC2 can cause food poisoning and toxic shock syndrome in vivo. In this study, site-directed mutagenesis has been used to introduce alanine substitutions at Phe144 and Leu45 in the molecule. The mutant genes were cloned and expressed, and the corresponding proteins were purified by nickel agarose affinity chromatography. We found that the SEC2 mutant proteins could stimulate the proliferation of human peripheral blood lymphocytes and inhibit the growth of tumour cells as native SEC2. Furthermore, flow cytometry assay showed that mSEC2(F44A, L45A) drastically reduced the ability of the toxin to bind to MHC class II. Physiological parameters revealed that mSEC2(F44A, L45A) reduced significantly rat temperature compared with native SEC2 in vivo. Our results clearly suggest that this genetically modified SEC2 protein is less toxic and justifies its further development as a new, safer antitumour superantigen to prevent SEC2 intoxication.

Endoleak after endovascular aortic repair: classification, diagnosis and management following endovascular thoracic and abdominal aortic repair

Endoleak is a common and unique complication of endovascular aortic repair (EVAR) and its persistence represents a failure of the endovascular treatment. Accurate detection and classification is essential for the proper management since the method of endoleak treatment is determined by the different source. In general, high-pressure leaks (type I and type III) require urgent management because of the relatively high short-term risk of sac rupture. Although precise differentiation between type I and type III endoleaks may not be possible at cross- sectional imaging, differentiation is often unnecessary because both lesions are considered high-risk and require angiographic evaluation and subsequent treatment. Low-pressure lesions (types II and V or endotension) are considered less urgent but may warrant continued endovascular evaluation if there is impending growth of the aneurysm sac or if the patient presents with symptoms. Once detected, endoleaks warranting correction (all type I and III; persistent endotension and type II associated with aneurysm enlargement) are usually treated by endovascular route. A variety of techniques including extension endografts or cuff, balloon angioplasty, bare stents and a combination of transvascular and direct sac puncture embolization techniques has allowed to treat the vast majority of these endoleaks without conversion to open surgical repair. Type II endoleak continues to be the most common but also the most controversial in terms of evaluation, the need of treatment, and methods of treatment. Careful and rigorous postoperative lifelong follow-up with computed tomography (CT) and high quality imaging continue to be essential for all patients after EVAR.

Yin Yang 1 regulates the transcriptional activity of androgen receptor

The multifunctional protein Yin Yang 1 (YY1) plays an important role in epigenetic regulation of gene expression. YY1 is highly expressed in various types of cancers, including prostate cancer. Currently, the mechanism underlying the functional role of YY1 in prostate tumorigenesis remains unclear. In this report, we investigated the functional interplay between YY1 and androgen receptor (AR), and the effect of YY1 on AR-mediated transcription. We found that YY1 physically interacts with AR both in a cell-free system and in cultured cells. YY1 is required for the optimal transcriptional activity of AR in promoting the transcription of the prostate specific antigen (PSA) promoter. However, ectopic YY1 expression in LNCaP cells did not further enhance the reporter driven by the PSA promoter, suggesting an optimal level of YY1 is already established in prostate tumor cells. Consistently, YY1 depletion in LNCaP cells reduced endogenous PSA levels, but overexpressed YY1 did not significantly increase PSA expression. We also observed that YY1-AR interaction is essential to YY1-mediated transcription activity of AR and YY1 is a necessary component in the complex binding to the androgen response element (ARE). Thus, our study demonstrates that YY1 interacts with AR and regulates its transcriptional activity.

Different types of thoracic endografts

The emerging role of stent-graft strategies for the management of thoracic aortic diseases has attracted growing acceptance, especially in considering the sobering results of open repair in thoracic high-risk settings (e.g., acute dissection, trauma, rupture). Aortic endograft technology for thoracic diseases has rapidly improved after the early use of first generation devices, and the new models show very promising early and mid-term success rates. To date there is no evidence of the superiority of any single device model over the others. Indeed, each device has some peculiarities that makes it more useful in specific settings. Current limitations in thoracic stent-grafts will hopefully be addressed with new designs of highly-individualized low-profile devices in order to extend the applicability of stent-graft technology in the thoracic aorta. Despite progress in configuration and flexibility and the greater availability of different devices compared to a decade ago, shortcomings of specific endovascular grafts including collapse, migration, or dislodgment have not been fully resolved. Nowadays the selection of patients on the basis of favourable anatomy and pathology is the key for the success of the procedure. Not all patients have lesions amenable to stent-graft repair (contraindications for endovascular treatment of thoracic aorta are still not marginal and mainly defined by anatomical constraints) and thoracic endografting is technically challenging, requiring dedicated facilities and experienced specialists. This paper discusses the different configurations and models of stent-graft for thoracic aortic disease as well as the still existing shortcomings.

