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Biomedical subjects

C Jerusalem

Publications and source records attributed to C Jerusalem.

At least 19 recordsLinked to original sources
PubMed1993

Patency and morphology of fibrous polyurethane vascular prostheses implanted in the femoral artery of dogs after seeding with subcultivated endothelial cells.

A cell culture line was established from enzymatically-derived canine jugular endothelial cells and further cultured. Whenever sufficient cells were present, fibrous polyurethane vascular prostheses, impregnated with gelatin and coated with fibronectin, were seeded with 4.8 x 10(5)/cm2 cells, sufficient to establish a confluent monolayer, and implanted in the femoral arteries of 16 dogs. A non-seeded prosthesis on the contralateral side served as control. Eight dogs received antiplatelet aggregation medication: 250 mg aspirin together with 25 mg dipyridamole, orally three times daily, starting 2 weeks prior to the implantation operation and continued for the duration of the experiment. Results show that in the non-medicated dogs all control prostheses become occluded within 3 weeks after implantation, whereas five out of eight seeded prostheses remained patent. In the medicated group, two out of eight control prostheses occluded and all seeded prostheses remained patent. Scanning and light microscopy revealed that seeded prostheses were completely lined with endothelial cells (Factor VIII positive stain) week 3 (n = 3) and 12 (n = 3) after implantation, while endothelialisation in control prostheses had advanced only 5 mm into the prostheses in 12 weeks. Two dogs of each group were included in long-term patency studies. We conclude that prostheses seeded with a confluent monolayer of endothelial cells result in superior patency rates for both medicated and non-medicated dogs. No immunological reaction against the (allogeneic) seeded endothelial cells were noted.

Anastomosis, Surgical↗
PubMed1992

Seeding of enzymatically derived and subcultivated canine endothelial cells on fibrous polyurethane vascular prostheses.

Fibrous polyurethane (FPU) prostheses with or without fibronectin coating and gelatin impregnation and FPU prostheses with or without fibronectin coating were seeded with 4.8 x 10(5) subcultivated dog endothelial cells per cm2 prosthesis. Expanded polytetrafluoroethylene (ePTFE) prostheses with and without fibronectin coating served as controls. The numbers of cells retained on uncoated polyurethane prostheses were minimal but increased with fibronectin coating and/or gelatin impregnation. Adhering cells were predominantly round in shape and few cells were seen stretched over the prosthetic fibres. Optimum numbers of cells were found in prostheses impregnated with gelatin and coated with fibronectin, where almost all the cells were stretched forming a confluent monolayer. In ePTFE prostheses only minimal numbers of cells were retained but in the fibronectin-coated prostheses a high cell count was noted. Gelatin-impregnated and fibronectin-coated FPU prostheses, as well as ePTFE prostheses coated with fibronectin, were additionally perfused in vitro after seeding under nearly physiological conditions for 1 h. Cells in the FPU prostheses were still present after perfusion, whereas all the cells in the ePTFE prostheses were lost from the inner surface. It is concluded that FPU prostheses impregnated with gelatin and coated with fibronectin are a suitable substrate for subcultivated endothelial cells to be seeded on. The cells remained at the surface even after 1 h in vitro perfusion with tissue culture medium under nearly physiological conditions. Further research including in vivo implantations is indicated.

Animals↗
PubMed1991

Failure to obtain long-term patency after implantation of fibrous polyurethane prostheses in the carotid arteries of rabbits.

Fibrous polyurethane prostheses were implanted in the carotid arteries and aortae of New Zealand white (NZW) and Chinchilla (CHIN) rabbits. No immediate post-implantation patency was obtained after implantation in the carotid arteries in NZW rabbits. In CHIN rabbits patency up to 1 week was obtained after carotid implantation. Attempts to increase patency rates by administration of 20 mg/kg body weight/day of both dipyridamol (DIP) and acetyl-salicylic acid (ASA) p.o., starting the week before implantation, had an adverse effect; prostheses became occluded within a few hours after implantation. Coagulation tests (Lee and White, Am J Med Sci 145:495-503, 1913) carried out with blood drawn from CHIN rabbits revealed hypercoaguability after administration of either 10 or 20 mg/kg body weight/day of both DIP and ASA compared to pre-medication values. Prostheses implanted in the aortae of both strains remained patent without anti-platelet-aggregation therapy for a 3-month observation period. It is concluded that in the NZW rabbit carotid implantation was not successful due to severe spasmic reactions and that in CHIN rabbits only very short-term patency could be obtained both with and without administration of 10 or 20 mg/kg body weight/day medication DIP and ASA.

