Safety and effectiveness of therapeutic magnetic resonance in diabetic foot ulcers: a prospective randomised controlled trial.

OBJECTIVE: To test the efficacy and safety of therapeutic magnetic resonance (TMR) in the management of diabetic foot ulcers (DFU), the authors designed a prospective randomised controlled trial in three highly specialised diabetic foot clinics. METHOD: All the patients consecutively visited in a period of 18 months were screened according to the inclusion (presence of an ulcer >1 cm2 in the foot lasting at least 6 weeks; ABPI>0.6; consent to participate in the study) and exclusion (Charcot's foot; local or systemic infections; chronic renal failure; any wearable electrically-driven life-supporting device) criteria. Patients, who were treated according to international guideline protocols, were randomised into two groups: group A received for four weeks the sham application of TMR, while group B received the active TMR for the same period. People were followed-up to 10 weeks and healing rate (HR), healing time (HT), rate of granulation tissue on wound bed (% GT), reduction of the area of the lesion (∆AL) and a score (0-3) evaluating erythema, oedema, pain and tenderness, respectively, were measured. Adverse events (AE) were registered and monitored throughout the study. RESULTS: No differences were observed in HR, HT and ∆AL between the two groups during follow-up, while % GT and the scores for erythema, oedema and pain at 10 weeks showed significant (p<0.05) improvements in group B compared with group A and versus baseline. When restricted to non-ischaemic patients (ABPI>0.8), ∆AL was significantly (p<0.05) more pronounced in group B than in group A. No difference in AE occurrence was observed between the two groups. CONCLUSION: Our study, despite not being able to demonstrate the effectiveness of TMR on healing rate at 10 weeks, with 4 weeks of active treatment in neuro-ischaemic DFUs, shows positive effects on clinical aspects of the DFU and is associated with a significant increase of GT in the wound bed. DECLARATION OF INTEREST: The study has been fully sponsored by Thereson S.p.A., manufacturer of TMR devices.

Massive isolation, morphological and functional characterization, and xenotransplantation of bovine pancreatic islets.

The limited availability of human donors makes the search for alternative islet sources mandatory for future developments in pancreatic islet transplantation. In this study, we report on the massive isolation of bovine islets of proven in vitro and in vivo viability. The islets were prepared by collagenase digestion, sequential filtrations, and density-gradient purification by modifying a technique previously developed in our laboratory for the porcine pancreas. The prepurification yield was 2,743 +/- 78 islet equivalents (IE)/g pancreas (mean +/- SE), with a postpurification recovery of 78.7 +/- 2.2%. Purity ranged from 80 to 90%. The histological and immunocytochemical studies demonstrated the identity and integrity of the islets with well-preserved insulin-, glucagon-, and somatostatin-containing cells. The morphological integrity of cultured bovine islets was demonstrated for up to 4 weeks from isolation. Insulin secretion from freshly isolated islets was similar at 3.3 mmol/l glucose (0.36 +/- 0.06 pmol.IE-1.min-1) and at 14 mmol/l glucose (0.42 +/- 0.00 pmol.IE-1.min-1), and it increased significantly (P < 0.01) at 25 mmol/l glucose (1.44 +/- 0.12 pmol.IE-1.min-1). Arginine, theophylline, and propionic acid increased insulin secretion from freshly isolated islets at 3.3 and 14 mmol/l glucose, but not at 25 mmol/l glucose. Islets cultured at 37 degrees C in CMRL 1066 culture medium for at least 10 days were shown to become responsive to a lower glucose concentration, as demonstrated by the significant increase of insulin release in response to 14 mmol/l glucose, when compared with basal secretion. This recovered responsivity to glucose was maintained after 4 weeks of culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful solitary pancreas transplantation with portal-enteric drainage following unsuccessful islet cell transplantation.

