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F Saudek

Publications and source records attributed to F Saudek.

At least 19 recordsLinked to original sources
PubMed2005

Severe depletion of intraepidermal nerve fibers in skin biopsies of pancreas transplant recipients.

BACKGROUND: The minimally invasive method of skin biopsy with intraepidermal nerve fiber (IENF) counts may be used to analyze nerve regeneration in pancreas transplant (PTx) recipients. We assessed IENF counts as a database for long-term follow-up of diabetic neuropathy. METHODS: Skin biopsies were performed using a 3-mm punch from lower thigh and upper calf areas of 16 (13 pancreas/kidney, 3 pancreas alone) PTx patients (mean +/- SD: age, 45+/-8 years; type 1 diabetes duration, 27 +/- 8 years) at 1 month posttransplant. Ten healthy gender- and age-matched controls (C) were also examined. After fixation and freezing, 40-microm sections were stained using rabbit polyclonal antibody to the panaxonal marker PGP 9.5 followed by mouse antirabbit IgG antibody conjugated with rhodamine. Samples were imaged with a digital camera, mounted on a microscope, and equipped for fluorescence. The average number of IENF per millimeter length of epidermis was derived. Clinical neuropathy was assessed by foot vibration perception thresholds (VPT) with a biothesiometer (normal values < mean + 2 SD of C). RESULTS: Significantly lower IENF densities were found in skin biopsies from PTx (PTx vs C: thigh, 0.74 +/- 0.88 vs 9.74 +/- 2.41 IENF/mm; calf, 0.34 +/- 0.91 vs 7.66 +/- 3.16 IENF/mm; P < .001). IENF were totally absent from the thigh and calf samples of 7 and 12 PTxs, respectively. Clinical neuropathy (VPT > 21 V) was present in all but one PTx. CONCLUSIONS: Severe intraepidermal nerve fiber depletion is present in the lower limb area of pancreas transplant recipients with neuropathy. Long-term follow-up would probably be necessary to assess the possibility of posttransplant nerve fiber regeneration.

Adult↗
PubMed2005

Vitality of pancreatic islets labeled for magnetic resonance imaging with iron particles.

We previously described an in vivo method for pancreatic islet visualization using magnetic resonance imaging with the aid of superparamagnetic nanoparticles of iron oxide (Resovist) or by magnetic beads precoated with antibodies (Dynabeads). The aim of this study was to investigate the in vitro effect of islet labeling on their quality. Isolated rat islets were cultivated for 48 hours with a contrast agent or, in the case of magnetic antibody-coated beads, for only 2 hours. The ability to secrete insulin was tested by a static insulin release assay and the results were expressed as a stimulation index. Staining with propidium iodide and acridine orange was performed to determine the ratio of live to dead cells. Stimulation indices in the Resovist islets (n = 23) vs controls (n = 14) were 15.3 and 15.0, respectively, and in the Dynabeads islets (n = 15) vs controls (n = 12) 21.3 and 19.9, respectively. The vitality of the Resovist islets vs controls determined by live/dead cells ratio was 90.8% and 91.1%, respectively (n = 20), and in the Dynabeads islets vs controls was 89.4% and 91.8%, respectively (n = 11). Islet labeling with the contrast agent as well as with specific antibodies with iron beads did not change the vitality and insulin-secreting capacity assessed in vitro (P > .05). Magnetic resonance using iron nanoparticles represents the only method for in-vivo visualization of transplanted islets so far. Our data represent an important contribution for its clinical use.

Animals↗
PubMed2005

In vitro assessment of pancreatic islet vitality by oxymetry.

In order to assess the quality of freshly isolated and cultivated pancreatic islets designed for experimental transplantation in rats we combined the vitality staining test, in vitro measurement of insulin secretion capacity, and assessment of islet respiration. Oxygen consumption was measured using the respirometer Oxygraph 2K equipped with polarographic oxygen sensors. The results of oxymetry demonstrated a linear correlation between islet number and oxygen consumption. Respiration per unit of viable islet tissue was constant. Oxygen consumption tests were in good correlation with the results of insulin release assays, with a correlation coefficient of 0.82. We found no significant differences in all three vitality-testing methods performed with fresh and 24-hour cultivated islets (P > .05). We conclude that polarographic oxymetry provides a fast and easy evaluation test of islet quality. After appropriate standardization, the oxymetric technique can be used for routine clinical pretransplant islet quality testing. In addition, cell membrane integrity and mitochondrial function could be assessed after addition of specific respiration inhibitors or stimulators.