Animals↗
PubMed1990

Comparative study of lyophilized human dura mater and lyophilized bovine pericardium as dural substitutes in neurosurgery.

In a prospective, controlled randomized study either lyophilized bovine pericardium or lyophilized human dura mater have been used as a patch for the closure of the dura in 102 patients. The aim of this investigation was to compare both materials in terms of immunogenic response of the patients. The rate of post-operative complications was comparably low in both groups (wound infection in 1/51 patients each). In regard of workability, thickness of the material and flexibility the pericardium patches were judged to be by far superior. Neither signs of a cellular nor of an intesified humoral response could be detected in patients who received the pericardium implants. Thus, lyophilized bovine pericardium seems to be a superior alternative for the surgical repair of dural defects.

Animals↗
PubMed1989

Neointima formation in expanded polytetrafluoroethylene vascular grafts with different fibril lengths following implantation in the rat aorta.

Expanded polytetrafluoroethylene (PTFE) prostheses with fibril lengths of 30 and 60 microns were implanted in the rat infrarenal aorta. Sequential scanning electron and light microscopic studies of the prostheses after implantation demonstrated a different pattern of endothelialization. Prostheses with a fibril length of 60 microns had a continuous multilayered neointima at week 25 postimplantation, whereas prostheses with a 30-microns fibril length had a discontinuous and single layer of endothelium after the same interval. It was concluded, therefore, that a prerequisite for the development of a lining in a vascular prosthesis is for the inner surface of the prosthesis to have adequate pores for effective anchoring of the invading endothelioid cells. Expanded PTFE prostheses with an internodular distance of 60 microns provided sufficient anchoring possibilities for invading endothelioid cells to form a continuous neointima.

Actin Cytoskeleton↗
PubMed1989

Auxiliary liver transplantation in jaundiced rats with UDP-glucuronyltransferase deficiency and defective hepatobiliary transport.

In this study auxiliary liver transplantation (ALT) has been tested as a means of correcting the UDP-glucuronyltransferase deficiency in Gunn rats and the UDP-glucuronyltransferase deficiency and impaired hepatobiliary bilirubin transport in double mutant rats. In both groups serum bilirubin normalized and remained low until the end of the study at 12 weeks after transplantation in 4 out of 6 rats. Excretion of 99mTc-HIDA in non-transplanted double mutants was considerably slower than in Gunn rats (kel 0.9 x 10(-3) versus 4.3 x 10(-3) s-1). HIDA excretion by transplants in double mutants and Gunn rats was about equal (kel 1.6 x 10(-3) and 1.1 x 10(-3) s-1). Experiments with bile duct-cannulated transplants showed that in double mutants bile flow, bile acid and bilirubin excretion was 2-4 times higher than in Gunn rats. This study shows that auxiliary liver transplants can conjugate and excrete bilirubin when one of these or both functions are lacking in the recipient's liver.

Animals↗
PubMed1988

Patency rate of small caliber fibrous polyurethane vascular prostheses implanted in the dog carotid and femoral artery improved by use of acetylsalicylic acid and dipyridamol.

Segments of 3 mm diameter fibrous polyurethane vascular prosthesis of length 3-4 cm were prepared. They were bilaterally implanted in the carotid and femoral arteries of male and female beagles. Four groups consisting of animals receiving either no medication or thrombocyte aggregation drugs were studied: Group A (8 dogs), no medication: group B (19 dogs), 500 mg acetylsalicylic acid (ASA) once daily and 25 mg dipyridamol (DIP) three times daily orally for 6 weeks after the implantation operation; group C (14 dogs), 250 mg ASA and 25 mg DIP three times daily orally for 6 weeks after the implantation operation; group D (12 dogs), 250 mg ASA and 25 mg DIP three times daily orally for 25 weeks after the implantation operation. Medication was started one week prior to the implantation operation. In group A, all prostheses were occluded at week 6. There was a significant difference in patency rates between groups B-D and C-D. No significant differences in patency rates could be found between groups B and C. The best patency rates were obtained 25 weeks after implantation in group D for both the right and left carotid and right and left femoral implantation sites. Highest patency rates were observed when ASA and DIP were given for 25 weeks.

