Type II diabetes and its therapy in clinical practice - results from the standardised non-interventional registry SIRTA.

BACKGROUND AND METHODS: Modern antidiabetic therapies should achieve low HbA1c values and avoid hypoglycaemic complications. The registry SIRTA included 1522 patients with type II diabetes mellitus (T2DM) from 306 German medical practices. Patients had an HbA1c > 6.5% under the maximum tolerated metformin dose. If required, they received combination therapy with other antidiabetics according to the guideline of the German Diabetes Society [Deutsche Diabetes Gesellschaft (DDG)] or usual medical practice. Patients were followed up for 6 months. The target criteria included the achievement of HbA1c target values and the emergence of severe hypoglycaemic episodes. RESULTS: Most patients (64.0%) were planned to achieve an HbA1c target < 6.5%, the standard target recommended by the 2009 DDG guideline valid throughout the registry. Primarily to reduce the individual risk for hypoglycaemia, 32.4% of patients had a less strict HbA1c-target of 6.5-7.0%. These targets were achieved by 31.3% and 44.3% of patients, respectively. Combination therapies increased from 45% to 56% over the 6 months registry. Four patients had severe hypoglycaemias (0.26%). CONCLUSIONS: The registry confirms results from other epidemiologic studies on the therapy of T2DM in everyday practice. The treatment strategies applied effectively reduced blood glucose and avoided severe hypoglycaemias. An early therapy of insufficiently controlled patients with T2DM is important, as lower baseline values facilitated achieving HbA1c targets.

Clinical benefit of a short term dietary oatmeal intervention in patients with type 2 diabetes and severe insulin resistance: a pilot study.

AIMS/HYPOTHESIS: To evaluate the potential effectiveness of 'carbohydrate days' as a dietary intervention to overcome insulin resistance in type 2 diabetes. MATERIALS AND METHODS: Patients (n=14) with uncontrolled type 2 diabetes and insulin resistance as defined by a dosage of more than 1 IU/day (*)kg BW were consecutively enrolled in this prospective study. Primary outcomes were daily insulin requirement and mean blood glucose levels which were evaluated before, after, and 4 weeks after the intervention. RESULTS: All patients had a metabolic syndrome, 75% had microvascular and 57.1% macrovascular complications. Hospital setting and diabetes adapted diet alone led to improved glycemic control with a mean blood glucose 158+/-47 mg/dl. Intervention with two days of oatmeal diet further decreased mean blood glucose to 118+/-37 mg/dl (p<0.05). This was associated with a significant reduction of insulin dosage by 42.5% (before: 145+/-68.9 U/d, after 83+/-34.2 U/d, p<0.001) as well as a significant reduction (-26.4%, p<0.01) of serum leptin levels. After the four weeks outpatient period, insulin dosage remained significantly decreased (83+/-20.2 U/kg (*)d, p<0.01). Glycemic control was comparable (mean blood glucose141+/-20.78 mg/dl) to glucose levels within the hospital setting. Adiponectin levels increased significantly by 53.8% (p<0.05). CONCLUSIONS: In this uncontrolled pilot study, hospital admission and diabetes adapted diet followed by oatmeal intervention achieved a approximately 40% reduction of insulin dosage required to achieve controlled glucose levels. This effect was conserved after a 4 week outpatient phase with normal diet.

Tissue and serum levofloxacin concentrations in diabetic foot infection patients.

OBJECTIVES: Levofloxacin has a high bioavailability and a broad antibacterial spectrum which covers the common pathogens found in acute and chronic diabetic foot infections. The purpose of our study was to determine the serum and tissue concentrations of levofloxacin when administered orally in patients with infected diabetic foot ulcers and to compare these values with microbiological findings. PATIENTS AND METHODS: Ten outpatients with diabetes and ulcerations of the lower extremity were included. All patients received oral levofloxacin therapy at a dose of 500 mg once daily. Wound tissue and serum samples were collected and levofloxacin concentrations determined by HPLC with fluorescence detection. Additionally, microbiological cultures were performed from swabs and debrided wound tissue, both before and after treatment. MICs of levofloxacin for all bacterial isolates were determined using the Etest. RESULTS: Following oral treatment with levofloxacin for an average of 10 +/- 3.8 days, all patients received debridement at the affected limbs. The levofloxacin concentrations in necrotic wound tissue were between 2.33-23.23 mg/kg and between 0.12-6.41 mg/L in serum. Tissue-to-serum ratios of levofloxacin concentrations for each patient were >1.0. The MIC values for all 17 initially isolated bacteria were < or = 2 mg/L. In half of our patients, fluoroquinolones were one of the few oral monotherapy options where the spectrum covered all initially isolated pathogens. CONCLUSION: Our data showed good tissue penetration of levofloxacin in diabetic foot ulcers. In combination with adequate surgical debridement, levofloxacin seems well suited to the treatment of skin structure infections of diabetics caused by susceptible organisms.