Activity of a novel, dual PI3-kinase/mTor inhibitor NVP-BEZ235 against primary human pancreatic cancers grown as orthotopic xenografts

The phosphatidylinositol-3-kinase (PI3K)/Akt signalling pathway is frequently deregulated in pancreatic cancers, and is believed to be an important determinant of their biological aggression and drug resistance. NVP-BEZ235 is a novel, dual class I PI3K/mammalian target of rapamycin (mTor) inhibitor undergoing phase I human clinical trials. To simulate clinical testing, the effects of NVP-BEZ235 were studied in five early passage primary pancreatic cancer xenografts, grown orthotopically. These tumours showed activated PKB/Akt, and increased levels of at least one of the receptor tyrosine kinases that are commonly activated in pancreatic cancers. Pharmacodynamic effects were measured following acute single doses, and anticancer effects were determined in separate groups following chronic drug exposure. Acute oral dosing with NVP-BEZ235 strongly suppressed the phosphorylation of PKB/Akt, followed by recovery over 24 h. There was also inhibition of Ser235/236 S6 ribosomal protein and Thr37/46 4E-BP1, consistent with the effects of NVP-BEZ235 as a dual PI3K/mTor inhibitor. Chronic dosing with 45 mg kg⁻¹ of NVP-BEZ235 was well tolerated, and produced significant tumour growth inhibition in three models. These results predict that agents targeting the PI3K/Akt/mTor pathway might have anticancer activity in pancreatic cancer patients, and support the testing of combination studies involving chemotherapy or other molecular targeted agents.

The pathogenesis of Salmonella enteritidis in experimentally infected ducks: a quantitative time-course study using taqman polymerase chain reaction

Ducks were subcutaneously infected with a high-virulence strain of Salmonella enterica ssp. enterica serovar Enteritidis (Salmonella Enteritidis). The kinetics of the Salmonella Enteritidis genomic DNA loads, the immunohistochemical localization of the bacterial antigens, and the histopathological examination in various tissues were investigated. The results showed that the time course of the appearance of the Salmonella Enteritidis bacterial antigens and the lesions in various tissues was coincident with the bacterial load of the organism in various infected tissues. This suggests that Salmonella Enteritidis loads in systemic organs are closely correlated with the progression of the infection.

Characterization of a Staphylococcus Aureus Strain Showing High Levels of Biofilm Formation Isolated from a Vascular Graft: Case Report

A methicillin-susceptible Staphylococcus aureus strain, SA-DZ1, was isolated from an infected bypass crossover graft. Its general microbiological features were reminiscent of those previously described for the wound Wiley strain. Removal of the prosthetic device was necessary to resolve the infection. SA-DZ1 grown under different conditions showed a very strong and distinctive biofilm-producing phenotype, which was also visualized by confocal laser scanning microscopy. The biofilm extracellular matrix was essentially polysaccharidic, as determined by differential growth and physicochemical tests. By Multi Locus Sequence Typing (MLST), SA-DZ1 was classified as st94, a single locus variant of st8. Several other genetic traits assayed by PCR, such as agr-type and the presence of gene encoding proteins involved in adhesion and virulence (e.g. ica operon), confirmed the identifying features of this clinical isolate.

Outcome after endografting in small and large abdominal aortic aneurysms: a metanalysis

AIM

To compare the results of endovascular repair (EVAR) in large and small (diameter < 5.5cm) abdominal aortic aneurysms (AAA).

METHODS

A systematic review was performed to identify studies comparing the outcomes after EVAR of large and small aneurysms. Outcomes considered were: risk of death (perioperative, all cause, aneurysm-related), ruptures, and complications (conversion, reintervention). Weighted pooled estimates of outcomes in patients with small versus large aneurysms were calculated. The inverse variance method was used (random-effect model). Subgroup analyses by a follow-up longer or shorter than 24 months were performed.