Animals↗
PubMed2005

Metabolic effect of sirolimus versus mycophenolate mofetil on pancreatic graft function in the early posttransplant period.

Metabolic effects of immunosuppressive agents are of great importance in pancreas or islet transplantation. The aim of our study was to compare effects of tacrolimus-based immunosuppression in conjunction with sirolimus (RAPA) versus mycophenolate mofetil (MMF) on glucose metabolism in type 1 diabetic recipients following a simultaneous pancreas and kidney transplantation (SPK). We examined 30 insulin-independent patients after SPK with venous systemic drainage of the pancreatic graft. All recipients had good kidney graft function. Fasting glycemia, insulin levels, glycosylated hemoglobin (HbA(lc)), standard intravenous glucose tolerance test (IVGTT), and trough RAPA levels were assessed in pancreas recipients before elective steroid withdrawal. Insulin sensitivity was evaluated using the homeostasis model assessment (HOMA-IR). The groups did not differ in age, BMI, posttransplant period, steroid daily dose, HbA(lc), and fasting glycemia. We did not find any significant difference in the IVGTT response. Area under the curve of insulin levels during IVGTT and HOMA-IR were significantly lower in the RAPA group. Trough levels of RAPA had no significant impact on any of the examined parameters. Glucose tolerance measured with the use of IVGTT was similar in patients treated with RAPA and MMF. However, recipients on sirolimus treatment had significantly lower insulinemia during the test and consequently more favorable indices of insulin action as assessed by HOMA-IR.

Area Under Curve↗
PubMed2005

Magnetic resonance imaging of intrahepatically transplanted islets using paramagnetic beads.

Superparamagnetic agents can be reliably used for magnetic resonance imaging (MRI) of pancreatic islets located in the liver sinusoids. However, the main disadvantages seemed to be the rather long culture time necessary for islet labeling and the low specificity of these agents. In the present study we investigated a more specific approach with a shorter labeling time using immunomagnetic particles. Isolated rat islets were cultivated with immunomagnetic beads coated with antibody against rat MHC class I antigen. Labeled islets were transplanted into the livers of syngeneic rats. The animals were examined weekly by MRI or livers explanted 10 minutes after islet transplantation for in vitro experiments. In both in vitro and in vivo studies, labeled transplanted islets were imaged as hypointensive spots, diffusely distributed throughout the liver. This experiment represents an alternative way of islet imaging by magnetic resonance, which is as effective as the use of known superparamagnetic contrast agents and more specific owing to targeting to specific donor antigens.

Animals↗
PubMed2004

Modulating amylase and lipase secretion in the pancreatic graft by somatostatin administration: preliminary results of a prospective, randomized trial.

Pancreas transplantation is a routine method for the treatment of diabetes mellitus. One of the main challenges of a transplant with extraperitoneal placement of the pancreatic graft is impaired wound healing due to massive amylase and lipase secretion by the pancreatic graft, evoking edemtous fluid. From February 2002 through January 2003, we performed pancreatic transplant procedures in 21 patients who were prospectively and randomly assigned to two groups: 8 organ donors and the recipients were administered somatostatin by continuous infusion. Thirteen grafts were harvested and transplanted without somatostatin infusion. The two groups did not show significantly differences in mean donor or recipient ages, weights, of serum amylase and lipase content values or drain output until day 6. There was a significantly lower lipase in the drain output of transplant recipients given somatostatin (12.5 and 54.2 micromol/L, respectively; P <.05). Neither the post-pancreatic transplant wound healing nor the number of rejection episodes were affected by somatostatin administration.

Amylases↗
PubMed2004

A prospective comparison of bladder versus enteric drainage in vascularized pancreas transplantation.