Animals↗
PubMed1988

Implantation of 20 cm long polyurethane vascular prostheses in the femoral artery of dogs. Preliminary results.

In a preliminary experiment externally reinforced polyurethane prostheses measuring 20 cm in length, with an inner diameter of 3 mm, were implanted in a loop in the femoral artery of six dogs. The dogs received 250 mg acetylsalicylic acid and 25 mg dipyridamol three times a day as anti-thrombocyte aggregation therapy starting three weeks prior to surgery. Anti-thrombocyte aggregation therapy was continued throughout the study. All prostheses remained patent 8, 9, 15 and 17 months after implantation. Patency was confirmed by palpation and Doppler ultrasound measurements. Preliminary results suggest that in clinically relevant situations, these prostheses could function well over prolonged periods of time.

Animals↗
PubMed1987

Determination of the patency of vascular prostheses implanted in the rat aorta by means of ultrasonic blood-flow measurements.

Patency of vascular prostheses implanted in the rat aorta is usually confirmed by reoperation and inspection of the distal stump of the aorta for pulsations. Repeated reoperation on rats included in long-term investigations is not possible because of the increasing formation of scar tissue and adhesions at the site of the distal aorta. Consequently, noninvasive ultrasonic Doppler measurement was investigated to determine whether this method could provide accurate information about the patency of an implanted prosthesis. A total of 37 rats with 10-cm-long prostheses implanted in the aorta (groups C nonsupported prostheses, n = 12; and D supported prostheses, n = 25), eight normal nonoperated controls (group A), and three rats with a ligated aorta (negative controls, group B) were studied over a period of 12 weeks. The Dopplerrecordings obtained in the normal animals served as controls for the recordings of rats with an implanted prosthesis. A prosthesis was considered patent if the Dopplermeasurements obtained from the femoral artery resembled that of the normal pattern. In seven cases a prosthesis was suspected to be occluded since the Dopplermeasurements resembled those obtained after aortic ligation. Autopsy confirmed the Dopplermeasurements in all cases. No Dopplermeasurements returned to normal in the femoral artery in the aorta-ligated rats even after longer periods post-operation. It is concluded that Dopplermeasurements can accurately provide information about the patency of a vascular prosthesis implanted in the rat aorta.

Animals↗
PubMed1987

The formation of a neo-intima in textile prostheses implanted in the aorta of rats and dogs.

The formation of a neo-intima in textile prostheses implanted in the rat and dog aorta was studied by means of light- and scanning electron microscopy. Two independent cellular layers (the superficial and deep ingrowth layers) developed on the free surface and under the fibrin layer initially deposited on the inner surface of the prostheses. The superficial ingrowth layer invades the prosthesis from both the proximal and distal aortic stumps and extends over the primary fibrin layer, or replaces it. This layer consists mainly of smooth muscle cells of the triangular aortic type covered by endothelial-like cells. The deep ingrowth layer originates from cellular elements of the prosthetic bed. Fibroblasts, myofibroblasts and spindle-shaped smooth muscle cells invade the fibrin layer through the interstices of the fabric structure of the prosthesis. Precursors of endothelial cells, however, are absent from this population. The superficial and the deep ingrowth layers may become joined by progressive replacement of the fibrin layer, but remain distinguishable because of their different cellular components. When a continuous cellular layer is established on the inner surface of the prosthesis, and this is then covered by endothelial-like cells, the neo-intima formed remains stable during long-term studies.

Animals↗
PubMed1986

The inner prosthetic surface structure and re-endothelialization: an experimental study in the rat using two types of microvascular prostheses for aortic implantation.

