PubMed Health⌕ Search

Biomedical subjects

K H Tscheliessnigg

Publications and source records attributed to K H Tscheliessnigg.

At least 19 recordsLinked to original sources

Morphological and functional characterization of a pancreatic beta-cell line microencapsulated in sodium cellulose sulfate/poly(diallyldimethylammonium chloride).

BACKGROUND: Late diabetic complications cannot be prevented totally by current antidiabetic strategies. Therefore, new therapeutic concepts of insulin replacement such as pancreas transplantation are evolving. Due to the shortage of human donor organs, transplantation of microencapsulated xenogeneic pancreatic islet cells has attracted considerable attention. Sodium cellulose sulfate/poly(diallyldimethylammonium chloride) (NaCS/PDADMAC) is a material with favorable biogenic properties that has been used for microencapsulation of various cell types. However, there are no data on the suitability of NaCS/PDADMAC for microencapsulation of pancreatic beta-cells. MATERIAL AND METHODS: Cell growth and viability of NaCS/PDADMAC-microencapsulated HIT-T15 cells, an immortalized hamster pancreatic beta-cell line, were assessed using a dimethylthiazol-diphenyltetrazoliumbromide (MTT)-based cell growth determination kit and apoptosis was detected by antibodies against activated caspase 3. Glucose-dependent insulin secretion was assessed with ELISA and the uptake of glucose was measured using fluorescence-labeled glucose. RESULTS: Statistical analysis revealed no differences in glucose-dependent cell proliferation, insulin secretion and glucose uptake between non-microencapsulated and microencapsulated HIT-T15 cells. Stimulation of HIT-T15 cells with glucose (100 mg/ml) resulted in a biphasic insulin secretion response. CONCLUSION: Microencapsulation of HIT-T15 cells in NaCS/PDADMAC does not influence cell proliferation, insulin secretion and glucose uptake. Our results indicate that NaCS/PDADMAC is well suited for microencapsulation of pancreatic beta-cells.

Animals↗

Nonnephrotoxic immunosuppression in patients after liver transplantation.

INTRODUCTION: Calcineurin inhibitor (CI)-associated renal impairment and renal failure after liver transplantation has been recognized since the early days of its use. Various strategies have been used to prevent or slow down the progression of renal dysfunction in liver transplant recipients, but did not succeed. In this report, we describe the course of renal function of 58 stable liver transplant recipients and compared 2 groups with different immunosuppressive protocols. METHODS: In the study group, 22 patients at various intervals from liver transplantation were included. The immunosuppressive therapy consisted of Sirolimus (SRL). Additional all patients except 2 received Mycophenolate Mofetil (MMF) and 14 of them also received Tacrolimus. Patients of the control group (36 patients) had an immunosuppressive therapy with calcineurin inhibitors. Patients were monitored for creatinine monthly and creatinine clearance (CCr) every sixth month. Risk factors for renal dysfunction were evaluated. RESULTS: After introduction of SRL in patients with renal impairment and after a mean follow-up time of 12 (2-26) months, there was a decrease of 28.3% in mean creatinine and of 41.8% in mean urea. We observed an improvement of renal function in all patients initially after introduction of SRL. In the control group, in comparison to preoperative levels, there was an increase of 27.5% in mean creatinine and of 13.3% in mean urea after a mean follow-up time of 3.6 years with CI therapy. CONCLUSION: The results of our retrospective study showed that with SRL renal impairment could be stopped and renal function could be improved. We suggest administering immunosuppressive therapy with SRL in combination with low dose Tacrolimus and/or MMF for patients with renal impairment.

Adult↗

Center experience in liver transplantation (LTX): management of dermal side effects caused by sirolimus.

INTRODUCTION: Sirolimus improves post transplant maintenance therapy in LTX. Dermal side effects causing pain and discomfort can limit patients' compliance. The package insert mentions such skin disorders as acne and rash. One case of sirolimus-induced leucocytoclastic vasculitis is reported in the literature. METHODS: From July 1998 to October 2003, Sirolimus was implemented in the immunosuppressive protocol in 23 out of 60 liver recipients. Sirolimus target levels are between 3 and <10 ng/dl. Combination with a calcineurinblocker and/or MMF (mycophenolate mofetil) depending on liver function and creatinine is standard. Weekly patient monitoring in the first month after discharge included physical examination, blood samples and immunosuppresant trough levels. Biopsies were taken from untypical efflorescences. RESULTS: Three patients with non-specific effloresces were reported: one with leucocytoclastic vasculitis and one with exfoliate forearm dermatitis required change of medication while one perivascular lymphocytic eosinophilic dermatitis subsided after dose reduction. In three cases of mouth ulcer, trough levels exceeded 10 ng/dl and in six patients acne diminished after dose reduction. Eighteen out of 23 patients are still receiving sirolimus. Reasons for removal from the study were incompliance and incompatibility. Two patients died. DISCUSSION: Immunosuppressants inevitably produce side effects in TX recipients. The positive management of troublesome side effects contributes importantly to compliance and patient survival.