Detection of thyroid peroxidase mRNA in peripheral blood of patients with malignant and benign thyroid diseases.

The aim of this study was to evaluate thyroid peroxidase (TPO) mRNA expression in peripheral blood of patients with benign and malignant thyroid disease. Included were 120 thyroid cancer patients, 85 patients with goitre or Graves' disease (GD) and 54 healthy volunteers. TPO mRNA expression was analysed in peripheral blood by nested RT-PCR. In cancer patients, RT-PCR results were compared with staging, grading and serum thyroglobulin (TG) measurement. TPO transcripts were detected in 7/10 (70%) patients with known metastases of thyroid cancer and in 39 of 110 (36%) patients without metastases (P<0.05), in 15/44 (34%) patients with goitre, in 17/41 (41%) cases with GD and in 4/54 (7.4%) subjects in the control group (P<0.05, controls vs all patients with thyroid disease). Among cancer patients without metastatic disease, RT-PCR results correlated positively with lymph node status (P=0.05), grading (P=0.01) and elevated serum thyroglobulin levels (P=0.03). This is the largest study investigating the use of the TPO-RT-PCR assay. Positivity in TPO-RT-PCR correlates significantly with metastatic disease in cancer patients and with the presence of thyroid disease in general. To date, TPO-RT-PCR cannot substitute for standard techniques in the diagnosis of local recurrence or metastatic spread in thyroid cancer patients. However, as results of TPO-RT-PCR correlate significantly with lymph node status, grading and serum TG measurements in patients with non-metastatic disease, TPO seems to be an interesting molecular marker to look at in follow-up studies.

Circulating calcitonin and carcinoembryonic antigen m-RNA detected by RT-PCR as tumour markers in medullary thyroid carcinoma.

Detection of local relapse or metastasis in medullary thyroid carcinoma (MTC) continue to pose a major diagnostic challenge. Besides established diagnostic studies such as serum calcitonin (CT) and carcinoembryonic antigen (CEA), molecular detection of circulating tumour cells may be an additional diagnostic tool for the early detection of disease recurrence. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with MTC disease using primers specific for CT and CEA, respectively. CT mRNA was not detectable in peripheral blood of all patients with MTC (n = 11) and all controls (n = 32). CEA mRNA was significantly more often detected patients with MTC (72.7%) than in controls (34.4%; p = 0.038; Fisher exact test). With an example of a patient with MTC and massive tumour mass in the neck we demonstrate the failure of detection of CT mRNA over a period of 6 months, whereas CEA mRNA could be detected in peripheral blood of this patient. As a consequence, CT mRNA detected by RT-PCR in the peripheral blood can not be recommended as a tumour marker in MTC. However, the use of carcinoembryonic mRNA may provide a significant improvement in diagnosis of recurrent disease in MTC.

Fluvastatin therapy improves microcirculation in patients with hyperlipidaemia.

The purpose of this study was to investigate the effect of fluvastatin on the microcirculation of patients with hyperlipidaemia (low-density lipoprotein cholesterol > 160 mg/dL, triglycerides < 350 mg/dl) inadequately controlled by diet. After a dietary run-in of 4 weeks, patients were randomised in a double-blind study to receive fluvastatin 40 mg twice daily (n = 24) or placebo (n = 24) for 12 weeks. The effect on microcirculation was assessed using capillary microscopy and laser Doppler fluxmetry at the nailfold at baseline and at 6 and 12 weeks after initiation of therapy. Capillaroscopy showed that fluvastatin improved microcirculation, i.e. time to peak flow during postocclusive reactive hyperaemia dropped from 19.7 +/- 7.2 s at baseline to 12.3 +/- 9.5 s at week 6 (P < 0.01) and 10.6 +/- 6.5 s at week 12 (P < 0.0001). These results were confirmed using laser Doppler fluxmetry to study microcirculation in thermoregulatory capillaries at the same site. A significant decrease in total and LDL-cholesterol was achieved during fluvastatin therapy. In conclusion, fluvastatin therapy improves microcirculation in nutritive as well as thermoregulatory capillaries in hypercholesterolaemic patients within 6 weeks.