In previous years, the number of pancreas transplants has increased significantly. Debate continues over the optimum technique for exocrine drainage. Enteric drainage (ED) has recently been increasingly popular owing to the long-term complications of bladder drainage (BD). We prospectively evaluated 40 consecutive pancreas transplant recipients undergoing either bladder (n = 20) or enteric (n = 20) drainage. After simultaneous kidney-pancreas transplantation 1-year patient, kidney, and pancreas graft survival rates were 95%, 95%, 85% for the BD group, and 90%, 85%, 85%, for the ED group. Surgical complications were not significantly different between the two groups. The incidence of acute rejection, major infections and cytomegalovirus disease were also similar. The length of the initial hospital stay was likewise comparable. However, the BD group was characterized by a slight increase in the number of urologic complications, metabolic acidosis, and dehydration. Our results suggest excellent patient and graft survival irrespective of the drainage technique.

Adult↗
PubMed2004

A prospective comparison of bladder versus enteric drainage in vascularized pancreas transplantation.

Although the number of pancreas transplants has increased significantly in previous years, debate continues concerning the optimum technique for exocrine pancreas drainage. Enteric drainage (ED) has recently been increasingly popular due to the long-term complications with bladder drainage (BD). We prospectively assigned 40 consecutive pancreas transplant recipients to either bladder (n = 20) or enteric (n = 20) drainage. Patient, kidney, and pancreas graft survival rates at 1 year after simultaneous kidney-pancreas transplantation were 95%, 95%, 85%, for BD group and 90%, 85%, 85% for ED group, respectively. Surgical complications were not significantly different between the two groups. The incidence of acute rejection, major infections, and CMV disease were similar between groups. The length of the initial hospital stay was likewise comparable. However, the BD group showed a slight increase in the number of urologic complications, metabolic acidosis, and dehydration. Based on the results of our study, patient and graft survivals were excellent irrespective of technique.

Adult↗
PubMed2004

Enhancement of rat islet tolerance with bone marrow transplantation using a non-myeloablative procedure II: failure despite the presence of lymphocyte microchimerism in the fully allogeneic Lewis/Brown-Norway model.

Transplantation of donor bone marrow cells (BMTx) has been proven to be capable of including allogeneic transplant tolerance. In our previous experiments we reported the positive effect of BMTx together with short-term tacrolimus/hydrocortisone therapy on pancreatic islet survival in recipients haploidentical with donors. In this project we used the same transplant protocol to further investigate this effect in a fully mean histocompatibility system-mismatched model. Lewis male rats and Brown-Norway female rats were used as donors and recipients, respectively. Diabetic animals were treated according to four different protocols. Recipients in group I (n = 12) underwent islet transplantation (ITx) only. Group II (n = 12) and group III (n = 11) included animals treated for 52 days with tacrolimus (0.5 mg/kg) and hydrocortisone (2 mg/kg). Diabetes was induced by intravenously applied streptozocin (50 mg/kg). Seven days later islets were injected intrahepatically through the portal vein. In addition, rats in group III underwent BMTx on day 10. In group IV (n = 6) tacrolimus therapy, ITx and BMTx were used according to the previously published protocol of Ricordi et al. After more than 120 days, cumulative survival rates were 56% and 64% for recipients in groups II and III, respectively (p > 0.05). All animals in group I became hyperglycemic by day 11 following transplantation. Despite positive detection of lymphocyte microchimerism, we did not observe improved survival of allogeneic islets in animals treated with BMTx. Surprisingly, better islet survival was not found in group IV either (survival rate at 100 days: 33%). We conclude that demonstration of lymphocyte microchimerism, as detected by a sensitive polymerase chain reaction method, did not improve allogeneic islet survival in vivo and was not able to block mixed lymphocyte reaction in vitro. Whether a larger amount of transplanted hematopoietic cells could induce tolerance in this model remains to be evaluated.

Animals↗
PubMed2003

Genetic epidemiology of MODY in the Czech republic: new mutations in the MODY genes HNF-4alpha, GCK and HNF-1alpha.