Acne Vulgaris↗

Late acute cardiac allograft rejection: new therapeutic options?

BACKGROUND: Late acute cellular rejection is associated with decreased survival and the development of CAV. Among new immunosuppressive drugs introduced into clinical practice, everolimus, has been shown to be safe in cardiac transplantation. We report our experience with everolimus in heart transplant recipients who developed late acute cellular cardiac rejection. METHODS: Patients with a history of previous rejection episodes who experienced cardiac rejection were switched to an everolimus, cyclosporine, and steroid immunosuppressive regimen. All patients had already received statins and antihypertensive medications. Everolimus, cyclosporine trough levels, and laboratory values were controlled monthly. Drug administration was adapted to an everolimus trough level between 3 and 8 ng/mL, mean maintenance dosage was 0.25 to 1.5 mg twice a day. Death, safety, side effects, biopsy-proven acute rejection episodes, laboratory values, and blood levels were evaluated retrospectively. RESULTS: Four cardiac allograft recipients (two male, two female), at a median of 1473.25 days post-orthotopic heart transplantation (oHTx) (range = 65 to 3045), received 1 to 1.5 mg everolimus per day. Over a follow-up period of at least 2 month (range = 2 to 10) the mortality was 0%. The drug was well tolerated; no acute cellular rejection greater than grade 1a (ISHLT grading) was observed after 2 months. In one patient increased cholesterol values and in two others, elevated triglyceride levels were seen, but were controlled with increased statin therapy. No obvious increased creatinine values were seen with everolimus. CONCLUSION: In conclusion, conversion to an everolimus-based immunosuppressive regimen after late cardiac rejection is safe and effective; no major side effects were observed.

Acute Disease↗

Improving the rate of organ donation.

BACKGROUND: Organ shortage is a major problem in transplantation. Many potential donors are still lost due to a lack of information and communication. Many transplantation centers report a major donor increase after introducing new donor policies. The aim of this study was to evaluate in retrospective fashion a new donor policy in our region. METHODS: For the past 10 years all reported donors from intensive care units (ICUs) in our region were evaluated. Our new policy had 2 main steps: accepting more marginal grafts and using a transplantation representative. The goal was the improved communication with ICUs to support physicians involved in donor care. A public information program was also implemented. RESULTS: In the first year, numbers of donors obviously improved (+60.5%) and remained stable the following year. The mean donor age increased to 41.56 years. The donor pool showed mainly an improved kidney-donation rate (+53%) with also an increase in multiorgan donation (+37%). One year posttransplantation survival was not negatively influenced by this donor pool. As expected, transplantation activities increased notably, particularly liver transplantation (+31.11%) but also kidney transplantation (+26.73%). DISCUSSION: Many donors are lost because physicians in charge of brain dead patients are not fully informed about modified donation criteria. The reason for this is a lack of information and communication by transplantation units. Improved surgical techniques and better preoperative, intraoperative, and postoperative treatment have yielded better results with marginal grafts. Immediate graft function in recipients of suboptimal grafts may be delayed, but without a significantly negative impact on patient and graft survival. Because the age of organ recipients is steadily increasing with fewer contraindications for transplants, more organs will be needed.

Brain Death↗

Serum osteoprotegerin is a major determinant of bone density development and prevalent vertebral fracture status following cardiac transplantation.