Effects of alpha-lipoic acid on microcirculation in patients with peripheral diabetic neuropathy.

Diabetic polyneuropathy is a serious complication in patients with diabetes mellitus. In addition to the maintenance of a sufficient metabolic control, alpha-lipoic acid (ALA) (Thioctacid, Asta Medica) is known to have beneficial effects on diabetic polyneuropathy although the exact mechanism by which ALA exerts its effect is unknown. In order to study the effect of ALA on microcirculation in patients with diabetes mellitus and peripheral neuropathy one group of patients (4 female, 4 male, age 60+/-3 years, diabetes duration 19+/-4 years, BMI 24.8+/-1.3 kg/m2) received 1200 mg ALA orally per day over 6 weeks (trial 1). A second group of patients (5 female, 4 male, age 65+/-3 years, diabetes duration 14+/-4 years, BMI 23.6+/-0.7 kg/m2) was studied before and after they had received 600 mg ALA or placebo intravenously over 15 minutes in order to investigate whether ALA has an acute effect on microcirculation (trial 2). Patients were investigated by nailfold video-capillaroscopy. Capillary blood cell velocity was examined at rest and during postreactive hyperemia (occlusion of the wrist for 2 minutes, 200 mmHg) which is a parameter of the perfusion reserve on demand. The oral therapy with ALA resulted in a significant decrease in the time to peak capillary blood cell velocity (tpCBV) during postocclusive hyperemia (trial 1: 12.6+/-3.1 vs 35.4+/-10.9 s, p<0.05). The infusion of ALA also decreased the tpCBV in patients with diabetic neuropathy (trial 2: before: 20.8+/-4,5, ALA: 11.74+/-4.4, placebo: 21.9-5.0 s, p<0.05 ALA vs both placebo and before infusions) indicating that ALA has an acute effect on microcirculation. Capillary blood cell velocity at rest (rCBV), hemodynamic parameters, hemoglobinA1c and local skin temperature remained unchanged in both studies. These results demonstrate that in patients with diabetic polyneuropathy ALA improves microcirculation as indicated by an increased perfusion reserve on demand. The observed effects are apparently acute effects. With the restriction of the pilot character of this investigation the findings support the assumption that ALA might exert its beneficial effects at least partially by improving microcirculation which is likely to occur also at the level of the vasa nervorum.

Molecular detection of thyroglobulin mRNA transcripts in peripheral blood of patients with thyroid disease by RT-PCR.

The sensitive detection of circulating tumour cells in patients with differentiated thyroid cancer may precede the detection of relapse by other diagnostic studies--such as serum thyroglobulin-and thus may have important therapeutic and prognostic implications. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with thyroid disease using two different RT-PCR sensitivities. Additionally, tissue specificity of TG mRNA-expression was determined using RNA extracts from 27 different human tissues. The lower limit of detection was 50-100 TG mRNA producing cells/ml blood using a 'normal' RT-PCR sensitivity and 10-20 cells/ml blood using a 'high' sensitivity. With the normal sensitivity TG mRNA was detected in 9/13 patients with thyroid cancer and metastasis, 63/137 patients with a history of thyroid cancer and no metastasis, 21/85 with non-malignant thyroid disease and 9/50 controls. With the high sensitivity TG mRNA was detected in 11/13 patients with thyroid cancer and metastasis, 111/137 patients with a history of thyroid cancer and no metastasis, 61/85 with non-malignant thyroid disease and 41/50 controls. Interestingly, using the normal RT-PCR sensitivity TG mRNA transcripts are specific for thyroid tissue and detectable in the peripheral blood of controls and patients with thyroid disease, which correlates with a diagnosis of metastasized thyroid cancer. However, with a high RT-PCR sensitivity, TG mRNA expression was found not to be specific for thyroid tissue and was not correlated with a diagnosis of thyroid cancer in patients. As a consequence, to date TG mRNA detected by RT-PCR in the peripheral blood cannot be recommended as a tumour marker superior to TG serum-level.

Evaluation of factors controlling glucose tolerance in patients with HCV infection before and after 4 months therapy with interferon-alpha.

