The revival of nitric acid for the treatment of anogenital warts.

The destruction of small lesions by tissue denaturation (fixation) rather than erosion (acid hydrolysis) is accomplished by nitric acid of moderate strength in which nitric acid reduction products are generated by nitric acid oxidation of added organic acids. Such solutions show a temperature-dependent increase or loss of nitrite during storage, with loss of therapeutic activity when nitrite levels decrease after storage at cooler temperatures. Use of a preparation technique that completely consumes all the oxidizable organic components added to generate nitrite results in a stable preparation that is effective, well tolerated, and convenient in the treatment of anogenital warts (condylomata acuminata). Of 50 patients monitored after treatment with a 6.6 mol/L nitric acid preparation with no residual oxidizable organic agents, results were good in 39 patients, satisfactory in four patients, and unsatisfactory in seven patients. These observations lead to a simplified stable preparation of modest nitric acid concentration with adequate nitrate reduction products for efficacy in the topical ablation of small skin lesions such as condylomata acuminata.

Application of a vascular graft material (Solcograft-P) in experimental surgery.

The implantation and post-implantation behaviour of a Solcograft-P vascular prosthesis in the aortic, aorto-iliac, carotid and vena caval positions in dogs was studied up to 100 d post-surgery in order to assess the suitability of this vascular material for use in man. Solcograft-P is prepared from the carotid arteries of calves by crosslinking the collagen stroma using adipyl dichloride. During the postoperative follow-up period of 3 month, 100% of the aortal grafts, 80% of the aorto-iliac bypasses, 60% of the vena caval grafts and 35% of the carotid implants remained patent. The biochemical properties of the Solcograft-P are better than those of Solcograft, its predecessor. The intimal lining was consistently smooth and homogeneous in grafts of biological origin, and no aneurysm was observed. Infection and early thrombosis occured no more frequently than with other grafts. The new Solcograft-P, crosslinked via ester and amide groups, seems to represent a real improvement over Solcograft. Our results suggest that Solcograft-P should prove valuable in various cases of reconstructive vascular surgery of the lower limb, especially when the autologous vena saphena magna is not available, and its mechanical properties may well prove suitable for both arterial and venous replacement.

Acceptance of flexible sigmoidoscopy as a screening examination for colorectal cancer in an outpatient clinic.

BACKGROUND AND STUDY AIM: Flexible sigmoidoscopy (FS) is a feasible examination technique and a suitable tool for population-based screening, but very little is known about determinants of endoscopic screening participation. The aim of this study was to determine the acceptance rate and the factors influencing the decision of participating in a screening program for patients in an outpatient clinic. MATERIALS AND METHODS: In this prospective study, a colorectal cancer screening by FS was offered to 631 patients older than 40 years. Three strategies were available, (1) to have the endoscopy on the same day, (2) to make an appointment for another day, or (3) to take time to think about if they wanted the procedure. The reasons for refusal of the FS were documented. RESULTS: 419 of the 631 (66.4%) patients had no interest to take part in the screening program during their outpatient visit. Two hundred twelve (33.6%) patients were primarily interested on FS, but only 110 of them were finally examined. In total, 102 patients did not make an appointment for FS or did not appear for the endoscopy. The participation rate was therefore 17.4% (110/631) of all patients. Of the patients who agreed to receive an on-site examination, 78.3% were examined compared to 18.8% of patients who fixed the appointment for another day or after taking time to reflect upon the FS procedure. More male than female patients accepted the FS screening. Recommended colonoscopy was finally performed in 76%. Thirty-three polyps were found during the screening program of which 18 were larger than 0.5 cm. No CRC was detected. All patients agreed to repeat the FS every 5 years. CONCLUSIONS: This study demonstrates that a screening examination will be most likely performed if it is done as an on-site examination. In contrast, the participation rate is low if the patient has to make an appointment by himself. Acceptance of FS screening is also dependent on the patient's gender and family history of cancer. Additional strategies are needed to further improve participation.

Diameter of coronary arteries in 36 species of mammalian from mouse to giraffe.

