Biomedical subjects

Stephan Korom

Publications and source records attributed to Stephan Korom.

5 recordsLinked to original sources

PubMed2003

Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography.

BACKGROUND: We compared the diagnostic accuracy of integrated positron-emission tomography (PET) and computed tomography (CT) with that of CT alone, that of PET alone, and that of conventional visual correlation of PET and CT in determining the stage of disease in non-small-cell lung cancer. METHODS: In a prospective study, integrated PET-CT was performed in 50 patients with proven or suspected non-small-cell lung cancer. CT and PET alone, visually correlated PET and CT, and integrated PET-CT were evaluated separately, and a tumor-node-metastasis (TNM) stage was assigned on the basis of image analysis. Nodal stations were identified according to the mapping system of the American Thoracic Society. The standard of reference was histopathological assessment of tumor stage and node stage. Extrathoracic metastases were confirmed histopathologically or by at least one other imaging method. A paired sign test was used to compare integrated PET-CT with the other imaging methods. RESULTS: Integrated PET-CT provided additional information in 20 of 49 patients (41 percent), beyond that provided by conventional visual correlation of PET and CT. Integrated PET-CT had better diagnostic accuracy than the other imaging methods. Tumor staging was significantly more accurate with integrated PET-CT than with CT alone (P=0.001), PET alone (P<0.001), or visual correlation of PET and CT (P=0.013); node staging was also significantly more accurate with integrated PET-CT than with PET alone (P=0.013). In metastasis staging, integrated PET-CT increased the diagnostic certainty in two of eight patients. CONCLUSIONS: Integrated PET-CT improves the diagnostic accuracy of the staging of non-small-cell lung cancer.

Aged↗

PubMed2003

CD26/DPP IV in experimental and clinical organ transplantation.

UNLABELLED: The T-cell activation-Ag CD26 possesses dipeptidyl peptidase IV (DPP IV) enzymatic activity. Costimulatory efficacy and immunocompetence are associated with the enzymatic activity. GOALS: In models of experimental cardiac allograft transplantation (HTx), we analyzed the role of CD26/DPP IV during organ rejection. Also, we investigated CD26 enzymatic and cellular expression in human recipients of kidney transplants (Tx). MATERIAL AND METHODS: Heterotopic HTx in rats, models of acute and accelerated rejection. Monitoring of DPP IV serum levels and humoral immunity. Propro-diphenyl phosphonate was employed to inhibit DPP IV activity during rejection. In a prospective study, surface expression of CD26, 3, 4, 8, 45, 122 and ADA on PBL and DPP IV serum activity were measured in kidney recipients for 24 months post-transplantation. RESULTS: Acute rejection was . associated with increased serum DPP IV activity (p < 0.005). Specific inhibition abrogated acute (p < 0.0001) and accelerated (p < 0.01) rejection, impairing cytotoxicity and allospecific Ig-synthesis. Kidney recipients displayed a significant drop in CD26 expression on PBL for up to 18 months postoperatively (p < 0.001). CD4, 8, 45, 122 and ADA expression kinetics were only briefly affected. DPP IV enzymic activity stayed depressed for at least 12 months (p < 0.001). CONCLUSION: CD26/DPP IV is pivotal in T-cell mediated immune responses toward allo-Ag. In clinical transplantation, engraftment/immunosuppression are reflected by CD26 cellular and enzymatic expression posttransplantation and may serve as an indicator for immunomodulation.

Animals↗

PubMed2003

The influence of the rapamycin-derivate SDZ RAD on the healing of airway anastomoses.

OBJECTIVE: Among the many immunosuppressive effects of SDZ RAD (40-0(2-hydroxyethyl)-rapamycin), a rapamycin derivative, is the inhibition of fibroblast proliferation. Since the long-term success of lung transplantation is limited by the development of bronchiolitis obliterans, a fibroblast-associated progressive luminal obstruction of the terminal bronchioli, the use of SDZ RAD as immunosuppressive in pulmonary graft recipients may counteract this process. However, reduction of fibroblast activity, posttransplant, may impair the healing of the bronchial anastomoses. MATERIALS AND METHODS: The cervical trachea in pigs was denuded, divided and re-anastomosed with Prolene 4-0 single stitches. Control animals (group 1, n=4) were without, and study animals (group 2, n=6) were with SDZ RAD therapy (1.25 mg/kg/day, p.o., 14 days). After 14 days, the pigs were sacrificed. The anastomoses were examined histologically, and breaking strength of tracheal strips of 5-mm width was measured. RESULTS: All animals survived without complications. Serum levels of SDZ RAD were 30.9+/-8.7 ng/ml (recommended level 20-40 ng/ml). All anastomoses healed macroscopically without difference between the two groups. Breaking strength was significantly lower in the treated animals (group 1 vs. group 2: 11.75+/-0.35 vs. 7.69+/-1.39 N, P=0.01). Histology did not show a significant change in histoarchitecture between the groups. CONCLUSIONS: Although SDZ RAD significantly reduced the breaking strength of the tracheal anastomosis, no obvious histological differences between treated and untreated animals could be detected. Since this model does not reflect the clinical situation, further investigations are necessary to reveal the effect of SDZ RAD on airway wound healing in concert with a contemporary clinically used multidrug immunosuppressive regimen in allograft recipients.