RESULTS

Five studies, with published and unpublished data, totallying 7,735 patients, were included. Overall, the weighted pooled estimates were: OR 0.68; 95% CI 0.51-0.90 for operative mortality, OR 0.77; 95% CI 0.69 to 0.86 for all cause mortality, OR 0.58; 95% CI 0.40 to 0.87 for aneurysm-related mortality and OR 0.61; 95% CI 0.47 to 0.79 for rupture in favour of small AAA group. Pooled estimates were not influenced by follow-up length. Conversion and reintervention rates were not significantly lower for small AAA.

CONCLUSIONS

EVAR in small versus large AAA might be associated with lower operative mortality, aneurysm-related mortality and aneurysm rupture. Better evidence is needed to support these suggestions.

Acute limb ischemia in elderly patients: can iloprost be useful as an adjuvant to surgery? Results from the ILAILL study

OBJECTIVES

To evaluate the effects of iloprost, in addition to surgery, on the outcome of acute lower limb ischemia (ALLI).

DESIGN

Post-hoc analysis of a randomized, double-blind, placebo-controlled study.

METHODS

In the context of the ILAILL (ILoprost in Acute Ischemia of Lower Limbs) study, 192 elderly patients (>70 years old) undergoing surgery for ALLI were assigned to receive perioperative iloprost (intra-arterial, intra-operative bolus of 3000 ng, plus intravenous infusion of 0.5-2.0 ng/kg/min for six hours/day for 4-7 days following surgery), or placebo (iloprost: n=100; placebo: n=92). Patients were followed-up for three-months following surgical revascularization.

RESULTS

The combined incidence of death and amputation (primary study end-point) was significantly reduced in patients treated with iloprost (16.0% vs 27.2% in the placebo group; hazard ratio 1.99, 95% confidence interval 1.05-3.75, p=0.03). A statistically significant lower mortality (6.0%) was reported in patients receiving iloprost, compared to controls (15.2%) (hazard ratio 2.93, 1.11-7.71, p=0.03). The overall incidence of death and major cardiovascular events was lower in patients receiving iloprost compared to those assigned placebo (24.0% and 35.9%, respectively), at the limits of statistical significance (relative risk 1.64, 0.97-2.79, p=0.06).

CONCLUSIONS

These results confirm the poor outcome in elderly patients with ALLI. Based on a subgroup analysis iloprost, as an adjuvant to surgery, appears to reduce the combined end-point of death and amputation.

Timing of complications during carotid artery stenting. How can they be predicted?

Carotid artery stenting (CAS) is becoming increasingly common for the treatment of carotid stenosis. Accumulating data, but not randomised data, suggest that CAS has promising efficacy in preventing stroke with an acceptable rate of procedure-related complications when compared to carotid endarterectomy (CEA). However, CAS procedures can carry a risk of non-negligible complications such as cerebral embolization, cerebral hemorrhage, severe hypotension and bradycardia. These may occur after the first 24 hours. Lessons may be learned from the timing of occurrence of CAS adverse events. The most severe neurological complications are generally due to embolism and occur intraprocedurally especially during catheter, wire or sheath manipulation in the aortic arch and common carotid. These strokes, obviously, cannot be prevented by using cerebral protection devices and enhance the importance of an appropriate learning curve that includes proper material choice, patient selection, good technique and the skill of "know when to quit".

Conversion to Open Repair After Endografting for Abdominal Aortic Aneurysm: Causes, Incidence and Results

OBJECTIVE

To evaluate frequency, causes and results of conversion to Open repair (OR) after endovascular repair (EVAR) in a single centre during an 8-year period.

DESIGN

Six hundred and forty-nine consecutive patients undergoing EVAR were followed up prospectively for endograft-related complications.

OUTCOMES

Early conversion was any OR during or within 30 days from the primary EVAR. Late conversion was any OR with removal of the endograft after 30 days since a completed EVAR procedure.

RESULTS

Median patient follow-up was 38 months (1-93 months). Conversion to OR was performed in 38 patients; nine early and 29 late. Most (7/9) early conversions were due to extensive vessel calcification. Peri-operative mortality was 22% (2/9). Late conversions occurred at a median of 33 months after primary EVAR: 29 were elective and 4 urgent. During the same interval, 79 secondary endovascular interventions were performed, 7 of which failed. The risk of conversion to OR was 9% at 6 years. At multivariate logistic regression analysis, no single factor (short, large or angulated neck, suprarenal fixation, large pre-operative diameter, iliac aneurysms, ASA score risk) was associated with the risk of late failure requiring conversion to OR.

