Conservative surgical approach versus non-surgical management for diabetic neuropathic foot ulcers: a randomized trial.

To test the efficacy of surgical treatment of non-infected neuropathic foot ulcers compared to conventional non-surgical management, a group of diabetic outpatients attending our diabetic foot clinic were studied. All patients who came to the clinic for the first time from January to December 1995 inclusive with an uncomplicated neuropathic ulcer were randomized into two groups. Group A received conservative treatment, consisting of relief of weight-bearing, regular dressings; group B underwent surgical excision, eventual debridement or removal of bone segments underlying the lesion and surgical closure. Healing rate, healing time, prevalence of infection, relapse during a 6-month period following intervention and subjective discomfort were assessed. Twenty-four ulcers in 21 patients were treated in group A (17 Type 2 DM/3 Type 1 DM, age 63.24 +/- 13.46 yr, duration of diabetes 18.2 +/- 8.41 yr, HbA1c 9.5 +/- 3.8%) and 22 ulcers in 21 patients in group B (19 Type 2 DM/2 Type 1 DM, age 65.53 +/- 9.87yr, duration of diabetes 16.84 +/- 10.61 yr; HbA1c 8.9 +/- 2.2%). Healing rate was lower (79.2% = 19/24 ulcers) in group A than in group B (95.5% = 21/22 ulcers; p < 0.05), and healing time was longer (128.9 +/- 86.60 days vs 46.73 +/- 38.94 days; p < 0.001). Infective complications occurred significantly more often in group A patients (3/24, 12.5% vs 1/22, 4.5%; p < 0.05), as did relapses of ulcerations (8 vs 3; p < 0.01). There were only two minor perioperative complications in group B patients. Patients reported a higher degree of satisfaction in group B (p < 0.01) as well as lower discomfort (p < 0.05) and restrictions (p < 0.05). Thus surgical treatment of neuropathic foot ulcers in diabetic patients proved to be an effective approach compared to conventional treatment in terms of healing time, complications, and relapses, and can be safely performed in an outpatient setting.

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.

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.