BACKGROUND: There are no data regarding the outcome of solitary pancreas transplantation (SPT) with portal venous drainage (PVD) following unsuccessful islet transplantation (ITx) after multiple islet injections into the portal vein. We herein describe the outcome of three SPTs with PVD performed after failed ITx. METHODS: Between October 2002 and December 2003, three SPTs with PVD were performed following unsuccessful ITx with multiple intraportal islet injections (mean 2.3 injections: range 2 to 3 injections) in two women and one man, aged 26, 49, and 60 years. Panel reactive antibody titer was 0% in all recipients. Immunosuppression was based on induction with either basiliximab (n = 2) or thymoglobulin (n = 1); maintenance therapy included steroids, mycophenolate mofetil, and tacrolimus. During the recipient operation, the absence of venous hypertension was established by direct measurement of portal pressure, before making the final decision to drain the pancreas into the portal vein. RESULTS: Portal pressures were 16 cm H2O, 14 cm H2O, and 13 cm H2O. Pancreas grafts were reperfused after a period of cold preservation of 638, 695, and 835 minutes, respectively. All grafts showed immediate endocrine function, maintaining their recipients insulin-independent for longest follow-ups of 8, 21, and 23 months, respectively. One recipient developed a nonocclusive venous thrombus that resolved with intravenous heparin infusion. CONCLUSIONS: Our experience showed that unsuccessful ITx with multiple intraportal injections does not necessarily preclude the possibility of subsequent successful SPT with PVD. Further experience is needed to define contraindications and possible complications of SPT with PVD following ITx.

Ninety-five percent insulin independence rate 3 years after pancreas transplantation alone with portal-enteric drainage.

AIMS: Portal-enteric drainage (PED) might be particularly suitable for pancreas transplantation alone (PTA), since it has been associated with an immunologic advantage and achieves excellent metabolic results. We describe our experience with a consecutive series of 40 PTAs with PED. METHODS: Between April 2001 and March 2004, 40 consecutive PTAs were performed with PED. Recipients were selected according to the American Diabetic Association recommendations. Donors were selected according to standard criteria irrespective of HLA match, although matching for A and B loci was considered at the time of graft allocation. Immunosuppression consisted of induction treatment with basiliximab (n = 34) or thymoglobulin (n = 6), and maintenance therapy with steroids, mycophenolate mofetil, and tacrolimus. RESULTS: After a mean cold ischemia time of 690 minutes (range, 517-965 min) all pancreases functioned immediately. Three grafts were lost due to hyperacute or accelerated rejection. No graft was lost to vascular thrombosis, although 5 (12.5%) nonocclusive thromboses were identified and the grafts were rescued with intravenous heparin infusion. A repeat laparotomy was required in 7 recipients (17.5%) No patient required multiple repeat laparotomies, and none died. After a mean follow-up of 16.4 months (range, 1-36 mo), 2 recipients were diagnosed with rejection episodes, which were reversed with steroid boluses. Actuarial 3-year patient, and graft survival rates were 100% and 94.9%, respectively. The following parameters showed significant improvement compared with pretransplantation evaluation: hemoglobin A1C concentration, total and high-density lipoprotein cholesterol levels, arterial blood pressure, cardiac performance, retinopathy, proteinuria, and neuropathy. CONCLUSIONS: Pancreas transplantation alone with PED provides high rates of long-term insulin-independence.

Neoral versus prograf in simultaneous pancreas-kidney transplantation with portal venous drainage: three-year results of a single-center, open-label, prospective, randomized pilot study.

BACKGROUND: The preferential use of tacrolimus (Prograf) over cyclosporine microemulsion (Neoral) in simultaneous pancreas-kidney transplantation (SPKTx) is mainly based on historical, retrospective studies. We herein report the 3-year results of a single-center, prospective, randomized comparison of the two calcineurin inhibitors in the setting of mycophenolate mofetil (MMF)-based immunosuppression and portal drainage of pancreas allografts. METHODS: Between May 2001 and August 2004, 47 SPKTx recipients who were stratified by recipient sex, were alternatively assigned to treatment with Neoral (n = 22) or Prograf (n = 25). Concurrent immunosuppression included induction treatment with basiliximab and maintenance with MMF and steroids. RESULTS: After a median follow-up of 24.0 months, all patients remained in the study arm into which they were initially enrolled. No pancreas rejection episode was observed. One acute kidney rejection was recorded in the Neoral arm (4.5%) as compared with 7 (28.0%) including one steroid-resistant episode, in the Prograf arm (P = .03). The cumulative incidence of adverse events was 31.8% (n = 7) in the Neoral arm compared with 92.0% (n = 23) in the Prograf arm (P < .0001). One patient died in each study arm. Patient, pancreas, and kidney survivals overlapped at 1- and 3-years posttransplant, namely all 95.4% for the Neoral arm compared with 95.8%, 91.8%, and 95.8%, respectively, for the Prograf arm (P > .05). CONCLUSIONS: We conclude that in MMF-based immunosuppression there is no convincing evidence that Prograf should be preferred to Neoral in SPKTx.