Systematic quantitative investigations were performed in the coronary arteries of 102 hearts of 36 mammal species with an overall more than tenthousandfold difference of their heart weight. After postmortem coronary angiography with a filling pressure of 100 mm Hg x-rays were taken, and the widest diameters of the coronary artery stems were determined. We found a nearly linear correlation between diameter of a standardized coronary artery and virtual diameter of heart, but the increase in diameter of coronary arteries exceeded somewhat that of the diameter of heart especially for heart weights surmounting 100 g. Perhaps relative enlargement of coronary arteries in the bigger hearts contributes to the prevention of large increase of blood flow velocity.

[Vascular replacement of small caliber arteries--a new bovine collagen prosthesis]. / Gefässersatz bei kleinkalibrigen Arterien--eine neue bovine Kollagenprothese.

A new bovine collagenic prosthesis (Solcograft P) was tested in animal experiments. In 45 dogs the infrarenal abdominal aorta was substituted. During a follow-up period of up to 18 months the functional rate amounted to 88%. Joint-crossing iliaco-femoral bypasses were implanted in 31 dogs, 5 times in both sides. For the new bovine collagenic graft the functional rate ran up to 83%, during a follow-up period of 9 months. A wound infection was observed twice in the inguinal region thus exacting the removal of the prosthesis. An aneurysm was not observed. In our opinion the satisfying results are due to the compliance of the new prosthesis which is similar to natural artery.

Morphological experiences with a new bovine carotis xenograft (Solcograft-P) in experimental vascular surgery.

The implantation process of the Solcograft-P vascular prosthesis in infrarenal aortic and vena cava inferior positions was studied in dogs in the first 100 postoperative days to investigate its applicability in vascular surgery. The intimal lining was consistently smooth and homogeneous, the problems of aneurysma formation was not serious. Infection and early thrombosis were not more frequent than with other grafts. The impregnated Solcograft-P seemed to be superior to its previous version, the Solcograft. The morphological properties of Solcograft-P seem to make it suitable for venous replacement. The experiments suggested that in selected cases of reconstructive vascular surgery and particularly for patch plastics, Solcograft-P may prove useful.

[Comparative experimental studies with biologic materials for replacement of the anterior cruciate ligament]. / Vergleichende experimentelle Untersuchungen an biologischen Materialien zum Ersatz des vorderen Kreuzbandes.

Allogeneic and xenogeneic biological tendon and ligament materials for ligament replacement were tested in the knee of rabbits and sheep. In-vitro and ex-vivo biomechanical tests as well as micromorphological investigations following implantation were performed. The preparation procedure mainly consists in cross linking of collagen by dicarboxylic acids (DC). Modifications in the method induce changes in the biomechanical stability also after implantation. Sheep with autologous patellar tendons substitutions and glutaraldehyde (GA) fixed bovine tendons served as controls. Because of biocompatibility reasons the later seem to be not yet suitable for clinical applications. The DC-tendons need for improved midterm stability prior to clinical implantations; the biocompatibility appears to be excellent.

Experimental bioprosthetic reconstruction of the trachea.

We removed the tracheas from sacrificed laboratory animals and subjected this tissue to multi-step chemical processing. This method allowed us to preserve the cartilage and reduce its antigenicity, thus creating a bioprosthesis very similar to the host tissue. By using allogeneic and xenogeneic prostheses so prepared, no signs of immune rejections were seen following heterotopic or orthotopic implantations. The transplanted cartilage remained stable for periods ranging up to 21 weeks in recipient rats, while partial morphologic integrity of the cartilage was seen up to 1 year in pigs. Reepithelialization of the transplant with ciliated epithelium was completed in all specimens 12-24 weeks following surgery. Segmental replacement of up to one third of the whole trachea was possible in rats, whereas similar segmental replacements failed in pigs. We also found that successful reconstruction of window-shaped defects was possible. We consider our tracheal bioprosthesis to be superior to cialit-preserved grafts and also to most other biological reconstruction procedures.