Two types of microvascular prostheses were implanted in the rat infrarenal aorta. Operations were carried out with clean, nonsterile instruments under ether anesthesia. Anastomoses were made with a continuous 8-0 suture. In group A, a 1-cm-long piece of expanded polytetrafluorethylene (PTFE) and in group B a 1-cm-long fibrous polyurethane prosthesis were implanted. Both groups consisted of 18 rats. Three rats from each group were killed at days 3, 5, 10, 20, 40, and 60 postimplantation. Prostheses were examined by scanning electron and light microscopy for the re-endothelialization. All prostheses in both groups were patent at the time of death. Re-endothelialization started in both types of prostheses the fifth day after implantation and had advanced 1-3 mm in the PTFE prostheses at day 60. However, in the fibrous polyurethane prostheses, re-endothelialization progressed and a complete new lining was achieved between days 20 and 40 postimplantation. The endothelium/neointima in the fibrous prosthesis was firmly anchored onto the prosthetic wall by means of cellular protrusions between the polyurethane fibers. In contrast to this observation, the endothelium/neointima developed in the PTFE prostheses was not anchored to the wall of the prosthesis. It is emphasized that the development of a new lining in a prosthesis may reduce the risk of endogenous, hematogenous infections. From the results of this study, we have concluded that there is a correlation between the inner surface structure and the extent of the re-endothelialization of a prosthesis. A prosthesis with a fibrous structure is much more rapidly and completely re-endothelialized than an expanded PTFE prosthesis.

Animals↗
PubMed1985

Three years experience with experimental implantation of fibrous polyurethane microvascular prostheses in the rat aorta.

The results of a 3-year study in which a series of 355 implantations of 1-cm-long fibrous polyurethane microvascular prostheses into the infrarenal aorta of the rat (group A) were evaluated with respect to patency and formation, structure, and fate of the neo-intima. Rats were sacrificed at various intervals from 1 day to 2 years in order to obtain a time-related impression of the re-endothelialization and stability of the neo-intima. A second series of 51 implants was done with prostheses 10 cm in length, placed in a 1.5-cm loop in the abdominal aorta (group B). An overall patency rate of 92.7% was achieved in group A. Initially, eight technical failures caused early thrombosis of the prostheses. Sixteen prostheses became infected and subsequently occluded. The overall patency in group B was 52.9%, due to kinking from adhesion formation and normal growth of the rat. In both the long and short prostheses, a continuous multilayered neo-intima developed, growing from the aortic stumps into the prosthesis from both sides. According to the growth rate of 0.3 mm/day, a 1-cm prosthesis was re-endothelialized after +/- 20 days and a 10-cm prosthesis after +/- 9 months. Once developed, the neo-intima, consisting of myofibroblasts and smooth muscle cells covered with a flat endothelium, remained stable and continuous, throughout the observation period. The neo-intima was firmly anchored onto the prosthetic wall by means of cellular protrusions extending between the polyurethane fibres. The significance of rapid healing of an implanted prosthesis is emphasized with respect to preventing (late) hematogenous, endogenous infection of the prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Significance of the inner-surface structure of small-caliber prosthetic blood vessels in relation to the development, presence, and fate of a neo-intima. A morphological evaluation.

Microvascular prostheses with three different inner surface structures were examined morphologically 1-18 months after implantation to evaluate the presence and structure of the neo-intima. Fibrous polyurethane tubes (length: 5-10 mm, inner diameter: 1.5 mm) were implanted in the rat abdominal aorta in group A with a fibrillar inner structure (pore sizes 20-50 microns), and in group B the inner fibrillar structure was coated with an impermeable continuous silicon sheet. Expanded polytetrafluorethylene vascular prostheses (length: 40 mm, inner diameter: 4 mm) were implanted in the dog carotid artery (group C). The specimens were examined by light microscopy and scanning electron microscopy. A continuous and permanent neointima was only found in the prostheses with the porous fibrillar inner structure (group A). The thin new lining sheet was well attached to the prosthetic wall by cellular protrusions. In the silicon-coated prostheses (group B) also a continuous neo-intima had developed which, however, was irregular, thicker, and not anchored to the prosthetic wall. The expanded polytetrafluorethylene prostheses (group C) showed also after 1 year only incomplete lining with a neo-intima. Fresh blood cell deposits could be observed in the unlined prosthetic wall. It is concluded that a continuous lining of vascular grafts with a thin neo-intima is only achieved if the cells invading the prostheses from the anastomotic areas can anchor their cytoplasmic protrusions onto an appropriately structured inner surface. If these anchoring facilities are not provided, the unattached neo-intima will thicken, interfering with the patency of these microvascular prostheses, or fragments of the neo-intima or alternatively mural thrombi may constantly strip off and embolize.