BACKGROUND: Epidemiological data suggest that chronic hepatitis C virus (HCV) infection may contribute to the development of diabetes mellitus. Therapy of HCV infection with recombinant interferon-alpha (r-IFN-alpha) can also impair of glucose metabolism. METHODS: To investigate the impact of HCV infection and the therapy with r-IFN-alpha on glucose metabolism we measured insulin sensitivity, glucose effectiveness, and first and second phase insulin secretion, using the minimal modelling analysis of frequently sampled intravenous glucose tolerance tests in 13 nondiabetic patients with HCV-induced liver disease before and after therapy with r-INF-alpha (6 x 106 U, subcutaneously, three times a week over 4 months). Liver biopsy was performed to evaluate and score liver fibrosis as a marker of HCV-induced cell injury. RESULTS: Insulin sensitivity (r = - 0.59, P < 0.05) and first phase insulin secretion (r = - 0.66, P < 0.03) were negatively related to the fibrosis score. Insulin sensitivity rose from 1.96 (SEM 0.37, n = 8) to 5.69 (SEM 0.99, n = 8) 10-4 min-1 per microU mL-1 (P < 0.01) in responders and from 2.51 (SEM 0.61, n = 5) to 6.95 (SEM 1.99, n = 5) in nonresponders after 4 months r-INF-alpha therapy. Fasting free fatty acids decreased significantly to about 50% (P < 0.01) in patients with and without therapy response after 4 months, whereas first phase insulin secretion did not change. CONCLUSIONS: HCV-induced liver injury is related to the deterioration of insulin sensitivity and first phase insulin response, thus impairing glucose homeostasis in these HCV-infected patients. The administration of r-INF-alpha three times a week over 4 months is not associated with an impairment of glucose homeostasis.

Interferon-alpha improves glucose tolerance in diabetic and non-diabetic patients with HCV-induced liver disease.

This pilot study was initiated to evaluate factors controlling glucose tolerance in patients with hepatitis C virus-induced liver disease before and after therapy with recombinant interferon-alpha (r-INF-alpha). Fifteen patients with histologically and serologically proven hepatitis C infection underwent oral and frequently sampled intravenous glucose tolerance tests (FSIGTT) before and after four months of therapy (6 x 106 U r-INF-alpha, subcutaneously, three times a week). Glucose, insulin and C-peptide data from FSIGTT were analysed using the minimal modeling technique to determine insulin sensitivity, glucose effectiveness and first and second phase insulin secretion. According to the WHO criteria 13 patients, had normal glucose tolerance; diabetes mellitus was diagnosed in 2 patients. In the morning following the last r-INF-alpha injection four months later, insulin sensitivity improved significantly in hepatitis C virus-infected patients with normal glucose tolerance (2.17 +/- 0.37 vs. 6.18 +/- 0.94 10(-4) min(-1) per microU/ml, p < 0.001) and with diabetes mellitus (0.86 to 2.61; 0.46 to 1.06 10(-4) min(-1) per microU/ml). This effect was independent of the extent of fibrosis, virus load before treatment and therapy response. First phase insulin secretion increased in non-diabetic (139.2 +/- 17.1 vs. 200.0 +/- 32.7, p < 0.05) and diabetic patients with HCV infection (55.24 to 118.5; 84.23 to 261.1). Moreover, free fatty acid concentrations in all HCV-infected patients were significantly reduced (0.48 +/- 0.01 vs 0.21 +/- 0.03 mmol/l, p < 0.01). Therapy with recombinant interferon-alpha is associated with an amelioration of glucose tolerance in non-diabetic and diabetic HCV-infected patients.

Chronic selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in rats.

OBJECTIVE/METHODS: In order to investigate whether selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in the rat hindlimb, rats were selectively bred to establish two strains, one with a pronounced hypertriglyceridemia (HT) and the other with normal plasma levels of triglycerides (LT). RESULTS: Carotid arteries and aortae removed from 3, 6, 9 and 12 month old LT- and HT-rats exhibited a normal morphology. However, marked morphological differences were observed between vessels from 18-20 month old HT- and LT-rats. The endothelium-dependent vasodilator acetylcholine (2 to 50 micrograms/kg), administered into the iliac artery, elicited a concentration-dependent increase in hindlimb blood flow which was not different in 3, 6 and 9 month old LT- or HT-rats but was impaired in 12 and 18-20 month old HT-rats. In contrast the endothelium-independent vasodilator sodium nitroprusside enhanced blood flow in both strains to a similar extent. Neither administration of the nitric oxide (NO) synthase (NOS) substrate, L-arginine, nor the NOS inhibitor NGnitro-L-arginine, affected the responsiveness to endothelium-dependent vasodilators in 12 month old HT-rats. These attenuated responses could not be attributed to a decrease in endothelial NOS expression as Western blot analysis revealed identical levels of this enzyme in the aortae and carotid arteries from LT- and HT-rats. Determination of superoxide anion (O2-) formation however, demonstrated a markedly elevated production of O2- in aortae from HT-rats. CONCLUSION: We conclude that chronic selective hypertriglyceridemia, an independent risk factor in the development and progression of atherosclerosis, leads to an endothelial dysfunction which is associated with an increased vascular O2- production and a subsequent decrease in bioavailable NO.