AIMS/HYPOTHESIS: The aim of this study was to examine the prevalence and nature of mutations in HNF4alpha/MODY1, GCK/MODY2 and HNF-1alpha/MODY3 genes in Czech subjects with clinical diagnosis of MODY. METHODS: We studied 61 unrelated index probands of Czech origin (28 males, 33 females) with a clinical diagnosis of MODY and 202 family members. The mean age of probands was 22.7+/-12.0 years (range, 6-62) and the mean age at the first recognition of hyperglycaemia was 14.7+/-6.0 years (range, 1-25). The promotor and coding regions inclusive intron exon boundaries of the HNF-4alpha, GCK and HNF-1alpha genes were examined by PCR-dHPLC (HNF-1alpha and GCK) and direct sequencing. RESULTS: We identified 20 different mutations in the HNF-4alpha, GCK and HNF-1alpha in 29 families (48% of all families studied), giving a relative prevalence of 5% of MODY1, 31% of MODY2 and 11.5% of MODY3 among the Czech kindred with MODY. Three of 3, 10 of 11 and 1 of 6 of the mutations identified in HNF-4alpha, GCK and HNF-1alpha respectively, were new. CONCLUSION/INTERPRETATION: Of the families 48% carried mutations in the MODY1-3 genes and of the identified mutations 70% were new. In 52% of Czech families with clinical characteristics of MODY, no mutations were found in the analysed genes. This finding shows that the majority of MODY mutations in a central European population are local and that other MODY genes could be responsible for autosomal dominant transmission of diabetes mellitus.

Adolescent↗
PubMed2003

Spectral analysis of heart rate variation following simultaneous pancreas and kidney transplantation.

Only marginally improved results have been observed in standard autonomic function tests (AFT) in follow-up studies after simultaneous pancreas and kidney transplantation (SPK). We therefore used power spectral analysis (PSA) of heart rate variability (HRV) to assess the effect of SPK on autonomic neuropathy in patients with type I diabetes mellitus (DM I). We evaluated 82 patients with DM I who were insulin and dialysis free following SPK. Both pre- and posttransplant (at [mean +/- SD], 25 +/- 15 months post-SPK) examinations were performed in 29 patients. Posttransplant evolution was examined in another 60 patients with two serial examinations at 20 +/- 20 and 43 +/- 27 months after SPK. Comparisons included 32 age-matched healthy controls and 13 patients with kidney transplant alone (KTA) matched for age and duration of DM I at a comparable time point posttransplant. Short-term time (modified Ewing battery) and frequency domain (PSA of HRV: LF-low, HF-high frequency, and TP-total spectral power) analysis was performed with a telemetric, on-line, computer-aided system. Significantly worse results in all standard AFT and PSA indexes were obtained for SPK patients compared with controls at all time points. No significant improvement was seen in SPK patients in the posttransplant period and no differences were found compared with KTA patients. Thus the results of a power spectral analysis of HRV failed to show improvement following SPK. This examination adds little positive information to that obtained from standard autonomic function tests.

Adult↗
PubMed2003

[Vascular complications after pancreatic transplantation].

Transplantation of pancreas is presently the only way of treating diabetes of the 1st type, capable to secure a long-term normoglycemia. In spite of the fact that the surgical technique and tactics of the whole intervention has been standardized over the last years, surgical complications and more specifically vascular complications still pose a certain risk of the graft loss. The thrombosis of vessels of the transplanted pancreas occurred in our group in 4.1 per cent of cases. The other rare complications included a false aneurysm of the supplying artery and stenosis of the out-coming vein from the pancreatic graft. Both these complications were successfully treated by a radio-invasive approach. A refinement of the surgical technique and the introduction of new immunosuppressive drugs manifests favorably in decreasing occurrence of vascular complications after the transplantation of pancreas.

Adult↗
PubMed2003

[Gene therapy in the treatment of diabetes mellitus].

Multiple genetic factors are involved in the pathogenesis of type 1 and 2 diabetes mellitus. A defect, which could be ascribed to a single or only few genes, has not been established yet. An exception represents the Maturity Onset Diabetes of the Young (MODY) which is rather rare and is caused by mutations in some of 6 known genes. Principles of gene therapy focus mainly on generation of replenishable sources of insulin producing tissue. Which could be used for replacement of the destroyed or failing beta-cells. Current approaches include stimulation of embryonic or adult stem cell proliferation and differentiation into beta-cells, beta-cell proliferation, transdifferentiation of non-islet cells into glucose-sensitive insulin-producing cells and xenotransplantation. Genetic modification is being studied to prevent islet rejection (e.g. local expression of immuno-suppressive cytokines or ligands inducing T-cell apoptosis, knock-out of specific animal genes or transfer of human genes into animal tissue donors) or to construct "superislets" resistant to apoptosis or oxidative stress. For prevention of type 1 diabetes and perhaps for induction of specific immune tolerance vaccination with DNA fragments encoding for specific auto or alloantigens represents a promising approach. In addition, gene therapy offers some hope for the future treatment of diabetic vascular complication, neuropathy and syndromes of insulin resistance.

