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Biomedical subjects

G Koukoulis

Publications and source records attributed to G Koukoulis.

At least 19 recordsLinked to original sources
PubMed2008

Echocardiographic evaluation of mitral tethering for 'chordal cutting' procedure.

'Chordal cutting' is a recently proposed surgical option for the treatment of functional mitral regurgitation due to leaflet tethering. With this technique the surgeon sections second order chordae, restores leaflet's convexity towards the left atrium and eliminates mitral incompetence. Preoperative assessment of tethering mechanism, degree of leaflet distortion, surface of coaptation, annular dilation, origin and quantification of valve incompetence by echocardiographic means is essential in indicating this surgical option. Intraoperative transesophageal evaluation is crucial to assess the morphology and the absence or degree of residual incompetence after procedure.

Aged↗
PubMed2006

The effects of acute exercise on serum adiponectin and resistin levels and their relation to insulin sensitivity in overweight males.

The purpose of this study was to investigate the effects of a submaximal aerobic exercise bout on adiponectin and resistin levels as well as insulin sensitivity, until 48 h post-exercise in healthy overweight males. Nine subjects performed an exercise bout at an intensity corresponding to approximately 65% of their maximal oxygen consumption for 45 min. Adiponectin, resistin, cortisol, insulin, glucose and insulin sensitivity were measured prior to exercise, immediately after exercise as well as 24 and 48 h after exercise. Data were analyzed using repeated measures ANOVA while Pearson's correlations were performed to identify possible relationship among the assessed variables. There were no significant differences for adiponectin (microg ml(-1)) [pre, 3.61(0.73); post, 3.15(0.43); 24 h, 3.15(0.81); 48 h, 3.37(0.76)] or resistin (ng ml(-1)) [pre, 0.19(0.03); post, 0.13(0.03); 24 h, 0.23(0.04); 48 h, 0.23(0.03)] across time. Insulin sensitivity increased and insulin concentration decreased significantly only immediately after exercise. Furthermore, no significant correlations were observed among the variables assessed except for the expected between insulin level and insulin sensitivity. These results indicate that a submaximal aerobic workout does not result in significant changes in adiponectin and resistin up to 48 h post-exercise. Furthermore, it appears that adiponectin or resistin is not associated with insulin sensitivity.

Adiponectin↗
PubMed2005

Correlation of estrogen receptor beta gene polymorphisms with spinal bone mineral density in peri- and post-menopausal Greek women.

Estrogens play a significant role in bone physiology. Their action is mainly exerted through their receptors. Estrogen receptor alpha (ERalpha) plays a major role in bone homeostasis and there is evidence suggesting that estrogen receptor beta (ERbeta) has also an effect on BMD. We investigated the possible effect of two ERbeta gene polymorphisms on spinal bone mineral density (BMD) and metabolic bone markers in Greek women. Spine BMD as well as biochemical bone markers were measured in 147 healthy peri- and post-menopausal women [mean age (S.D.) 54 (7.9) years]. Genotyping was performed for two restriction fragment length polymorphisms (RFLPs) of ERbeta gene, RsaI in exon 5 and AluI in exon 8. For each polymorphism studied the cohort was divided into two groups: the "wild-type" group (RR and AA, respectively) and the "carrier" group including subjects with at least one allele with the restriction site (Rr&rr and Aa&aa, respectively). The distribution of RsaI genotypes was RR: 91.2% (n = 134), Rr: 8.2% (n = 12), and rr: 0.6% (n = 1) and of AluI genotypes AA: 36.7% (n = 54), Aa: 57.2% (n = 84), and aa: 6.1% (n = 9). No linkage disequilibrium was found between the two polymorphic sites studied. Spine BMD did not differ significantly in the two groups of either polymorphism, after adjusting for age, weight, height, and years since menopause [mean BMD (S.D.) for RR 0.841 (0.17) g/cm(2) versus Rr&rr 0.798 (0.13) g/cm(2), p = 0.25, and mean BMD (S.D.) for AA 0.828 (0.16)g/cm(2) versus Aa&aa 0.848 (0.17) g/cm(2), p = 0.32]. No significant differences were noted in metabolic bone markers except for a marginal difference of RR versus Rr/rr in urinary hydroxyproline/creatinine ratio [median (IQR) 3.88 (6.04) micromol/mmol in RR versus 8.2 (4.32) micromol/mmol in Rr/rr, p = 0.05]. Furthermore, no interaction between the two polymorphisms on BMD was found. In conclusion, in a Greek female post-menopausal population, the two ERbeta gene polymorphisms were not associated with BMD, or metabolic bone markers.