Macrophage and lymphocyte homing in experimental diabetes.

Diabetes mellitus was induced in C57BL/6 mice by multiple low doses of streptozotozin (STZ). By transferring lymphocytes from these diabetic animals to healthy recipient mice insulitis can be induced in healthy recipient mice. On day 21 after the start of STZ-treatment splenic lymphocytes were separated in vitro and stained with the fluorochrom acridine red for adoptive transfer. The recipient mouse had been pretreated with a subdiabetogenic dose of STZ (5 mg/kg) i.p. 24 h prior to the lymphocyte transfer. With in vivo microscopy we measured the lymphocyte adherence to the endothelium of islets of the recipient mouse. After the administration of mAbs directed against LFA-1, ICAM-1, murine VCAM-1, VLA-4, MadCAM or alpha4,beta7-integrin prior to the cell transfer we could demonstrate a significant decrease of donor lymphocyte adherence in islets (P<0.01). The pretreatment of the recipient mice with STZ 24 h before the transfer of lymphocytes might attract macrophages to the islets. Therefore we pretreated the recipients with antibodies to cytokines or silica. mAb IFN-gamma, pAb TNF-alpha, pAb IL-1alpha or silica reduced lymphocyte adherence to islet endothelium significantly (P<0.01). The presented results support the following interpretation: The pretreatment of the recipient mice with the islet specific toxin STZ in subdiabetogenic doses attracts macrophages to the islets. The macrophages release cytokines leading to an increased expression of adhesion molecules on the endothelium of the islets. The consequence is lymphocyte homing selectively to the islets. The cascade of lymphocyte homing is complex and various pairs of adhesion molecules are involved. The discussion on the importance of the single pairs of adhesion molecules is irrelevant, since the cascade of lymphocyte homing can be disturbed by the application of a mAb to any one adhesion molecule involved in the cascade of lymphocyte homing.

In vivo microscopy of murine islets of Langerhans: increased adhesion of transferred lymphocytes to islets depends on macrophage-derived cytokines in a model of organ-specific insulitis.

Environmental factors contribute to the pathogenesis of type 1 diabetes (insulin-dependent diabetes mellitus). Multiple low doses of streptozotocin (MLDS) induce hyperglycaemia and insulitis in mice. Previously we demonstrated that adhesion of lymphocytes to endothelium of islets is only increased when donor animals were diabetic and recipient mice had received 5 mg/kg streptozotocin (STZ). Therefore we used streptozotocin to evaluate the immunological relevance of such an irritation of islets. Lymphocytes, separated from diabetic mice (MLDS), were fluorescently labelled and injected to recipient mice that had received 5 mg/kg STZ. With in vivo microscopy we measured lymphocyte flow and adherence in islets. Expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) in the pancreas was assessed using immunohistochemistry. Very late antigen-4 (VLA-4) and leucocyte function-associated antigen-1 (LFA-1) expression on transferred lymphocytes was measured with flow cytometry. Pretreatment of recipients with antibodies to cytokines or silica reduced lymphocyte adherence to islet endothelium from 2.04% (goat immunoglobulin G; IgG) or 1.82% (rat IgG) to 0.47, 0.58, 0.39 or 0. 19% for monoclonal antibody (mAb) interferon-gamma (IFN-gamma), polyclonal antibody (pAb) tumour necrosis factor-alpha (TNF-alpha), pAb interleukin (IL)-1alpha or silica, respectively. Reduced adhesion was associated with a decreased expression of VCAM-1 and ICAM-1 in islets of treated recipients compared with mice treated with 5 mg/kg STZ alone. In conclusion, pretreatment of recipients with 5 mg/kg STZ leads to an increased expression of adhesion molecules in the islets and lymphocyte adhesion to islet endothelium in vivo, demonstrating an immune response of the islets. Prevention of increased expression of ICAM-1 or VCAM-1 and reduction of lymphocyte adhesion in islets by silica or antibody indicate an involvement of macrophages and macrophage derived cytokines in the generation of this immune response.