Diabetes Mellitus↗
PubMed2001

[Pancreas transplantation: who and when?].

Hyperglycemia is an important factor in the development and progression of the complications of diabetes. Pancreas transplantation is currently the only method able to achieve sustained normoglycemia in type I diabetes. By now, this procedure has become an accepted treatment option combined with kidney transplantation for selected patients with end-stage diabetic nephropathy. The definite benefits of pancreas transplantation comprise relieve from insulin administration, superb glycemic control, improved quality of life and long-term survival of patient with severe autonomic neuropathy. Presumed benefits represent stabilization or slowing of progression of microvascular complications. Definite disadvantages are the risk of the surgical procedure, graft rejection and the necessity of permanent immunosuppression. Isolated pancreas transplantation in nonuremic type-1 diabetic patients is still controversial. Diabetic complications of the potential recipient have to be potentially correctable by the transplantation and their significance must exceed all risks of the operation and life-long immunosuppression. Currently, approx. 25 combined transplants are performed per year in IKEM with the results comparable to those reported by the International Pancreas Transplant Registry. Seven nonuremic type-1 diabetic recipients of 8 operated in IKEM by June 2000 have been insulin-independent for 1-33 months. The main indication for isolated pancreas transplantation is brittle diabetes with hypoglycemia unawareness syndrome and labile diabetes with severe autonomic neuropathy and rapid progression of microangiopathy despite appropriate intensified insulin therapy.

Blood Glucose↗
PubMed2001

Deltins: immunochemical evidence for a novel population of peptides of the D cells of the gastro-entero-pancreatic endocrine system.

Differences between the immunocytochemical behaviour of antisera to partially purified porcine gastrins and antisera to either synthetic human gastrin-17-I or highly purified porcine gastrin-17-I raised the hypothesis that hog antral gastrin extracts contain peptides different from somatostatin and gastrin that are responsible for the immunocytochemical reaction of the former antisera in the D (delta) cells of the gastro-entero-pancreatic (GEP) endocrine system. This study was performed to prove this hypothesis. A discard fraction obtained after gel filtration of hog antral gastrin extracts on Sephadex G-50 Superfine was employed to immunize five rabbits. The discard fraction is highly heterogeneous on two-dimensional electrophoresis and contains merely traces of somatostatin and gastrin in RIA. However, rabbit antisera to the discard fraction give strongly positive immunocytochemical reactions exclusively in the D cells of the human antroduodenal mucosa and of the pancreatic islets. Absorption of the antisera with the lyophilized discard fraction abolishes the staining of the D cells, whereas absorption of the antisera with several somatostatins does not affect the staining. Vice versa, staining of the D cells with antisera to cyclic somatostatin-14 is abolished by absorption of the antisera with somatostatin-14 but not by absorption with excess of the discard fraction. In RIA, antisera to the discard fraction do not bind radiolabelled (Tyr(1))-somatostatin-14, Tyr-somatostatin-28 or synthetic human gastrin-17-I. Two-dimensional electrophoresis of acid extracts of isolated canine pancreatic islets followed by Western blotting shows different patterns of distribution of immunoreactive spots obtained with antisera to the discard fraction, to somatostatin-14, and to human proinsulin respectively. These results indicate the existence of a novel population of peptides of the D cells of the GEP endocrine system, for which we propose the term deltins.

Animals↗
PubMed2001

100 pancreas transplantations with extraperitoneal graft placement.

The authors present the results of 100 pancreatico-duodenal grafts placed extraperitoneally with the bladder drainage. The onset of pancreatic graft function was immediate in all cases and the patients became insulin free. Despite the extraperitoneal graft placement the incidence of surgical complications was low. The only exception was slightly impaired wound healing. The Authors claim that this surgical technique allows the elimination of intraperitoneal infection and easy performance of the graft biopsy.

Duodenum↗