KPC-producing Klebsiella pneumoniae rectal colonization is a risk factor for mortality in patients with diabetic foot infections.

To evaluate the relationship between carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) gut colonization and mortality in diabetic patients with a foot infection (DFI) we performed a single-centre, retrospective, matched case-control study. In the study period, we identified 21 patients with DFI who had KPC-Kp gut colonization and 21 controls. The 90-day mortality rate was significantly higher in patients with colonized guts (47%) than the controls (4%) (p 0.013). A multivariate analysis demonstrated that gut colonization with KPC-Kp was the only independent predictor of mortality: odds ratio 13.33, 95% CI 1.90-272.80, p 0.024. In patients with DFI, KPC-Kp gut colonization appears to be an important risk factor for mortality.

Cryopreservation of purified bovine islets of Langerhans.

In this study, bovine islets were isolated by collagenase digestion and density gradient purification, equilibrated stepwise with 3 M dimethylsulfoxide at 24 degrees C, nucleated at -150 degrees C, slow cooled at 0.25 degrees C/min down to -40 degrees C, and finally stored at -150 degrees C. After variable periods of time, the islets were quickly thawed at 37 degrees C, and dimethylsulfoxide was removed by 0.75 M sucrose. Postthawing recovery was 86 +/- 6% islet equivalents. Histology confirmed the identity and morphological integrity of the islets. Insulin release from the frozen-thawed islets was 0.13 +/- 0.03 microU/is/min at 3.3 mmol/L glucose and increased significantly (0.27 +/- 0.04 microU/is/min, P < 0.05) at 25 mmol/L glucose. Encapsulated, cryopreserved islets reversed hyperglycemia in diabetic mice after 6-8 days following implantation. Therefore, the method described in this paper permitted successful cryopreservation of bovine islets of proven in vitro and in vivo viability.

Characterization of peripheral benzodiazepine receptors in purified large mammal pancreatic islets.

In this work, we evaluated the biochemical properties of peripheral benzodiazepine receptors (PBRs) in the porcine endocrine pancreas and their role in insulin release. Binding of [3H]1-(2-chlorophenyl-N-methyl-1-methyl-propyl)-3-isoquinolinecarboxa mide ([3H]PK-11195), a specific ligand of PBRs, to islet membranes was saturable and Scatchard's analysis of saturation curve demonstrated the presence of a single population of binding sites, with a dissociation constant (Kd) value of 4.75 +/- 0.70 nM and a maximum amount of specifically bound ligand (Bmax) of 4505 +/- 502 fmol/mg of proteins. The pharmacological profile of PBRs was determined as the ability of PK-11195 and several benzodiazepine compounds to displace [3H]PK-11195 from these binding sites. The rank order of potency yielded the following affinity results: PK-11195 > 7-chloro-1,3-dihydro-1-methyl-5-(p-chlorophenyl)-2H-1,4-benzodiazepine-2 -on (Ro 5-4864) > diazepam > or = flunitrazepam >> flumazenil. Secretion studies demonstrated that PK-11195 (1 and 10 microM) and Ro 5-4864 (10 and 50 microM) significantly potentiated insulin secretion from freshly isolated porcine islets at 3.3 mM glucose. This potentiating effect was not observed at 16.7 mM glucose concentration nor by the addition of clonazepam. These results show the presence of PBRs in purified porcine pancreatic islets and suggest an implication of PBRs in the mechanisms of insulin release.

The biguanide compound metformin prevents desensitization of human pancreatic islets induced by high glucose.