Mutations in the apolipoprotein (apo) B-100 receptor-binding region: detection of apo B-100 (Arg3500-->Trp) associated with two new haplotypes and evidence that apo B-100 (Glu3405-->Gln) diminishes receptor-mediated uptake of LDL.

BACKGROUND: Ligand-defective apolipoprotein (apo) B-100 is a major cause of hypercholesterolemia. For many years, apo B-100 (Arg3500-->Gln) has been the only mutation known to cause ligand-defective apo B-100. METHODS: Using temperature gradient gel electrophoresis, we screened 297 unrelated individuals with LDL-cholesterol >1.55 g/L and triglycerides <2.0 g/L for sequence variants of the putative LDL receptor-binding domain of apo B-100. RESULTS: We found apo B-100 (Arg3500-->Gln) in 21 individuals (7.1%). When extrapolated to the general population, this corresponds to the highest prevalence of apo B-100 (Arg3500-->Gln) reported to date. Furthermore, we identified three unrelated carriers (1%) of a silent substitution (CTG-->CTA) affecting the codon for leucine3350, four carriers (1.3%) of apo B-100 (Glu3405-->Gln), and two subjects (0.7%) with apo B-100 (Arg3500-->Trp). apo B-100 (Arg3500-->Trp) was assigned to two different, previously unknown haplotypes. The binding, uptake, and degradation of apo B-100 (Arg3500-->Trp) was lower than that of normal LDL, but higher than with apo B-100 (Arg3500-->Gln), implying that the substitution of Trp3500 for Arg may cause less severe reduction of binding than the substitution of Gln. LDL from individuals heterozygous for apo B-100 (Glu3405-->Gln) bound to LDL receptors at the same rate as normal LDL, but was taken up and degraded at significantly reduced rates, suggesting that domains of apo B-100 involved in binding and uptake do not completely overlap. CONCLUSIONS: In Germany, apo B-100 (Arg3500-->Gln) may be more frequent than previously assumed. Both apo B-100 (Arg3500-->Trp) and apo B-100 (Glu3405-->Gln) may contribute to the phenotype of ligand-defective LDL. These variants will be missed if screening is confined to apo B-100 (Arg3500-->Gln) only.

The effect of alpha-lipoic acid on the neurovascular reflex arc in patients with diabetic neuropathy assessed by capillary microscopy.

Patients with diabetic polyneuropathy are known to have an impaired neurovascular reflex arc compared to healthy controls. This is seen in a delayed decrease in microcirculation of the ipsilateral hand after cooling of the contralateral hand. The aim of this pilot study was to investigate whether intravenous alpha-lipoic acid (ALA) (Thioctacid, Asta Medica) therapy might be able to improve this impaired neurovascular reflex arc in patients with diabetic neuropathy. In addition, clinical effects were evaluated with the aid of the neuropathy symptom score (NSS) and the neuropathy disability score (NDS). Ten patients with diabetes mellitus and polyneuropathy (5 females, 5 males, 2 smokers, 5 IDDM, 5 NIDDM, body mass index 26.1 +/- 1.0 kg/m2, age 58.3 +/- 9.5 years, diabetes duration 15.7 +/- 11.2 years, Hb A1c 6.8 +/- 0.3%) were investigated by nail-fold capillaroscopy after contralateral cooling before and after intravenous therapy with 600 mg alpha-lipoic acid per day over 3 weeks. Cardiac autonomic neuropathy was excluded by beat-to-beat variation analysis. Symptoms of diabetic neuropathy were evaluated before and after therapy with the aid of the NSS and NDS. Capillary blood cell velocity (CBV) of the hand was determined before, during, and for the following 30 min after cooling (3 min at 15 degrees C) of the contralateral hand. Blood pressure, heart rate, and local skin temperature were monitored at 2-min intervals. ALA therapy resulted in a significant improvement of the microcirculatory response to cooling, as seen by an immediate decrease in CBV of 12. 3% (P < 0.02 vs before treatment), which was absent before therapy. Blood pressure, heart rate, and local skin temperature were not different between investigations. There was a significant improvement of the NSS after therapy (5.4 +/- 1.1 vs 8.6 +/- 1.1 points, P < 0.01). These results demonstrate that intravenous therapy with ALA has a positive influence on the impaired neurovascular reflex arc in patients with diabetic neuropathy.

alpha-Lipoic acid treatment decreases serum lactate and pyruvate concentrations and improves glucose effectiveness in lean and obese patients with type 2 diabetes.