Absorptiometry, Photon↗
PubMed2004

Apolipoprotein E polymorphism is not associated with spinal bone mineral density in peri- and postmenopausal Greek women.

OBJECTIVES: A number of studies have shown a positive relation between ApoE gene and osteoporosis or fracture risk but this finding has not been uniform in all populations studied. The aim of the present study was to determine the possible effect of ApoE gene polymorphism on spinal bone mineral density and metabolic bone markers in Greek women. METHODS: One hundred and forty-seven healthy peri- and postmenopausal women (mean age 54.3 +/- 7.8 years) participated in the study. In all participants, ApoE gene genotype was determined and spinal bone mineral density (BMD) as well as biochemical bone markers were measured. The ApoE genotypes distribution was 0.7% (n = 1) for E2/2, 5.4% (n = 8) for E2/3, 2% (n = 3) for E2/4, 73.5% (n = 108) for E3/3, 16.3% (n = 24) for E3/4 and 2% (n = 3) for E4/4. Participants were divided in two groups according to the presence of the E4 haplotype: E4 carriers (n = 30) and E4 non-carriers (n = 117). RESULTS: Spinal BMD was similar in the two groups, after adjusting for age, weight, height and years since menopause (mean +/- S.D., 0.835 +/- 0.16 g/cm2 in E4 non-carriers versus 0.831 +/- 0.16 g/cm2 in E4 carriers, P = 0.99). Serum osteocalcin levels did not differ significantly in the two groups (median (interquartile range, IQR), 0.55 (0.58) nmol/l in E4 non-carriers versus 0.51 (0.43) nmol/l in E4 carriers), whereas urinary hydroxyproline/creatinine ratio was significantly higher in the E4 non-carriers group (median (IQR), 5.18 (6.04) micromol/mmol in E4 non-carriers versus 1.73 (3.45) micromol/mmol in E4 carriers, P < 0.01). Urinary pyridinoline/creatinine and deoxypyridinoline/creatinine ratios, measured in a subgroup of 51 women, were similar between ApoE carriers and non-carriers, respectively (median (IQR), 25.1 (9.3) nmol/mmol in E4 non-carriers versus 21.8 (7) nmol/mmol in E4 carriers and 6.7 (3.1) nmol/mmol in E4 non-carriers versus 7 (2.2) nmol/mmol in E4 carriers). CONCLUSION: In conclusion, in a Greek female postmenopausal population, ApoE gene does not seem to play an important role in determining BMD and neither does it affect the majority of metabolic bone markers.

Adult↗
PubMed2004

The effects of a single bout of exercise on resting energy expenditure and respiratory exchange ratio.

We investigated the effects of a single bout of aerobic and resistance exercise of similar relative intensity and duration on resting energy expenditure (REE) and substrate utilisation. Ten young healthy males volunteered [age 22 (1.8) years, weight 76 (7.9) kg, height 176 (4.1) cm, percentage body fat 10.5 (4.0)%; mean (SEM)]. They randomly underwent three conditions in which they either lifted weights for 60 min at 70-75% of 1-RM (WL), ran for 60 min at 70-75% of maximal oxygen intake (R) or did not exercise (C). REE and substrate utilisation, determined via respiratory exchange ratio ( R), were measured prior to exercise, and 10, 24, 48 and 72 h post-exercise. It was revealed that REE was significantly elevated ( P<0.05) 10 and 24 h after the end of WL [2,124 (78) and 2,081 (76) kcal, respectively] compared to pre-exercise [1,972 (82) kcal]. REE was also significantly increased ( P<0.05) 10 and 48 h after the completion of R [2,150 (73) and 1,995 (74) kcal, respectively] compared to pre-exercise data [1,862 (70) kcal]. R was lower 10 and 24 h following either WL or R [0.813 (0.043); 0.843 (0.040) and 0.818 (0.021); 0.832 (0.021), respectively] compared to baseline measurements [0.870 (0.025) and 0.876 (0.04), respectively]. Creatine kinase was significantly elevated ( P<0.05) 24 h after both WL and R, whereas delayed onset muscle soreness became significantly elevated ( P<0.05) 24 h after only WL. There were no significant changes for any treatment in thyroid hormones (T(3) and T(4)). These results suggest that a single bout of either WL or R exercise, characterised by the same relative intensity and duration, increase REE and fat oxidation for at least 24 h post-exercise.