Pancreatic islet desensitization by high glucose concentrations is a temporary and reversible state of beta-cell refractoriness to glucose (and possibly other secretagogues), due to repeated or prolonged pre-exposure to increased glucose concentrations. We evaluated whether the oral antidiabetic agent metformin affects this phenomenon in isolated, human pancreatic islets, and whether the possible effects of the biguanide are influenced by the presence of a sulphonylurea, glyburide. Islets prepared from five human pancreases were incubated for 24 h in M199 culture medium containing either 5.5 or 22.2 mmol/l glucose, with or without a therapeutic concentration (2.4 microg/ml) of metformin. Then, the islets were challenged with either 3.3 mmol/l glucose, 16.7 mmol/l glucose, or 3.3 mmol/l glucose + 10 mmol/l arginine, and insulin release was measured. After incubation in the absence of metformin, the human islets exposed to 22.2 mmol/l glucose showed no significant increase in insulin release when challenged with 16.7 mmol/l glucose (confirming that hyperglycemia desensitizes pancreatic beta-cells). In the presence of metformin, the islets fully maintained the ability to significantly increase their insulin release in response to glucose, even when previously exposed to 22.2 mmol/l glucose. No major effect on arginine-induced insulin release was observed, whatever the culture conditions. The protective action of metformin was observed also when glyburide was present in the incubation medium, whereas the sulphonylurea alone did not affect insulin release from the islets previously exposed to high glucose concentrations. These in vitro results suggest that metformin can prevent the desensitization of human pancreatic islets induced by prolonged exposure to increased glucose concentrations.

Reducing insulin resistance with metformin: the evidence today.

Insulin resistance, defined as the inability of insulin to exert a normal biological action at the level of its target tissues, is one of the principal pathogenetic defects of type 2 diabetes. Metformin, the most widely-prescribed insulin-sensitizing agent in current clinical use, improves blood glucose control mainly by improving insulin-mediated suppression of hepatic glucose production, and by enhancing insulin-stimulated glucose disposal in skeletal muscle. Experimental studies show that metformin-mediated improvements in insulin sensitivity may be associated with several mechanisms, including increased insulin receptor tyrosine kinase activity, enhanced glycogen synthesis, and an increase in the recruitment and activity of GLUT4 glucose transporters. In adipose tissue, metformin promotes the re-esterification of free fatty acids and inhibits lipolysis, which may indirectly improve insulin sensitivity through reduced lipotoxicity. The improved glycaemia with metformin is not associated with increased circulating levels of insulin, and the risk of hypoglycaemia with metformin is minimal. The therapeutic profile of metformin supports its use for the control of blood glucose, in diabetic patients and for the prevention of diabetes in subjects with impaired glucose tolerance. Moreover, the improvement by metformin of cardiovascular risk factors associated with the dysmetabolic syndrome may account for the significant improvements in macrovascular outcomes observed in the UK Prospective Diabetes Study.

Lymphokine release during co-culture of human lympho-mononuclear cells and fresh or cultured human, porcine and bovine pancreatic islets.

In this study we evaluated whether isolated human (HI), porcine (PI) and bovine (BI) islets, either fresh (Fr) or cultured for 4 weeks (4 w) affect cytokine release from human lymphomononuclear cells (LMC) differently. We prepared LMC from peripheral blood by density gradient purification and co-cultured 1 x 10(6) LMC for 24 h with 100 hand-picked islets, either within 48 h of isolation or after culture for 4 weeks. Soluble interleukin-2 receptor (IL-2R), interferon-gamma (IFN), interleukin-4 (IL-4) and interleukin-10 (IL-10) were measured by sandwich enzyme-linked immunoadsorbent assay. Compared with controls (Ctrl, LMC without islets), Fr-HI, Fr-PI and Fr-BI caused a similar increase of IL-2R and IFN release, whereas 4 w-HI and 4 w-BI did not lead to any significant production of these two cytokines. IL-10 concentrations increased with Fr-PI and Fr-BI, but not with Fr-HI, and no major effect of the 4-week culture was seen. IL-4 levels were below the detection limit of the method used in these experiments. Thus, fresh allo- and xeno-islets caused a similar increase of the release of cytokines known to be markers of Th1 activation, whereas the release of IL-10, a marker of Th2 activation, increased with xeno-, but not with allo-islets; culturing the islets for 4 weeks decreased Th1, but not Th2 activation.

Long-term survival and function of isolated bovine pancreatic islets maintained in different culture media.