CONCLUSION

The risk of death after early conversion should be recognized, to avoid forcing morphological indications for primary EVAR. Occurrence of late conversion after EVAR is not negligible, affecting almost 1 out of 10 patients after 6 years. In the presence of an expanding aneurysm after EVAR, especially after a failed secondary endovascular correction, an aggressive attitude in fit patients allows outcomes at similar to those of primary OR.

A modified method of activity-based costing for objectively reducing cost drivers in hospitals

OBJECTIVES

Activity-based costing (ABC) is widely used to precisely allocate indirect costs to medical services. In the ABC method, the indirect cost is divided among the medical services in proportion to the volume of "cost drivers", for example, labor hours and the number of hours of surgery. However, the workload of data collection of cost drivers can be time-consuming and a considerable burden if there are many cost drivers. The authors aim to develop a method for objectively reducing the cost drivers used in the ABC method.

METHODS

In the ABC method, the cost driver is assigned for each activity. We assume that these activities and cost drivers are the best combination. Our method, that is cost driver reduction (CDR), can objectively select surrogates of the cost drivers for each activity in ABC from candidate cost drivers. Concretely, the total indirect cost of an activity is temporarily allocated to the medical services using each candidate of cost drivers. The difference between the costs calculated by each candidate and the proper cost driver used in ABC is calculated to evaluate the similarity by the evaluation function.

RESULTS

We estimated the cost of laboratory tests using our method and revealed that the number of cost drivers could be reduced from seven in the ABC to four. Similarly, the results of cost estimation obtained by our method were as accurate as those calculated using the ABC.

CONCLUSIONS

Our method provides two advantages compared to the ABC method: 1) it provides results that are as accurate as those of the ABC method, and 2) it is simpler to perform complicated estimation of hospital costs.

Comparison of surveillance vs Aortic Endografting for Small Aneurysm Repair (CAESAR) trial: study design and progress

OBJECTIVE

The CAESAR Trial aims to assess the outcome of endovascular repair (EVAR) vs surveillance of small abdominal aortic aneurysms (AAA) with maximum diameter of 4.1-5.4 cm on computerised tomography (CT) scan.

DESIGN

Patients between 50 and 80 years of age, with small AAA, anatomically suitable for EVAR, are randomly allocated to early EVAR or surveillance. The primary outcome measure is survival. Secondary endpoints include: aneurysm-related deaths (defined as any death caused directly or indirectly by rupture or endovascular/open aneurysm repair), AAA rupture, peri-operative or late complications, conversion to open repair, complications associated with delayed treatment including loss of treatment options, AAA growth rates and quality of life. Target recruitment is 740 patients to show that early EVAR is associated with a 15% survival benefit at 54 months.

PROGRESS

Randomization started in September 2004. By the end of April 2005, 86 patients had been enrolled by 10 active European centres. Completion of recruitment is expected for September 2006 and publication of the results in mid 2007.

Does gender influence outcome of AAA endoluminal repair?

BACKGROUND

It has been suggested that female patients have a less favourable outcome of endoluminal repair of abdominal aortic aneurysms. Yet, data on stratified per gender are lacking.

METHODS

We reviewed our prospective database of 402 endografts over a 4-year period and the peri- and postoperative course in the 25 (6%) female patients was compared with the 377 (94%) male patients. Median follow-up was 24 months (range 1-56 months). Logistic regression analysis was performed to test the effect of five confounding variables (gender, age, ASA grade IV, EUROSTAR class D or E, AAA diameter) on failure of AAA exclusion.

RESULTS

There were no perioperative deaths in the female group and 5 (1.3%) in the male group (p = 0.8). Major perioperative morbidity occurred in 17% versus 6% (OR 3.7; 95% CI 1.2-10.6; p = 0.026). There were 1 (4%) and 5 (1%) conversions to open repair in the female and male groups, respectively (p = 0.3). Late failure of AAA exclusion occurred in 5 (21%) and 26 (7%) patients, respectively (p = 0.03). Of the five variables examined for their influence on failure of AAA exclusion, female gender (hazard ratio 4.42; 95% CI 1.4-13.4; p = 0.009) and AAA diameter (hazard ratio 1.05; 95% CI 1.009-1.09; p = 0.017), were positive independent predictors of late failure of AAA exclusion on multivariate analysis.