Adult↗
PubMed2001

Seventh Day Syndrome--acute hepatocyte apoptosis associated with a unique syndrome of graft loss following liver transplantation.

AIM: The aim of this study is to describe a unique 7th day syndrome (7DS), quite different from other causes of post-transplantation allograft dysfunction in a group of orthotopic liver transplant (OLT) patients who needed retransplantation. METHODS: A retrospective analysis of 594 consecutive OLT over an 8-year period revealed that 10 patients developed allograft dysfunction approximately 7 days following an initially normal graft function. RESULTS: The features included: (a) severe liver failure; (b) sudden peak of extremely high liver enzymes at approximately day 7; (c) serial liver biopsy findings of central lobular hemorrhage with minimal inflammatory cell infiltrate and (d) an explant with no evidence of vascular thrombosis. The biochemical and morphometric pathological data of these patients were compared with data of patitents who had early acute rejection (AR), hepatic artery thrombosis (HAT), primary nonfunction (PNF), severe sepsis and no dysfunction. Lastly, serial liver core biopsies and explants were tested for evidence of apoptosis, which revealed a significantly higher number of apoptotic hepatocytes in 7DS compared to all control groups. CONCLUSIONS: Seventh Day Syndrome is a distinct entity associated with early graft dysfunction characterized by a marked apoptosis of hepatocytes. Fas receptor activation or other pathways of program cell death may be implicated in occurrence of 7DS.

Acute Disease↗
PubMed2001

Immunohistochemistry of the liver and biliary tree in extrahepatic biliary atresia.

BACKGROUND: Progressive destruction of intrahepatic bile ducts may determine outcome in extrahepatic biliary atresia (EHBA) despite successful portoenterostomy. The aim of this study was to characterize the inflammatory infiltrate of a large series of cases of biliary atresia and relate these findings to clinical outcome. METHODS: Immunohistochemical analysis was performed on frozen tissue sections of extrahepatic biliary tree and liver biopsies obtained (August 1996 to March 1998) from 28 infants with EHBA and 8 liver biopsy specimens from age-matched controls with other cholestatic liver disorders. A semiquantitative scoring system was designed to evaluate the staining with a panel of antibodies to the CD4, CD8, CD25, CD56, CD68, CD71 antigens and to HLA-DR, ICAM-1, VCAM-1, E-selectin and LFA-1. The infants then underwent followup prospectively and divided into 2 prognostic groups at 12 months postoperatively: those who had cleared their jaundice (graded as a good outcome [n = 19]), and those who required liver transplantation or who had failed to clear their jaundice (defined as > 50 micromol/L; graded as poor outcome [n = 9]). RESULTS: CD4(+) lymphocytes and CD56(+) (NK cells) predominated in the liver of infants with EHBA as compared with controls. The infiltrating cells exhibited marked proliferation (CD71 expression) and activation (particularly LFA-1 but also CD25 expression). A smaller subpopulation of the cells also expressed VCAM and E-selectin. HLA-DR was strongly expressed on Kupffer cells and to a lesser extent on proliferating bile ducts and sinusoidal endothelium. Expression of the majority of markers was lower in the remnant bile duct tissue than in the liver of EHBA (P <.05) with only HLA-DR and LFA-1 (on infiltrating cells) and ICAM (on endothelium) expressed strongly in the remnant bile duct tissue. Although quantitatively less pronounced, all of these immunohistochemical features also were noted in non-EHBA cholestatic liver tissue. A good outcome at 12 months was associated with lower CD68 (macrophage) expression in both the liver (P <.05) and biliary tree (P <.05) and with reduced expression of ICAM-1 (P =.05) on infiltrating cells in the biliary remnant. CONCLUSIONS: Immunohistochemical patterns of immune-mediated liver injury and inflammation were prevalent features at the time of portoenterostomy. They were neither exclusive to nor characteristic of EHBA. A reduction in the expression of the macrophage marker (CD68) within the liver and biliary remnants and reduction of ICAM-1 expression on infiltrating cells in the biliary remnants appear to be associated with a better postoperative prognosis.

Antigens, CD↗
PubMed2001

Obliterative muscularization of the small bowel submucosa in Crohn disease: a possible mechanism of small bowel obstruction.