Osteoprotegerin (OPG) is an antiresorptive cytokine and a key regulator of osteoclastogenesis and activity. Since OPG is downregulated by glucocorticoids and cyclosporine A in vitro we examined whether immunosuppressive therapy would play a role in the development of transplantation osteoporosis. We enrolled 57 cardiac transplant recipients (median time since transplantation, 3.2 years (1.1-11.5 years)) in this cross-sectional study. Standardized spinal X-rays as well as hip bone density measurements were performed in all patients. Serum OPG was determined using a commercially available ELISA. Vertebral fractures were present in 56% of the patients. Bone densities of all femoral neck subregions were correlated to serum OPG concentrations (r values between 0.40 and 0.48, all P < 0.005). Multiple regression analysis revealed OPG levels to be independently correlated to femoral neck Z scores (r = 0.49, P = 0.002). After adjustment for age, BMI, neck Z score, renal function, and months since transplantation, serum OPG was the only significant predictor of prevalent vertebral fractures (P = 0.001). In a separate 6-month prospective study of 14 heart transplant recipients receiving calcium and vitamin D serum OPG levels fell by 41% (P = 0.0004) after 3 months and 47% (P = 0.0001) after 6 months following cardiac transplantation. Bone loss at the lumbar spine and femoral neck after 6 months was correlated to the decrease in serum OPG at 6 months (r = 0.82, P < 0.0001, and r = 0.60, P = 0.02, respectively) as well as 3 months after cardiac transplantation (r = 0.65, P = 0.01, and r = 0.69, P = 0.006, respectively). Serum OPG alone accounted for 67% of the variance of lumbar spine bone density changes over the first 6 months posttransplantation. We conclude that serum OPG levels decline consistently in all patients following initiation of immunosuppressive therapy and are independently correlated with changes in bone density. We hypothesize that OPG plays a major role in the development of transplantation osteoporosis.

Aged↗

Occurance of apoptosis during ischemia in porcine pancreas islet cells.

PURPOSE: Pancreas islet transplantation is a potential treatment of diabetes mellitus and porcine organs provide an easily available source of cells. Unfortunately quality and quantity of isolated islets are still not satisfactory. Apoptosis occurs in freshly isolated islets and plays a significant role in early graft loss. We evaluated the influence of four storage solutions on porcine pancreas islets. METHOD: After warm ischemia of 15-20 minutes 12 organs were stored in 4 cold preservation solutions: Histidine-Tryptophan-Ketoglutarate solution (HTK), Hank's buffered saline solution (HBSS), University of Wisconsin (UW) solution and Ringer-Lactate (R). After cold ischemia for 100 minutes, organs were fixed in 3% formalin. Apoptotic cells were counted on hematocylin-eosin stainings. RESULTS: Most apoptotic cells were found in organs stored in R. Low numbers were found in the other groups. The difference between organs stored in R and organs stored in UW, HTK, or HBSS was highly significant. No significant difference could be found between UW, HTK and HBSS. CONCLUSION: Cold and warm ischemia of the pancreas seems to induce apoptosis in islet cells. Preservation solutions cause less apoptosis than electrolyte solution. No significant differences could be found among the preservation solutions.

Animals↗

Correlation between changes in stroke volume and the paced intracardiac electrogram.

AIM: The aim of this study was to examine the relation between cardiac haemodynamics and parameters extracted from the intracardiac electrogram obtained during pacing, i.e. ventricular evoked response. METHODS AND RESULTS: In the course of routinely scheduled right heart catheterization, intracardiac electrograms and cardiac haemodynamics were monitored simultaneously in ten heart transplant patients (two females, aged 48 +/- 12 (18-59) years), using pacemaker telemetry and Swan-Ganz thermodilution techniques. Different haemodynamic states were induced by pacemaker programming (pacing rate changes) and table tilting (postural changes). Forty different haemodynamic states were assessed, with an average of three (2.4) haemodynamic variations in each patient. Linear regression analysis between relative stroke volume changes and relative changes in the R wave slew rate as extracted from the evoked responses revealed a strong, inverse, and highly significant correlation (r= - 0.93, P<0.0001) between those parameters. Similar results were obtained for pacing rate and postural variations alone, respectively. CONCLUSIONS: The strong correlation between changes in stroke volume and R slew rate indicates that paced intracardiac electrograms reflect changes in the size and geometry of the heart. Telemetrically recorded intracardiac electrograms may thus be used non-invasively to assess key aspects of cardiac haemodynamics.

Adolescent↗

Characteristics and clinical relevance of chronic anemia in adult heart transplant recipients.

BACKGROUND: Mild chronic anemia following heart transplantation (HTX), with hemoglobin (Hb) values of 10-14 g/dL in men and 10-12 g/dL in women, is frequent. It has continued to be of uncertain etiology yet clinical relevance. Nonetheless, therapeutic immunosuppression has been regarded as a major cause of chronic anemia in HTX patients. METHODS: Sixty outpatients were observed over a period of 5 yr after HTX. Laboratory values related to anemia such as Hb, erythropoietin (EPO), ferritin, transferrin, iron, and vitamin levels were obtained and analyzed monthly. Patients were divided into two groups retrospectively. Patients with persistent anemia for more than 1 yr were compared with non-anemic patients. RESULTS: Forty-three (72%) of the 60 patients were anemic. Anemia was normochromic, normocytic, and slightly anisocytic. Anemic and non-anemic patients showed EPO levels within the expected range as defined by Erslev (Erythropoietin. N Engl J Med 1991: 324: 1339). Reticulocyte counts were found to be normal in all patients. Iron deficiency and deficiency of vitamin B12 or folic acid were not observed. Patients with persistent anemia showed a significantly shorter survival period than non-anemic patients (p<0.02). CONCLUSIONS: Mild anemia following HTX shows the same characteristics as anemia in chronic diseases. Persisting mild anemia used to be associated with a shorter life expectancy. There is no evidence that standard immunosuppression causes anemia.