Bovine islets are being evaluated for their potential in transplantation studies. We studied the recovery, morphology, and function of purified bovine islets cultured up to 4 weeks under varying conditions. Approximately 60% of the initial islet mass could be recovered after 4 weeks at 37 degrees C in CMRL 1066 or M 199 culture medium, and the cultured islets were well preserved histologically and viable both in vitro and in vivo. On the other hand, culture with RPMI 1640 caused disaggregation of the islets within a few days, with altered in vitro viability. Thus, culturing purified bovine islets with appropriate media is a suitable procedure to maintain islet mass, morphology, and function in the long term.

Effects of glibenclamide and metformin (alone or in combination) on insulin release from isolated human pancreatic islets.

Isolated human pancreatic islets were prepared by collagenase digestion and density gradient purification, and the effects of glibenclamide (0.5 and 5.0 mumol/l) and metformin (20 and 200 mumol/l), alone or in combination, on insulin release were evaluated at varying glucose concentrations. At 3.3 mmol/l glucose level, the addition of 5.0 mumol/l glibenclamide or 5.0 mumol/l glibenclamide plus 200 mumol/l metformin caused a significant increase of insulin release, compared with glucose alone. At 16.7 mmol/l glucose concentration, a significant increase of insulin secretion, compared with glucose alone, was produced by the addition of either 5.0 mumol/l glibenclamide, 200 mumol/l metformin, or both 5.0 mumol/l glibenclamide and 200 mumol/l metformin. The effect of the combination of the two drugs was significantly higher than that with either drug used alone. Thus, glibenclamide was shown to have an insulinotropic effect on human islets at both low and high glucose concentrations, and metformin at high glucose concentrations. A possible synergistic effect of glibenclamide and metformin at high glucose concentrations is also suggested.

Echocardiographic evaluation in type 1 diabetic patients on waiting list for isolated pancreas or kidney-pancreas transplantation.

Type 1 diabetic patients may display abnormalities of left ventricular geometry and systolic and diastolic function. Patients on the waiting list for solitary pancreas or kidney-pancreas transplantation were evaluated by Doppler echocardiography to assess left ventricular geometry and systolic and diastolic function, and correlate these parameters with clinical characteristics. We evaluated 78 patients including 45 men with an overall mean age of 39.5 +/- 7.2 years and a disease duration of 24 +/- 9.8 years. Among these 78 patients, 13 showed isolated retinopathy, 9 isolated arterial hypertension, 45 concomitant retinopathy and hypertension and overt nephropathy, while 11 were free of complications. The results of our study showed an increased left ventricular mass and abnormal diastolic function among patients with simultaneous target organ complications and with hypertension, as has been reported in many previous studies. In contrast study patients with no complications showed normal left ventricular structure and function. This finding conflicts with data from several reports in the medical literature in which diastolic impairment was present in type 1 diabetic patients at an early stage of disease and with no evident microvascular and macrovascular complications.

Pancreas transplantation from marginal donors.

BACKGROUND: Marginal donor organs are a supplementary source of grafts that has not been fully exploited for pancreas transplantation (PTx). METHODS: A total of 100 PTx were performed with grafts procured from either 48 nonmarginal donors (NMD) or 52 marginal donors (MD), namely age greater than 45 years and/or severe hemodynamic instability at the time of procurement. PTx outcome was evaluated as the incidence of delayed endocrine pancreas function (DEPF), the complication rate, and the patient and graft survivals. RESULTS: The DEPF rate was 6.2% for NMD as compared to 0 for MD (P >.05). Relaparotomy rate was 12.5% for NMD and 9.6% for MD (P >.05). Actuarial 1-year graft survival was 91.7% and 94.2% for NMD and MD, respectively (P >.05). Equivalent figures for patients were 97.9% and 98.1%, respectively (P >.05). CONCLUSIONS: Pancreas from MD may be safely employed and significantly expand the donor pool for PTx.

Pancreas transplant alone.

Pancreas transplant alone (PTA) represents a growing proportion of overall pancreas transplantations, with 1-year patient and graft survivals of almost 100% and higher than 80%, respectively. PTA can restore normoglycemia without exogenous insulin administration and eliminate acute diabetic complications. In our series of 28 PTA, performed with portal-enteric drainage, 2-year patient and pancreas survivals were 100% and 87%, respectively. In patients with successful transplantation, rapid normalization of blood glucose level and HbA1c concentration was observed, due to restored endogenous insulin secretion. Several classical cardiovascular risk factors were measured before and after transplant, with significant improvements shortly after transplantation. Diabetic retinopathy improved in 58.8% of examined eyes, stabilized in 35.3%, and worsened in 5.9%. In conclusion, PTA represents a clinically relevant option for patients with type 1 diabetes without advanced renal disease. It restores normoglycemia in the vast majority of patients and seems to have a positive impact on late diabetic complications.