CONTEXT: The pathology of small bowel obstruction in Crohn disease has not been studied extensively. Stricture formation has been attributed mainly to fibrosis, although muscularization of the submucosa has been discussed previously. OBJECTIVE: To identify additional pathologic changes in Crohn disease that could be involved in the formation of strictures. DESIGN: We reviewed 50 ileal resections from patients with Crohn disease. The histopathologic slides were reviewed initially without knowledge of the macroscopic or clinical findings. We identified an unusual muscular proliferation that we refer to as obliterative muscularization of the submucosa, defined as a thick and continuous muscle layer from the mucosal base to the muscularis propria that is at least 1 cm in length. Subsequently, histopathologic findings were correlated with macroscopic and clinical findings. RESULTS: Obliterative muscularization of the submucosa was present in 14 specimens, and in 11 of these 14 it was topographically restricted to strictures. Submucosal fibrosis was observed in sections from adjacent regions. Obliterative muscularization of the submucosa, including thick-walled vessels and hyperplastic nerves but not prominent scarring, was more common in specimens with strictures; the difference was statistically significant (P <.001). CONCLUSIONS: Obliterative muscularization of the submucosa may be pathogenetically involved in the formation of strictures either directly by causing a sustained spasm, or indirectly by minimizing the vasoprotective role of the submucosa, impairing repair and enhancing scarring.

Adolescent↗
PubMed2000

Superoxide dismutase activity in children with chronic liver diseases.

BACKGROUND/AIMS: Liver disease in infancy has multiple etiologies. As reactive oxygen intermediates are involved in several types of tissue damage, we have investigated whether different forms of liver disease in infancy are associated with increased free radical generation, using an indirect approach in which superoxide dismutase (a free radical scavenger) activity is determined in the liver tissue. METHODS: A total of 48 liver biopsies performed at diagnosis were evaluated retrospectively. Nine infants had biliary atresia, eight Alagille syndrome, seven alantitrypsin deficiency and 12 cryptogenic hepatitis. As controls we studied 12 biopsies with normal histology obtained from seven children with portal vein thrombosis and five children who underwent biopsy for management reason but had no liver disease. Superoxide dismutase activity in liver biopsy specimens was measured using the cytochrome C method by spectrophotometry and expressed as U SOD/mg protein. RESULTS: Superoxide dismutase activity was significantly increased in biliary atresia (1.25 +/- 0.56 U SOD/mg protein, p<0.0001) and Alagille syndrome (1.31 +/- 0.56 U SOD/mg protein, p<0.0001) as compared with al-antitrypsin deficiency (0.75 +/- 0.3 U SOD/mg protein), neonatal hepatitis (0.72 +/- 0.37 U. SOD/mg protein) and normal controls (0.4 +/- 0.7 U. SOD/mg protein). The highest level of SOD activity was found, however, in control children with portal vein thrombosis (2.09 +/- 0.96 U SOD/mg protein; p<0.0001 as compared to the other groups). CONCLUSION: Superoxide dismutase, a key enzyme in free radical protection, is increased significantly in the liver tissue of infants with cholestatic liver disease due to bile duct damage and in children with portal vein thrombosis, suggesting that products of free radical reactions are involved in the pathogenesis of these disorders.

Alagille Syndrome↗
PubMed1999

Differentiated thyroid cancer: a retrospective analysis of 832 cases from Greece.

OBJECTIVE: To analyse the initial manifestations, pathological findings, therapy, outcome and prognostic factors in patients with papillary and follicular carcinoma. PATIENTS: 832 patients with well differentiated thyroid carcinoma managed in our department during a period of 30 years (1965-1995). Follow-up data were available for 609 patients for a mean of 5.5 years (range 1-38 years), the remainder having been lost to follow-up. RESULTS: The patients were 677 (81%) with papillary and 155 with follicular carcinoma. They were predominantly female (75%), presenting mainly with a single nodule (53%), while at the time of diagnosis 72% had intrathyroidal carcinomas (class I), 17% had nodal metastases (class II), 7% soft tissue invasion (class III) and 4% distant metastases (class IV). Fifty-five percent of the patients had a complete thyroidectomy (36% had a near total or total thyroidectomy and 19% near total or total thyroidectomy plus block dissection), 2.6% received external radiotherapy and 94% had radioactive iodine as part of the treatment of the original disease. Kaplan-Meier survival analysis was used to calculate both cancer related mortality and disease free survival in the patients followed-up. Although mortality (21 cancer-related deaths) was slightly higher for follicular than papillary carcinoma (10% vs. 5% and 16% vs. 10% in 10- and 15-year survival, respectively) the difference was not statistically significant. Extent of disease at diagnosis, male sex, tumour size and age > 60 years affected probability of cancer death. Cox's proportional hazard regression analysis for disease free survival showed that adverse independent prognostic factors were, for papillary carcinoma, male sex, class II or higher, tumour size > 1 cm and age > 60 years, while for follicular, class III or higher, size > 4 cm and age > 40 years. CONCLUSIONS: We conclude that there is a higher prevalence of follicular carcinoma in our country probably due to a moderate degree of iodine deficiency still existing in Greece. Age and extent of disease at diagnosis were important prognostic factors affecting morbidity and mortality, whereas sex, tumour features and histological type were of minor importance. All these prognostic factors and their relative importance should be taken in consideration in the management of this disease.