OBJECTIVE: We examined the effect of lipoic acid (LA), a cofactor of the pyruvate dehydrogenase complex (PDH), on insulin sensitivity (SI) and glucose effectiveness (SG) and on serum lactate and pyruvate levels after oral glucose tolerance tests (OGTTs) and modified frequently sampled intravenous glucose tolerance tests (FSIGTTs) in lean (n = 10) and obese (n = 10) patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: FSIGTT data were analyzed by minimal modeling technique to determine SI and SG before and after oral treatment (600 mg, twice a day, for 4 weeks). Serum lactate and pyruvate levels of diabetic patients after glucose loading were compared with those of lean (n = 10) and obese (n = 10) healthy control subjects in which SI and SG were also determined from FSIGTT data. RESULTS: Fasting lactate and pyruvate levels were significantly increased in patients with type 2 diabetes. These metabolites did not exceed elevated fasting concentrations after glucose loading in lean patients with type 2 diabetes. However, a twofold increase of lactate and pyruvate levels was measured in obese diabetic patients. LA treatment was associated with increased SG in both diabetic groups (lean 1.28 +/- 0.14 to 1.93 +/- 0.13; obese 1.07 +/- 0.11 to 1.53 +/- 0.08 x 10(-2) min-1, P < 0.05). Higher SI and lower fasting glucose were measured in lean diabetic patients only (P < 0.05). Lactate and pyruvate before and after glucose loading were approximately 45% lower in lean and obese diabetic patients after LA treatment. CONCLUSIONS: Treatment of lean and obese diabetic patients with LA prevents hyperglycemia-induced increments of serum lactate and pyruvate levels and increases SG.

Soluble ICAM-1 reduces leukocyte adhesion to vascular endothelium in ischemia-reperfusion injury in mice.

Ischemia-reperfusion injury is a pathogenic factor in the course of many clinical disorders, such as myocardial infarction, stroke, organ transplantation, burns, and circulatory shock. The extent of ischemia-reperfusion injury is dependent on the number of infiltrating leukocytes. With in vivo microscopy, we evaluated the effect of the recombinant form of soluble murine intercellular adhesion molecule-1 (ICAM-1) on ischemia-reperfusion injury in an animal model. A mesenteric vein was occluded with a clamp for 45 min. During a reperfusion period of 30 min, the number of leukocytes rolling along the endothelium and the number of adherent leukocytes were measured with and without pretreatment with recombinant ICAM-1. The number of leukocytes rolling along the endothelial surface increased more than twofold during postischemic perfusion (P < 0.05). Recombinant ICAM-1 had no effect on leukocyte rolling. In the control group, firm adherence of leukocytes was increased 10-fold. Recombinant ICAM-1 dose dependently reduced firm adhesion to the endothelium in response to prior ischemia. After 30 min, reperfusion pretreatment with recombinant ICAM-1 inhibited leukocyte adherence from 512 +/- 123 to 166 +/- 34 leukocytes/mm2 (P < 0.01). We demonstrate here for the first time that soluble recombinant ICAM-1 is able to reduce leukocyte adherence to mesenteric venules in postischemic reperfusion injury dose dependently. Because soluble ICAM-1 is naturally circulating in human serum, the therapeutic use of soluble recombinant forms of ICAM-1 may represent a physiological way to protect against ischemiareperfusion injury.

Impairment of peroxisomal structure and function in rat liver allograft rejection: prevention by cyclosporine.

