The role of Chlamydia pneumoniae in human aortic disease-a hypothesis revisited.

BACKGROUND: The role of Chlamydia pneumoniae in the pathogenesis of aortic aneurysm is controversial. We investigated the presence of C. pneumoniae in tissue samples excised from patients and controls. METHODS: Aortic wall specimens were obtained from 17 patients with acute Stanford type A aortic dissection, 25 patients with thoracic aortic aneurysms (TAA) and 23 patients with abdominal aortic aneurysms (AAA). Eighty-three tissue samples of 73 control patients free of aortic disease were obtained either at surgery or autopsy. The presence of Chlamydia subspecies DNA (sequences specific for all known Chlamydiaceae) and DNA of C. pneumoniae, C. trachomatis and C. psittaci were assessed by a validated highly sensitive and specific real time polymerase chain reaction (PCR) analysis. Atherosclerotic risk factors were assessed in all patients. RESULTS: We failed to detect C. pneumoniae and C. psittaci-DNA in any of the 148 vessel specimens. C. trachomatis-DNA was detected in 1/65 patients and in none of 83 controls (P=0.43). Chlamydia subspecies DNA was found in samples of eight cases and in one control (P=0.01), however, no significant differences were found between the subgroups aortic dissection (P=0.09), TAA (P=0.99) and AAA (P=0.15) and respective controls. CONCLUSIONS: C. pneumoniae does not play a clinically relevant role in acute and chronic aortic disease. The impact of other organisms of the family Chlamydiaceae needs further evaluation.

Compact, broad-bandwidth fiber laser for sub-2-microm axial resolution optical coherence tomography in the 1300-nm wavelength region.

A novel, compact, user friendly fiber laser with a broad emission bandwidth (MenloSystems, lambdac = 1375 nm, deltalambda = 470 nm, Pout = 4 mW) was used to achieve unprecedented sub-2-microm axial resolution optical coherence tomography (OCT) in nontransparent biological tissue in the 1300-nm wavelength region. Fresh human skin and arterial biopsies were imaged ex vivo with approximately 1.4-microm axial and approximately 3-microm lateral resolution and 95-dB sensitivity, demonstrating the great potential for clinical OCT applications of this stable, low-cost, and turn-on-key fiber laser.

Endovascular repair of thoracic aortic aneurysms.

The standard technique for the treatment of descending thoracic aortic aneurysms is elective open surgical repair with graft interposition. This standard approach, although steadily improving, is associated with high morbidity and substantial mortality rates and implies a major surgical procedure with lateral thoracotomy, use of cardiopulmonary bypass, long operation times and a variety of peri- and postoperative complications. This and the success of the first endoluminal treatment of abdominal aortic aneurysms by Parodi et al. prompted the attention to be thrown on the treatment of descending thoracic aortic aneurysms with endoluminal stent-grafts in many large centres. The aim of this new minimally invasive technique is to exclude the aneurysm from blood flow and in consequence to avoid pressure stress on the aneurysmatic aortic wall, by avoiding a large open operation with significant perioperative morbidity. The potentially beneficial effect of this new treatment approach was evaluated in the course of this study.

Reasons for 50% reduction in the number of organ donors within 2 years--opinion poll amongst all ICUs of a transplant centre.

To detect the reasons for a massive decrease in the annual number of organ donors and as a means of evaluating the effectiveness of our information programme, a questionnaire was designed and sent to all intensive care units (ICUs) in our catchment area. We wished to obtain information about medical, organizational and capacity problems and negative occurrences that had happend during past retrievals. Although 60% of the answers we reiceved (87% feedback rate) mentioned the additional workload involved in treating an organ donor (and 88% had serious problems because of the shortage of nurses), less than 16% remembered a "lost" donor because of capacity problems. Eighty-six percent recognized our efforts to support them in any respect and were satisfied with the amount of "service" provided by the transplantation (TX) centre. About 45% remembered negative occurrences. More than 85% of all replies asked for more and continuing information related to organ donation and transplantation. We think that the key to a successful TX programme is a system of active care for the ICU staff in all peripheral hospitals; repeated mailing of updated information brochures, annual lectures about new developments, letters of thanks after each reported donor (including information on the fate of the organs), visiting donor ICU's accompanied by successfully transplanted recipients, etc.... The downwards trend of donor rates in our area clearly shows that it takes more than a stable legal situation to ensure the necessary amount of donor organs, even a very successful TX centre has to work hard to maintain a certain standard of knowledge, information and motivation amongst the staff of the peripheral hospitals. Moreover, the high turnover rate of ICU personnel requires a steady "flow of information" and cooperation between the "transplant people" and their coworkers outside to guarantee a permanent state of awareness concerning organ donation and transplantation. In fact, awareness seems to be the key issue: the activity of sending out the questionnaires was enough to raise the number of reported donors from 72 (estimated in July) to 96 (31 December 1992).