CONCLUSION

Endoluminal AAA repair in female patients appear associated with a less favorable outcome when compared to their male counterparts. These data may be taken into consideration when endoluminal AAA repair is suggested to a female patient.

[Study of calcitonin gene methylation in chronic myeloid leukemia by using Hpa II-PCR]

To investigate the role of calcitonin(CT) gene hypermethylation in the transformation from the initial chronic phase to blast crisis of chronic myeloid leukemia, 31 CML patients were studied by using Hpa II-PCR. The results showed that the 10.52%(2/19) chronic phase, 71.4%(5/7) accelerated phase and 80.0%(4/5) blast crisis of patients had CT gene hypermethylation and that the increased methylation of the CT gene were related with the disease progression. The reports indicated that the hypermethylation of CT gene might be a useful marker for predicting the evolution of CML and selecting chronic phase patients for BMT.

Does the presence of an iliac aneurysm affect outcome of endoluminal AAA repair? An analysis of 336 cases

OBJECTIVE

To determine whether the presence of an iliac aneurysm compromises outcome of endovascular exclusion of AAA and to ascertain the fate of the iliac aneurysmal sac.

PATIENTS AND METHODS

Between April 1997 and March 2001, data on 336 consecutive patients undergoing endovascular repair for AAA were entered in a prospective database. Suitability for endovascular repair was assessed by preoperative contrast-enhanced computed tomography. A maximum common iliac artery (CIA) diameter > or = 20 mm was defined as iliac aneurysm. Patients with and without iliac aneurysms were compared to early (immediate conversion or perioperative death) and late failure (increase in aneurysm diameter or persisting graft-related endoleak, or late AAA rupture or conversion).

RESULTS

Fifty-nine patients (18%) had iliac aneurysms, 19 were bilateral, for a total of 78 aneurysmal iliac arteries (median diameter 23 mm; range 20-50 mm). A distal seal was achieved by landing in 33 external iliac arteries, in 20 ectatic CIAs, and in 25 normal CIAs. Operating time differed significantly between patients with and without CIA aneurysms (153 +/- 71 vs 123 +/- 55 min, p = 0.0001), whereas no statistically significant differences were found with respect to early and late failure (2% vs 3%, p = 0.5 and 14% vs 8%, p = 0.11, respectively). There were no cases of buttock or colon necrosis. At a median follow-up of 14 months (range 0-46; i.q.r. 7-27 months) common iliac diameter decreased > or = 2 mm in 49 cases, remained stable in 25, and increased > or = 2 mm in 3.

CONCLUSION

The presence of iliac aneurysm rendered endoluminal AAA repair more complex but did not affect feasibility and long-term outcome of the procedure. In our experience internal iliac exclusion was never associated with significant morbidity. These data may be useful when considering endovascular repair in high-risk patients with challenging anatomy.

Eversion vs conventional carotid endarterectomy: a systematic review

OBJECTIVE

to determine whether eversion carotid endarterectomy (CEA) was safe and more effective than conventional CEA.

METHODS

controlled trials comparing eversion vs conventional technique for CEA were identified from the Cochrane Stroke Review Group database plus additional hand searching. Researchers were contacted to identify additional published and unpublished studies. Randomised and pseudorandomised trials comparing eversion to conventional techniques in patients undergoing CEA were examined. Outcomes included stroke and death, carotid restenosis/occlusion, and local complications.

RESULTS

five trials were included comprising 2465 patients and 2590 arteries. There were no significant differences in the rate of perioperative stroke or death (1.7% vs 2.6%, odds ratio [OR] 0.44, 95% confidence interval [CI] 0.10-1.82) and stroke during follow-up (1.4% vs 1.7%; OR: 0.84; 95% CI: 0.43-1.64) between eversion and conventional CEA techniques. Eversion CEA was associated with a significantly lower rate of restenosis >50% during follow-up (2.5% vs 5.2%, OR: 0.48, 95% CI: 0.32-0.72). There were no statistically significant differences in local complications between the eversion and conventional group. When eversion procedures were compared with patch procedures only, non-significant differences were found in primary outcomes.