BACKGROUND: During allograft rejection, cytokines and lipid mediators contribute to cell injury and organ failure. Peroxisomes play a crucial role in lipid metabolism, including the degradation of lipid mediators by peroxisomal beta-oxidation. Therefore, we investigated the alterations of hepatic peroxisomes after allogeneic rat liver transplantation. METHODS: MHC-incompatible Dark Agouti (RT1a) donor rats and Lewis (RT1(1)) recipient rats were used for allogeneic transplantation. For immunosuppression, a group of these animals received cyclosporine (CsA) intraperitoneally (1 mg/kg body weight per day). Lewis rats were used for isogeneic transplant combination. Ten days after transplantation, livers were investigated using morphometrical methods for determination of peroxisomal diameter and volume density. The activities of peroxisomal catalase (CAT) and acyl-coenzyme A oxidase (AOX) were determined, and the corresponding proteins were evaluated by quantitative immunocytochemistry and immunoblotting. The expressions of mRNAs encoding CAT and AOX were investigated by Northern blotting. RESULTS: The volume density and diameter of peroxisomes were significantly decreased in allogeneic transplanted livers but were unchanged in CsA-treated animals. Both the activities of CAT and AOX and their protein levels were significantly reduced in liver allografts. Moreover, the corresponding mRNA levels of CAT and AOX were decreased significantly in liver allografts, whereas CsA treatment led to an increase of those mRNAs. Isogeneic transplanted livers showed only a slight reduction of the corresponding enzyme values. CONCLUSIONS: Peroxisomes are severely affected both morphologically and functionally after allogeneic liver transplantation. These results suggest that impairment of peroxisomal lipid beta-oxidation could contribute to the pathogenesis of the rejection process by decreased catabolism of lipid mediators involved in the regulation of the inflammatory response. CsA, in addition to its immunosuppressive effects, may contribute to allograft survival by maintenance of those important peroxisomal functions.

The impact of contralateral cooling on skin capillary blood cell velocity in patients with diabetes mellitus.

In healthy volunteers, cooling of the contralateral hand leads to a rapid decrease in the ipsilateral capillary perfusion via a nerval reflex arc. The aim of this study was to investigate whether this reflex arc after contralateral cooling might be altered in patients with diabetes mellitus with and without peripheral neuropathy. Therefore, 12 patients with diabetic neuropathy (4 IDDM, diabetes duration 17.2 +/- 2.9 (SD) years, age 60.8 +/- 4.0 years, HbA1c 6.5 +/- 0.3%) and 12 patients with diabetes mellitus but without neuropathy (6 IDDM, diabetes duration 15.1 +/- 2.7 years, age 55.9 +/- 4.5 years, HbA1c 5.4 +/- 0.1%) were investigated by nailfold capillaroscopy. Twelve healthy volunteers (age 56.8 +/- 3.1 years, HbA1c 4.8 +/- 0.2%) served as controls. Contralateral skin capillary blood cell velocity was determined at rest and during the following 20 min after cooling of the hand (3 min at 15 degreesC). Blood pressure, heart rate and local skin temperature were examined regularly during the investigation. Resting capillary blood cell velocity did not differ between patients and controls. While contralateral cooling resulted in a decrease in capillary blood cell velocity (CBV) in controls (0.29 +/- 0.05 vs. 0.42 +/- 0.05 mm/s, p < 0.03), CBV remained unchanged or was delayed in patients. These results demonstrate that in diabetic patients nerval reflex arcs are impaired. A long-term follow-up in a larger number of patients is required to evaluate whether these findings might serve as a very early diagnostic tool for the diagnosis of developing diabetic neuropathy.

Lymphocyte transfer in streptozotocin-induced diabetes: adhesion of donor cells to islet endothelium.

The interaction between intravenously transferred lymphocytes derived from spleens of multiple low-dose streptozotocin-diabetic mice with islet, exocrine pancreatic, and gastric mucosal endothelium of nondiabetic recipient mice was investigated by in vivo microscopy. Donor lymphocytes were stained with acridine red in vitro. The adoptive transfer of these cells from diabetic donor animals resulted in significantly increased lymphocyte rolling (4.46 +/- 1.32%, P < 0.05) and adhesion (3.86 +/- 1.04%, P < 0.05) in islets of nondiabetic recipients that had been pretreated with a single subdiabetogenic dose of streptozotocin. No increased endothelial interaction was noted in nonpretreated recipients or in experiments with nondiabetic donors. Rolling (1.19 +/- 0.61 to 2.71 +/- 0.62%) and adhesion (0.61 +/- 0.33 to 2.80 +/- 0.97%) of donor lymphocytes were low in exocrine pancreatic and gastric mucosal control tissue. It is concluded that, in this animal model, lymphocytes from diabetic donors interact preferentially with recipient islet endothelium. However, additional stimulation of recipient islet endothelium by exogenous factors is necessary to enable transferred cells to adhere to pancreatic islets.