Animals↗
PubMed1984

Patency and neo-intima development in 10 cm-long microvascular polyurethane prostheses implanted into the rat aorta.

Microvascular fibrous polyurethane prostheses (inner diameter 1.5 mm, length 10 cm) were implanted in the abdominal aorta of rats. The prostheses were fixed in a loop. All rats (n = 37) were reoperated 6 weeks after implantation to verify the patency of the prostheses. Eight prostheses were obliterated from various causes. The remaining 29 prostheses were found to be patent 3 months after implantation, which gives a patency rate of 79%. Six weeks and 3 months after implantation 7 and 4 rats, respectively, with patent prostheses were sacrificed. The remaining 18 rats of this study are still alive, more than 4 months after implantation, and will be included in long-term observation studies. The prostheses were examined using both light and scanning electron microscopy. The patent prostheses exhibited macroscopically a clear and transparent inner surface. No obliterative processes could be found either macroscopically or microscopically. Neo-intima ingrowth had advanced +/- 10 mm into the prostheses over the anastomotic line from both ends 3 months after implantation, and was continued by a single endothelium layer for several centimeters. An acellular, stable fibrin film was found inbetween the cellular lining. The neo-intima was anchored at the prosthesis by cellular protrusions extending between the polyurethane fibers. Though 10 cm long prostheses were implanted under unfavorable hemodynamic conditions, a patency rate of 79% was achieved, both 6 weeks and 3 months after implantation. This patency rate could have been higher if evident technical failures had been avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Evaluation of the patency rate of fibrous microvascular polyurethane prostheses after implantation in the rat aorta.

Two types of fibrous polyurethane prostheses with different compliances were implanted into the rat aorta with interrupted sutures and a running suture line. Excluding two technical failures, one unexplained death, and three infected prostheses, both groups (n = 21) showed a patency rate of 100%, up to 6 months after implantation. Rapid reendothelialisation occurred, and a stable neo-intima was formed. Compliance of the prostheses, as well as the suture technique used, has proven to be an unimportant factor in the rat aorta model, probably due to the low magnitude of the pulsations of the rat aorta. The experience of the surgeon with microsurgical techniques seems to be an underestimated factor in determining patency rates of microvascular prostheses.

Animals↗
PubMed1983

Plasmodium berghei: influence on granulopoiesis and macrophage production in BALB/c mice.

Granulocyte and macrophage progenitor cells forming colonies in vitro (GM-CFC) from bone marrow, spleen, and peripheral blood of BALB/c mice infected with Plasmodium berghei were cultured at various times postinfection in a viscous, 0.8% methylcellulose system. The numbers of GM-CFCs from bone marrow increased gradually during the first week of infection, reaching a maximum around the tenth day of the disease. Subsequently, a rise of GM-CFCs in cultures of nucleated cells from the peripheral blood was observed and, with some delay, in spleen cell cultures also, with a maximum around the end of the second week. After the tenth day of malaria infection a fall of colony frequency in bone marrow-derived cells took place, leading to subnormal values of GM-CFCs during the third week of infection. Subsequently, a decrease in the spleen cell cultures followed, but colony numbers did not fall to normal values. The general increase in GM-CFCs in the different organs was preceded by a rise in serum levels of colony-stimulating activity (CSA), attaining a maximum 1 week after P. berghei inoculation. During the following period the CSA levels fell and reached normal values around the seventeenth day of the disease. Chemotherapy with chloroquine started on the fifteenth day of infection, when GM-CFCs in the bone marrow have dropped to normal values, stopped their further decrease. In the spleen a gradual normalization took more than 2 weeks. A challenge infection evoked an elevation of GM-CFC numbers in the bone marrow and in the spleen during the first 10 days in only about 50% of immune mice. The reaction was immediate in some animals, but generally lower and of shorter duration than during primary infection. The results have indicated that a lethal P. berghei infection in mice caused a transient increase in production of CSA followed by a general recruitment of GM-CFCs in all hemopoietic organs.

Animals↗