In diabetic patients, mycotic infections may increase the risk of developing diabetic foot syndrome. However, little data are available on the prevalence of fungal foot infections in patients with diabetes. In a first study published using data obtained during a conference attended by patients with long-term diabetes mellitus type 1 (DM1), 78/95 patients (82.1%) showed probable pedal fungal infections, of which 84.6% (66/78) were mycologically confirmed by direct microscopy and/or culture. The dermatophyte Trichophyton rubrum was the most common (69.2% of isolates). Significant correlation was found between infection and the gender (men more frequently affected) and the age of the patients. Marked mycoses on the soles of the feet were often considered to be dry skin by the patients. In a second study, 174 [31 DM1, 112 DM2 and 29 healthy accompanying persons (HAP), family members without DM] participants at a regional patients' symposium on diabetes took part in an examination for fungal infections and neuropathy of the feet. In addition to the items of the first study, we gathered data on the quality of blood glucose control (HbA1c), peripheral neuropathy (neuropathy symptome and deficit score) and measurement of sudomotoric activity by Neuropad. Mean duration of disease was 23.6 (DM1) and 11.2 (DM2) years, mean HbA1c 7.56% (DM1) and 6.89% (DM2) and fungal foot infections were confirmed at 35.5% (DM1), 53.1% (DM2) and 37.9% (HAP) respectively. In DM2, the prevalence of positive fungal samples is significantly higher for participants with less controlled blood glucose (higher HbA1c) (P = 0.04). Mycotic foot infection is also correlated with age, gender and duration of diabetes disease. Of special interest is the finding of relatively high numbers of black fungi ('Dematiaceae') (n = 10), Phialophora europea (n = 3) being the most common one. The sudomotoric activity was impaired in a very high number of participants [107/171 (61.5%)], and was found positively correlated with the prevalence of fungal foot infection in DM2 but not in DM1 and HAP. The high prevalence of fungal infections detected in DM1 as well as in DM2 diabetics is remarkable, especially considering this highly motivated collective. Therefore, it appears that the feet of diabetics require more diagnostic, therapeutic and preventive care in terms of mycotic infections and sudomotoric dysfunction than previously thought.

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Aims/hypothesis. The ATP-regulated potassium (K ATP ) channel in the pancreatic beta cell couples the metabolic state to electrical activity. The primary regulator of the K ATP channel is generally accepted to be changes in ATP/ADP ratio, where ATP inhibits and ADP activates channel activity. Recently, we showed that long-chain CoA (LC-CoA) esters form a new class of potent K ATP channel activators in rodents, as studied in inside-out patches. Methods. In this study we have investigated the effects of LC-CoA esters in human pancreatic beta cells using the inside-out and whole-cell configurations of the patch clamp technique. Results. Human K ATP channels were potently activated by acyl-CoA esters with a chain length exceeding 12 carbons. Activation by LC-CoA esters did not require the presence of Mg 2+ or adenine nucleotides. A detailed characterization of the concentration-dependent relationship showed an EC 50 of 0.7±0.1 µmol/l. Furthermore, in the presence of an ATP/ADP ratio of 10 (1.1 mmol/l total adenine nucleotides), whole-cell K ATP channel currents increased approximately sixfold following addition of 1 µmol/l LC-CoA ester. The presence of 1 µmol/l LC-CoA in the recording pipette solution increased beta-cell input conductance, from 0.5±0.2 nS to 2.5±1.3 nS. Conclusion/interpretation. Taken together, these results show that LC-CoA esters are potent activators of the K ATP channel in human pancreatic beta cells. The fact that LC-CoA esters also stimulate K ATP channel activity recorded in the whole-cell configuration, points to the ability of these compounds to have an important modulatory role of human beta-cell electrical activity under both physiological and pathophysiological conditions. [Diabetologia (2004) essential function has been included in the model of glucose-induced insulin secretion. In this model, increases in blood glucose levels lead to metabolism of glucose which generates an increase in the ATP/ADP ratio. The consensus view is that increases in the ATP/ADP ratio promote closure of the beta-cell K ATP channel, thereby depolarizing the cell membrane resulting in opening of voltage-dependent Ca 2+ channels. The subsequent rise in cytoplasmic free Ca 2+ concentration triggers a series of events leading to exocytosis of insulin. Hence, the K ATP channel provides a critical link between glucose metabolism, electrical activity and insulin secretion in the pancreatic beta cell.The most important molecular regulators of K ATP channel activity are believed to be adenine nucleo-ATP-sensitive potassium (K ATP ) channels play a key role in the coupling between cellular metabolism and electrical activity in a wide range of tissues. Since the discovery of these channels in the beta cell [1], their

Successful intraportal islet transplantation normalizes glucose metabolism in diabetic humans. To date, full function is not routinely achieved after islet transplantation in humans, with most grafts being characterized by only partial function. Moreover, the duration of full function is variable and cannot be sufficiently predicted with available methods. In contrast, most grafts retain partial function for a long time. We hypothesized that partial function can restore normal protein and lipid metabolism in diabetic individuals. We studied 45 diabetic patients after islet transplantation. Labeled glucose and leucine were infused to assess whole-body glucose and protein turnover in 1) 6 type 1 diabetic patients with full function after intraportal islet transplantation (FF group; C-peptide > 0.6 nmol/l; daily insulin dosage 0.03 ± 0.02 U · kg -1 body wt · day -1 ; fasting plasma glucose < 7.7 mmol/l; HbA 1c ≤ 6.5%), 2) 17 patients with partial function (PF group; C-peptide > 0.16 nmol/l; insulin dosage < 0.4 U · kg -1 body wt · day -1 ), 3) 9 patients with no function (NF group; C-peptide < 0.16 nmol/l; insulin dosage > 0.4 U · kg -1 body wt · day -1 ), and 4) 6 patients with chronic uveitis as control subjects (CU group). Hepatic albumin synthesis was assessed in an additional five PF and five healthy volunteers by means of a primed-continuous infusion of [3,3,3-2 H 3 ]leucine. The insulin requirement was 97% lower than pretransplant levels for the FF group and 57% lower than pretransplant levels for the PF group. In the basal state, the PF group had a plasma glucose concentration slightly higher than that of the FF (P = 0.249) and CU groups (P = 0.08), but was improved with respect to the NF group (P < 0.01). Plasma leucine (101.1 ± 5.9 µmol/l) and branched-chain amino acids (337.6 ± 16.6 µmol/l) were similar in the PF, FF, and CU groups, and significantly lower than in the NF group (P < 0.01). During insulin infusion, the metabolic clearance rate of glucose was defective in the NF group versus in the other groups (P < 0.01). Both the basal and insulin-stimulated proteolytic and proteosynthetic rates were comparable in the PF, FF, and CU groups, but significantly higher in the NF group (P = 0.05). In addition, the PF group had a normal hepatic albumin synthesis. Plasma free fatty acid concentrations in the PF and FF groups were similar to those of the CU group, but the NF group showed a reduced insulin-dependent suppression during the clamp. We concluded that the restoration of ~60% of endogenous insulin secretion is capable of normalizing the alterations of protein and lipid metabolism in type 1 diabetic kidney recipients, notwithstanding chronic immunosuppressive therapy. The results of the present study indicate that "success" of islet transplantation may be best defined by a number of metabolic criteria, not just glucose concentration/metabolism alone. Diabetes 50:277-282, 2001

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Finally, the concept of islet cell or stem cell transplantation is most attractive, as it offers many perspectives: islet cell availability could become unlimited and islet or stem cells my be transplanted without life-long immunosuppressive treatment of the recipient, just to mention two of them.

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