Anastomosis, Surgical↗

PubMed2003

Tissue engineered cartilage generated from human trachea using DegraPol scaffold.

OBJECTIVE: To date numerous attempts have been undertaken to conquer the challenging problem of reconstructing long segmental tracheal defects, as yet without lasting success. Recently, employing concepts of tissue engineering in animals, cartilage-like constructs were transplanted in vivo. However, both the feasibility of fabricating tracheal replacements and the use of human tracheal chondrocytes (HTC) for tissue engineering are still under investigation. In this study, we optimized isolation and cultivation techniques for human tracheal cartilage, assessing the feasibility of seeding these cells onto a novel, three-dimensional (3-D) polyester-urethane polymer (DegraPol). METHODS: Human tracheal cartilage was harvested from the trachea of lung donors, digested in 0.3% collagenase II, and the condrocytes serially passaged every 7-9 days. Cells were also cultivated over agar plate during the total 6-8 weeks expansion phase. Thereafter, chondrocytes were seeded onto DegraPol (pore sizes 150-200 microm) with a seeding density of 2.4 x 10(7)/ml, and chondrocyte-polymer constructs maintained during in vitro static culture. RESULTS: HTC displayed stable proliferation kinetics in monolayer culture with positive expression of collagen type II. Following polymer seeding, both cellular proliferation and extracellular matrix (ECM) production, as measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and glycosaminoglycan assays, continued over extended culture. Active growth of HTC on DegraPol was further demonstrated by Alcian blue staining, with the histomorphological appearance of the construct resembling that of native cartilage. Scanning electron microscopy showed chondrocyte growth and ECM synthesis both on the surface and inside the porous scaffold, with a dense cell layer on the surface of the scaffold and a lower cell distribution in the scaffold's interior. CONCLUSIONS: The harvested chondrocytes from human trachea cartilage expand well in vitro and possess the ability to form new cartilage-like tissue when seeded onto DegraPol matrix. However, improved culture conditions are needed to permit cellular growth throughout cell-polymer constructs.

Absorbable Implants↗

PubMed2002

Prevention of recurrent empyema after pneumonectomy for chronic infection.

OBJECTIVES: Pneumonectomy in chronic pulmonary infection with empyema is associated with a high mortality rate and an increased risk of recurrent empyema. The surgical resection is technically demanding, and successful management continues to be a challenge. METHODS: We evaluated a concept which combines (pleuro-)pneumonectomy or completion pneumonectomy with surgical debridement of the pleural cavity and packing with povidine-iodine soaked dressings. The debridement and packing is repeated in the operating theater after 48 h until the chest cavity is macroscopically clean. Finally, the pleural space is obliterated with antibiotic solution. RESULTS: Between February 1997 and October 2000, 11 patients (average age of 59 years, ranging from 25 to 84) with destroyed lung caused by tuberculosis (six), aspergilloma (two), bronchiectasis (one), esophago-pleural fistula (one) or broncho-pleural fistula after lobectomy for bronchial carcinoma (one) and ongoing chronic infection with acute empyema (ten) (25-2500 days between first and definitive therapy) were treated. Pleural culture findings showed Aspergillus in four, Mycobacterium in two, Enterococcus in two, Candida in one and Staphylococcus in one, respectively. The mean number of interventions was 2.9 (2-4). The chest was definitively closed in all patients within 1 week. The mean hospitalization time was 19 days (9-31 days). In the follow-up (10-54 months), there was no recurrence of empyema. One patient (84 years) died at day 31, due to sepsis. CONCLUSIONS: Pneumonectomy combined with repeated surgical debridement and antimicrobial therapy enables the successful treatment of chronic pulmonary infection with empyema within a short time period.

Adult↗