Anemia↗

Segmental degradation of left ventricular wall motion after persistent coronary fistula in a posttransplantation patient: a case report and short review of literature.

A 50-year-old man received an orthotopic heart transplant because of severe coronary heart disease and congestive heart failure. Two years after the transplantation, a continuous murmur occurred at the left sternal edge after repeated endomyocardial biopsies. Echocardiography and coronary angiography revealed a dilated left anterior descending artery with a fistula to the right ventricle. The circumflex was large with an equally postero-lateral branch, and the right coronary artery was rather small with collaterals to the distal part of the left anterior descending branch. The patient had refused any intervention to close the fistula. The left ventricular levogram was normal. Two years later, in a follow-up angiogram, the left ventricular ejection fraction had decreased as a result of hypo- and akinesis of the apex and posterior wall. We suggest that this local wall motion disturbance derives from a steal phenomenon rather than being a sequela of rejection. The decrease in left ventricular ejection fraction was associated with shortness of breath upon moderate exercise. Standard heart failure medication relieved the patient's symptoms. The observation of local wall motion disturbances in this case, as well as conflicting views in the literature, raises the question whether postbiopsy coronary fistulas in transplant patients should be closed.

Angiotensin-Converting Enzyme Inhibitors↗

Non-invasive graft monitoring after heart transplantation: rationale to reduce the number of endomyocardial biopsies.

The endomyocardial biopsy is invasive, reduces quality of life and cannot be repeated daily. Initial studies on noninvasive cardiac graft monitoring have been presented recently. During the heart transplant procedure, we implanted wideband telemetric pacemakers and fractally coated, epimyocardial electrodes. On biopsy days and during each follow-up, intramyocardial electrogram sequences were obtained. The maximum T-slew rate from the ventricular evoked response (VER) was automatically calculated and compared to the biopsy results (n = 331, ISHLT grading). The VER T-slew rate was significantly lower during rejection grade 2 or higher. The negative predictive value to exclude rejection was 98%. Using a single threshold diagnosis model, 74% of the biopsies could have been avoided. Noninvasive cardiac graft monitoring can reduce the need for surveillance biopsies and may offer a tool to optimize immunosuppressive therapy after heart transplantation.

Adolescent↗

Noninvasive measurement of pulmonary vascular resistances by assessment of cardiac output and pulmonary transit time.

RATIONALE AND OBJECTIVES: Pulmonary vascular resistance is of special interest in many diseases. Usually it is determined invasively by catheterization, but cardiac output and pulmonary transit time can be ascertained by several noninvasive methods. METHODS: Fourteen heart recipients (age 34-71 years) were examined by electron-beam CT of the heart. Cine and flow studies were performed using a total of 60 mL of contrast and a breath-hold of 20 seconds. RESULTS: A mathematical model for calculating pulmonary vascular resistances from noninvasively measured cardiac outputs and pulmonary transit times was developed. Right-sided heart catheterization served as the reference method. CONCLUSIONS: The formula created seems to allow a clinically valid estimate of pulmonary vascular resistance from noninvasively acquired data.

Algorithms↗

Mild chronic anemia following heart transplantation: a syndrome with prognostic relevance?

The clinical relevance of mild chronic anemia in patients after heart transplantation (HTX) has not yet been demonstrated. Forty-five outpatients who had undergone HTX 2-99 months prior to investigation and who had not received blood transfusions or erythropoietin (EPO) before data acquisition were observed over a period of 37 months. Anemia was found in 36 of the 45 patients and was normocytic, normochromic, and slightly anisocytotic (coefficient of variation = 16 +/- 2, normal 11.5-14.5). Anemic patients showed elevated EPO levels, whereas in nonanemic patients EPO levels were normal. Survival after HTX differed significantly in anemic and nonanemic patients (P < 0.02), with 100% survival in the nonanemic and 85% in the anemic group. Chronic anemia in patients after HTX shows a typical pattern. Even when mild, anemia in patients after HTX seems to be of prognostic value and thus might be an indicator of chronic disorders.

Adolescent↗