Adenocarcinoma, Follicular↗
PubMed1997

Cryosurgery of breast cancer.

OBJECTIVE: To determine the feasibility and efficacy of cryosurgery of breast cancer. DESIGN: In phase 1, carcinogen-induced mammary adenocarcinomas in 13 Sprague-Dawley rats were treated by cryosurgery and were then examined for histopathologic change. In phase 2, transplantable mammary adenocarcinomas in 50 DBA/IJ mice were treated by cryosurgery to determine the effect of varying tumor temperatures, and duration and number of freeze-thaw cycles on tumor viability. In phase 3, 2- to 3-cm ultrasound-monitored cryolesions were formed in the breasts of 4 dogs and 4 sheep. These animals were followed up for procedure-related complications; the histopathologic necrosis of the cryolesions were correlated with the ultrasound images. Based on the results of these experiments, ultrasound-guided cryosurgery of breast cancer was initiated in a human clinical trial. RESULTS: In phase 1, a single, short-term (< 7 minutes) freeze killed only tumors smaller than 1.5 cm in diameter, despite an apparent decrease to -40 degrees C at the periphery of each tumor. In phase 2, varying the peripheral tumor temperature to as low as -70 degrees C, using a single, short-term (< 7 minutes) freeze did not alter the results from phase 1. If the ice ball fully encompassed the tumor, however, maintaining it for at least 15 minutes achieved 100% tumor kill independent of tumor size. In phase 3, creation of a reproducible ultrasound-monitored cryolesion was facilitated when 2 freeze-thaw cycles were performed. No procedure-related complications were noted. In the human trial, 2 invasive lobular carcinomas from 1 patient were treated by cryosurgery and were negative for persistent tumor by core needle biopsy performed 4 and 12 weeks after a well-tolerated procedure. CONCLUSIONS: In situ breast cryosurgery has been proved to be feasible and efficacious in small and large animal studies and has been successfully performed in 1 patient with breast cancer. The results of this study suggest that ultrasound-guided cryosurgery of breast cancer warrants further investigation.

Adenocarcinoma↗
PubMed1997

Autoimmune hepatitis: a histological variant associated with prominent centrilobular necrosis.

A patient presented with pruritus and recent elevation of aminotransferases. The case fulfilled most of the criteria for the diagnosis of autoimmune hepatitis and achieved clinical and complete biochemical response to steroid therapy. However, the liver biopsy specimen revealed an unusual histological pattern consisting of severe centrilobular necrosis demarcated by a thin rim of hepatitic reaction. In contrast, the portal tracts appeared almost normal. This histological appearance has not been associated with autoimmune hepatitis. This presentation and the histology may represent an early pattern of autoimmune injury to the liver.

Adult↗
PubMed1995

Selective tumorigenesis in non-parenchymal liver epithelial cell lines by hepatocyte growth factor transfection.