CONCLUSIONS

eversion CEA may be associated with low risk of arterial occlusion and restenosis. However, numbers are too small to definitively assess the benefits and disadvantages of eversion CEA. Reduced restenosis rates did not appear to be associated with clinical benefit in terms of reduced stroke risk, either perioperatively or later. Until further evidence is available, the choice of the CEA technique should be based on the experience and familiarity of the individual surgeon.

A 12-amino-acid segment, present in type s2 but not type s1 Helicobacter pylori VacA proteins, abolishes cytotoxin activity and alters membrane channel formation

Helicobacter pylori, a gram-negative bacterium associated with gastritis, peptic ulceration, and gastric adenocarcinoma in humans, secretes a protein toxin, VacA, that causes vacuolar degeneration of epithelial cells. Several different families of H. pylori vacA alleles can be distinguished based on sequence diversity in the "middle" region (i.e., m1 and m2) and in the 5' end of the gene (i.e., s1 and s2). Type s2 VacA toxins contain a 12-amino-acid amino-terminal hydrophilic segment, which is absent from type s1 toxins. To examine the functional properties of VacA toxins containing this 12-amino-acid segment, we analyzed a wild-type s1/m1 VacA and a chimeric s2/m1 VacA protein. Purified s1/m1 VacA from H. pylori strain 60190 induced vacuolation in HeLa and Vero cells, whereas the chimeric s2/m1 toxin (in which the s1 sequence of VacA from strain 60190 was replaced with the s2 sequence from strain Tx30a) lacked detectable cytotoxic activity. Type s1/m1 VacA from strain 60190 formed membrane channels in a planar lipid bilayer assay at a significantly higher rate than did s2/m1 VacA. However, membrane channels formed by type s1 VacA and type s2 VacA proteins exhibited similar anion selectivities (permeability ratio, P(Cl)/P(Na) = 5). When an equimolar mixture of the chimeric s2/m1 toxin and the wild-type s1/m1 toxin was added to HeLa cells, the chimeric toxin completely inhibited the activity of the s1/m1 toxin. Thus, the s2/m1 toxin exhibited a dominant-negative phenotype similar to that of a previously described mutant toxin, VacA-(Delta6-27). Immunoprecipitation experiments indicated that both s2/m1 VacA and VacA-(Delta6-27) could physically interact with a c-myc epitope-tagged s1/m1 VacA, which suggests that the dominant-negative phenotype results from the formation of heterooligomeric VacA complexes with defective functional activity. Despite detectable differences in the channel-forming activities and cytotoxic properties of type s1 and type s2 VacA proteins, the conservation of type s2 sequences in many H. pylori isolates suggests that type s2 VacA proteins retain an important biological activity.

[The language healing system of deaf children based on wavelet transform]

In the language healing system of deaf children, the wavelet transform method is employed to describe the time-varying characteristics of speech signals, improve the resolution of speech spectrum and make the speech characteristics more obvious. The speech spectrum information shown in this system is easier for deaf children to observe and understand and it is of great importance to the language healing of deaf children.

Parameters influencing membrane CD14 expression and soluble CD14 levels in sepsis

INTRODUCTION

Membrane (mCD14) and soluble (sCD14) CD14 are pattern recognition receptors for bacterial cell wall fragments. They play an important role in the generation of the innate immune response against bacterial pathogens. Differential expression of these receptors may be relevant for the clinical course of patients with sepsis.

PATIENTS AND METHODS

32 patients with an early onset of sepsis (duration of symptoms < 24h) were examined repeatedly by flow cytometry for expression of mCD14, and by ELISA for levels of sCD14, leukocyte elastase and C-reactive Protein (CRP).

RESULTS

At study entry, mCD14 expression was reduced in all patients with sepsis, but returned to normal levels during the course of the disease in survivors only. mCD14 was found to be inversely correlated with severity of disease, leukocyte elastase, and C-reactive protein. Among patients with severe disease and Apache II scores >or= 20, sCD14 levels at study entry were significantly higher in those who survived by day 28, as compared to non-survivors (p = 0.02).

CONCLUSION

The data presented are compatible with a recently published hypothesis derived from in vitro experiments suggesting that leukocyte elastase may be responsible for cleavage of mCD14 from the monocyte surface. The data also suggest that higher sCD14 levels may be beneficial in sepsis. Persistently reduced mCD14 expression seems to be a marker for severity of disease in patients with sepsis.