Retroperitoneal pancreas transplantation with portal-enteric drainage.

BACKGROUND: Portal-enteric drainage (PED) is the latest refinement in the surgical technique for pancreas transplantation (PTx). We herein describe the results of a modified technique for PED that places the pancreas in a totally retroperitoneal position. METHODS: Between April 2001 and June 2003, 79 PTx were performed using a retroperitoneal PED technique. RESULTS: No graft was lost due to surgical complications and the relaparotomy rate was 11.4%. Mean hospital stay averaged 25.9 days (+/-14.4 days) with a 30-day readmission rate of 12.7%. One graft was lost due to delayed (6 months) arterial thrombosis and three to acute rejection. The overall 1-year patient and graft survivals were 98.7% and 93.7%, respectively. CONCLUSIONS: Our data confirm that PED of pancreas grafts is associated with low morbidity and mortality rates. Whether retroperitoneal graft placement has actual advantages over the "classical" intraperitoneal position remains to be ascertained.

Portal enteric-drained solitary pancreas transplantation without surveillance biopsy: is it safe?

BACKGROUND: Most solitary pancreas transplants (SPTx) fail due to unrecognized rejection episodes. Consequently, SPTx are monitored by drainage into the bladder or by surveillance biopsies. METHODS: Between April 2001 and June 2003, a consecutive series of 48 SPTx were performed using portal enteric drainage (PED). Rejection episodes were diagnosed empirically, based on the elevated pancreatic enzymes without a surveillance biopsy. Immunosuppression consisted of basiliximab (n = 42) or ATG (n = 6), low-dose steroids, MMF, and tacrolimus. Donors (mean age 28.9 year; range 9 to 54 year) were selected according to standard criteria irrespective of HLA match, although the best HLA matching was considered at the time of graft allocation. RESULTS: After a mean cold ischemia time of 676 minutes (range 475 to 900 minutes), all but two pancreata (95.8%) functioned immediately. Relaparotomy was required in seven cases (14.6%). Three grafts were lost in the early posttransplant period due to hyperacute rejection. Two additional grafts were lost later due to arterial thrombosis or to chronic rejection. After a median follow-up period of 12.2 months (range 0.2 to 27 months) three further recipients were diagnosed with rejection episodes that were reversed with steroid boluses. Actuarial 1-year patient and graft survival rates were 100% and 93.1% and 2-year figures 100% and 88.7%, respectively. At the longest follow-up no recipient was diagnosed with a malignancy. CONCLUSIONS: With current immunosuppression protocols SPTx achieves high rates of insulin independence even without surveillance biopsy or routine use of T-cell-depleting therapies.

Solitary pancreas transplantation: preliminary findings about early reduction of proteinuria in incipient or evident diabetic type I nephropathy.

OBJECTIVE: Our work was aimed to evaluate the precocious reduction of proteinuria in patients suffering from diabetes mellitus type 1 with incipient and evident nephropathy after isolated pancreas transplantation (PTA). MATERIALS AND METHODS: From December 2000 to March 2003, we followed 24 PTA grafts in 24 patients with diabetes mellitus type 1 (mean age 37.8 years; mean duration of diabetes 24.8 years). The pancreas was transplanted with portal-enteric drainage in 23 patients and systemic-enteric in 1 patient. The immunosuppressive therapy used basilixmab induction and tacrolimus, mycophenolate mophetil (MMF), and low dose steroid maintenance therapy. The renal function, proteinuria, and the glucose metabolic parameters were evaluated before and during the following months after transplant. RESULTS: All patients are alive and twenty-one have a well-functioning pancreas with three grafts lost. All patients had persistence of normal renal function. Before transplantation 12 patients displayed proteinuria that was clearly reduced in 11 and gone in three patients, all of whom were insulin-independent. CONCLUSIONS: TPA seems to reduce, and in some cases to regress, the proteinuria associated with early diabetic nephropathy.