Hepatocyte growth factor (HGF) has been recently suggested to contribute to tumorigenesis by an autocrine mechanism in fibroblast cells overexpressing its receptor, the MET/HGFR protein. Since epithelial cells represent the primary physiologic target of HGF, we investigated whether inappropriate expression of HGF by epithelial cells which normally express MET/HGFR may also contribute to tumorigenesis. We have transfected a full length rat HGF gene into three mouse epithelial cell lines, one derived from breast (MM55) and two (BNL CL.2 and NMuLi) representing liver non-parenchymal epithelial cells (NPEC). We confirmed the presence of the transfected gene by Southern blot analysis, the production of HGF protein by immunofluorescence, and the preservation of HGF biologic activity by bio-assay. In comparison to untransfected cells, all three HGF-transfected cell lines displayed high level MET/HGFR autophosphorylation and increased ability to proliferate in media containing low serum. The two HGF-transfected liver NPEC lines, but not the HGF-transfected mammary cell line, displayed loss of cell contact growth-inhibition and acquired a markedly increased ability to form colonies in soft agar. Furthermore, the NPEC HGF-transfected cell lines formed much larger tumors in nude mice than the untransfected counterparts, with extensive invasion and sporadic lung metastases. These results demonstrate that overexpression of HGF in at least some epithelial cells contribute to tumorigenesis, and furthermore suggest a possible role for the HGF-MET/HGFR system in the progression of certain epithelial tumors.

Animals↗
PubMed1995

The use of granulocyte colony-stimulating factor after liver transplantation.

Granulocyte colony-stimulating factor (G-CSF) increases the number of circulating granulocytes and decreases TNF production while improving survival in sepsis models. To study the effects of G-CSF administration on sepsis and rejection, 37 primary liver allograft recipients received intravenous recombinant human G-CSF (rhG-CSF; 5-10 micrograms/kg/day) for the first 7-10 days following transplantation, targeting a blood absolute granulocyte count of between 10,000 and 20,000 cells/mm3. These recipients were monitored prospectively for sepsis and rejection, as were the previous 49 primary liver allograft recipients who did not receive G-CSF. Both groups utilized identical protocol immunosuppression and standardized diagnosis and treatment of sepsis and rejection. Univariate and logistic regression analysis of risk factors for sepsis and rejection revealed no difference between the two patient groups. G-CSF-treated patients developed an increased absolute granulocyte count over time (P < 0.0001, repeated-measures analysis of variance). G-CSF-treated patients had a decreased number of sepsis episodes per patient (0.92 +/- 1.5 vs. 2.18 +/- 2.8, P < 0.02, t test), and a lower percentage of sepsis-related deaths (8% vs. 22%, P < 0.04, chi-square test). The incidence of acute rejection was decreased in the G-CSF-treated group (22% vs. 51%, P < 0.01, chi-square test). These pilot data support further investigation into G-CSF's favorable effects on sepsis and rejection.

Analysis of Variance↗
PubMed1994

Leflunomide controls rejection in hamster to rat cardiac xenografts.

Leflunomide is an isoxazole derivative that has the ability to prevent acute rejection of cardiac, renal, and skin transplants in strongly rejecting rat models. Furthermore, leflunomide is able to interact synergistically with CsA to inhibit allograft rejection and also reverse ongoing allograft rejection. In vitro studies suggest that the mechanism of action of leflunomide is via an interruption of cytokine signaling in T cells. This study defines the ability of leflunomide to prevent and reverse rejection of concordant xenografts. One hundred nine adult Lewis rats in 13 groups received abdominal heterotopic cardiac transplants from Golden Syrian hamsters. The xenograft survived 3.9 +/-0.3 days without treatment. When leflunomide was given at 2.5, 5, 10, 15, or 20 mg/kg by gavage daily, the cardiac xenograft survivals were 5.0 +/- 0.6, 8.0 +/- 3.0, 52.0 +/- 20.2, 76.5 +/- 21.14, and 58.9 +/- 28.1 days, respectively. The survival rates were 4.0 +/- 0 and 27.7 +/- 28.7 days when CsA was given at 10 and 20 mg/kg i.m., respectively. The combination of CsA at 10 mg/kg with leflunomide at 10 mg/kg or 5 mg/kg prolonged cardiac xenograft survival to 106.0 +/- 50.2 days and > 90 days, respectively. There were no observable side effects in the latter combination. Histologic studies of untreated graft hearts 4 days after transplantation revealed infarction of myocardium and severe RBC extravasation. In contrast, the rejected hamster hearts from long-term survivors showed massive mononuclear cell infiltration and myocardium fibrosis in contrast to the early rejected picture. Therapy with leflunomide begun on day 2 reversed these rejection responses by day 6. In addition, the increase in allospecific IgM titers observed on day 2 was reversed, and the allospecific IgM to IgG isotype switch that occurred in untreated animals was prevented by leflunomide. These observations demonstrate that leflunomide, at nontoxic doses, effectively controlled acute rejection of concordant xenografts and synergistic immunosuppressive effect was achieved with leflunomide and CsA.

Animals↗