Antigenic diversity among Helicobacter pylori vacuolating toxins

Helicobacter pylori vacuolating cytotoxin (VacA) is a secreted protein that induces vacuolation of epithelial cells. To study VacA structure and function, we immunized mice with purified type s1-m1 VacA from H. pylori strain 60190 and generated a panel of 10 immunoglobulin G1kappa anti-VacA monoclonal antibodies. All of the antibodies reacted with purified native VacA but not with denatured VacA, suggesting that these antibodies react with conformational epitopes. Seven of the antibodies reacted with both native and acid-treated VacA, which suggests that epitopes present on both oligomeric and monomeric forms of the toxin were recognized. Two monoclonal antibodies, both reactive with epitopes formed by amino acids in the carboxy-terminal portion of VacA (amino acids 685 to 821), neutralized the cytotoxic activity of type s1-m1 VacA when toxin and antibody were mixed prior to cell contact but failed to neutralize the cytotoxic activity of type s1-m2 VacA. Only 3 of the 10 antibodies consistently recognized type s1-m1 VacA toxins from multiple H. pylori strains, and none of the antibodies recognized type s2-m2 VacA toxins. These results indicate that there is considerable antigenic diversity among VacA toxins produced by different H. pylori strains.

[New progress of surface enhanced Raman spectroscopic studies on a gold electrode in a nonaqueous system]

Based on a highly sensitive new generation confocal microprobe Raman system, the adsorption behavior of thiocyanate (SCN-) on a gold electrode in methanol solution was investigated by SERS for the first time. Preliminary results demonstrated that the interaction between SCN- and the electrode is so strong that its SERS signal can be detected in the whole research potential region (-0.1 V(-)-1.4 V). The orientation change may occur in the potential range -0.6 V-0.7 V. From -0.1 V to -0.6 V SCN- is adsorbed mainly through S end onto Au surface while in the potential range of -0.7 V to -1.2 V it is oriented mainly through N end. The potential dependence of the Raman frequency of nu CN resulted in two different values of electrochemical Stark effect, suggesting the existence of molecular orientation change.

[The quantitative analysis of voice disease based on fractal method]

The fractal method is employed to check the voice diseases. The severity of pathological changes of human voice can be analyzed objectively and quantitatively with different fractal dimensions. With this method we can end up the history of judging the voice with subjective hearing and it is of great importance to the development of laryngology.

Endovascular Abdominal Aortic Aneurysm Repair in High-risk Patients: a Single Centre Experience

OBJECTIVES

to evaluate the role of endovascular repair (ER) of abdominal aortic aneurysm (AAA) repair in American Society for Anaesthesiology [ASA] class IV patients.

PATIENTS AND METHODS

between April 1997 and March 2000, 266 consecutive patients underwent ER for AAA. There were 26 patients (10%) with ASA grade IV. The remaining 240 patients, ASA grade between I and III (ASA<IV group), were compared with the ASA IV group. Mean follow-up was 11.6 months (range 1-32 months). Increase in AAA diameter after ER or persisting graft-related endoleak were defined as failure of AAA exclusion. Regression analysis was performed to test the effect of five confounding variables on failure of AAA exclusion and perioperative mortality.

RESULTS

patients in the ASA IV group were significantly older than patients in ASA <IV group (mean age: 74 years vs 70 years p=0.005). AAA were larger (mean diameter: 56 mm vs 50 mm p =0.002) and more extensive (class E of EUROSTAR classification: 27% vs 5.8% p =0.002). There were two perioperative deaths in the ASA IV group and one in the ASA<IV group (8% vs 0.4%; RR 19; 95% CI 1.8-202 p=0.01). Major perioperative morbidity occurred in 8% of patients in the ASA IV group and in 3.3% in the ASA<IV group (n.s.). There were no conversions to open repair in the ASA IV group while six were performed in the ASA<IV group (n.s.). Length of hospitalisation was significantly longer for patients in the ASA IV group: 7.8 days vs 3.2 days (p =0.001). Operative times and blood loss were similar. Failure of AAA exclusion occurred in two patients (8%) in the ASA IV group and in four patients (1.6%) in the ASA<IV group (n.s.). On life table analysis, survival rates at 26 months were 76% in the ASA IV group and 89% in the ASA<IV group (p =0.004). Five variables were examined by regression analysis and no independent predictors of failure of AAA exclusion and operative mortality were found.

CONCLUSIONS

ER in ASA IV patients is feasible and effective with acceptable actuarial survival rates. However, the endovascular procedure in these patients is associated with higher major systemic morbidity, mortality, and prolonged hospitalisation rates.

Visual responses of neurons in the pretectal nucleus lentiformis mesencephali to moving patterns within and beyond receptive fields in pigeons

Large-field patterns are effective stimuli for eliciting visual responses from neurons in the pretectal nucleus lentiformis mesencephali of nonmammals. The present study shows that stimulation beyond the receptive field does not contribute to the visual responses of neurons in the nucleus lentiformis mesencephali in two respects. First, changes in the direction and velocity of motion beyond the receptive field did not affect the visual responses of the pretectal cells to motion within the receptive field. Second, time differences in the onset of stimulation within and outside the receptive field did not influence the visual responses of the pretectal cells to motion in the receptive field, implying that there may be no long-range interaction between the receptive field and its surrounding field. The present study also indicates that the pretectal cells are not only sensitive to the direction and velocity of motion, but also to the size and density of dots in a random-dot pattern moving through the receptive field. Taken together with previous studies, these results suggest that the receptive field of the pretectal cells within the nucleus lentiformis mesencephali is large in size but well defined in boundaries, and that the pretectal cells respond to motion of visual stimuli within but not beyond their receptive fields.

Amino-terminal hydrophobic region of Helicobacter pylori vacuolating cytotoxin (VacA) mediates transmembrane protein dimerization

Helicobacter pylori VacA is a secreted protein toxin that forms channels in lipid bilayers and induces multiple structural and functional alterations in eukaryotic cells. A unique hydrophobic segment at the amino terminus of VacA contains three tandem repeats of a GxxxG motif that is characteristic of transmembrane dimerization sequences. To examine functional properties of this region, we expressed and analyzed ToxR-VacA-maltose binding protein fusions using the TOXCAT system, which was recently developed by W. P. Russ and D. M. Engelman (Proc. Natl. Acad. Sci. USA 96:863-868, 1999) to study transmembrane helix-helix associations in a natural membrane environment. A wild-type VacA hydrophobic region mediated insertion of the fusion protein into the inner membrane of Escherichia coli and mediated protein dimerization. A fusion protein containing a mutant VacA hydrophobic region (in which glycine 14 of VacA was replaced by alanine) also inserted into the inner membrane but dimerized significantly less efficiently than the fusion protein containing the wild-type VacA sequence. Based on these results, we speculate that the wild-type VacA amino-terminal hydrophobic region contributes to oligomerization of the toxin within membranes of eukaryotic cells.

[The relationship between clinical prognosis and classification of the isoforms of fuse gene in acute promyelocytic leukemia]

To check the anti-apoptosis gene bcl-2 protein/mRNA expression in 28 acute promyelocytic leukemia (APL), by immunohistochemistry and in situ hybridization, and to analyse the relationship among the bcl-2 gene expressions, clinical prognosis and classification of the isoforms of fuse gene in APL. The result shows the two types of isoforms of PML-RAR alpha have no significance in bcl-2 protein/mRNA expression, indexes of clinical prognosis. This shows that the classification of PML-RAR alpha isoform has no influence on clinical prognosis.

[Analysis of impulse response of rectangular ultrasound transducer]

A new expression for calculating the impulse response of rectangular pistonlike transducers, proper to any points of acoustic field, is presented. The radiated field of ultrasound transducer can be analyzed using impulse response method, avoiding paraxial and farfield approximation. The velocity potential at an observation point is expressed as the convolution of the excitation velocity and the impulse response. A time-amplitude shift method for the far field impulse response of small aperture transducers is presented. The radiated field of rectangular transducers is calculated through the new method and the previous method and excellent agreement is observed.

[Two-dimensional surface Raman imaging of a roughened iron electrode in saline solution]

By using a confocal microprobe Raman system and proper surface roughening procedure for iron, the pit corrosion behavior of bare iron electrode in 3.4% NaCl (saline solution) solution has been investigated. The surface-enhanced Raman scattering (SERS) spectra of the corrosion products due to the pit corrosion at positive potential was obtained with high ratio of signal to noise. The application of SERS technique has been extended successfully to the study of iron corrosion. The two-dimensional surface Raman imaging acquired at 660 cm-1 was obtained also with the utility of surface Raman image technique. Results show that different iron oxides should coexist in the pit corrosion region and the distribution of the corrosion products was not uniform.