Dietary Intervention with Oatmeal in Patients with uncontrolled Type 2 Diabetes Mellitus - A Crossover Study.

BACKGROUND: In a pilot study, we evaluated the efficacy of two days of oatmeal on insulin resistance and glucose metabolism and found a marked decrease of insulin requirements. The most important shortcoming of that study was that the interventions were not isocaloric (diabetes adapted diet: 1500 kcal/d vs. oatmeal 1100 kcal/d). To address these drawbacks we designed the OatMeal And Insulin Resistance (OMA-IR) study. METHODS: The study was a randomized, open label crossover dietary intervention study with consecutive inclusion of 15 patients with uncontrolled type 2 diabetes. The intervention comprised two days of oatmeal on days 3 and 4 of a 5 days hospital stay. During the control period, patients received a diabetes mellitus adapted diet only. The primary endpoint was the daily insulin requirement and glycemic control. RESULTS: Upon oatmeal treatment, the required insulin dose could be significantly reduced on the third and fourth day as compared to the second day of inpatient stay (82.0±30.3 and 69.9±29.9IU versus 112±36.2IU;P<0.001). During control treatment, insulin requirement did not change. There were no significant differences in the changes of mean blood glucose or fasting glucose between both treatments. HbA1c was lower four weeks after the oatmeal intervention. CONCLUSION: In this crossover study, two days of oatmeal intervention allowed a highly significant reduction of required daily insulin doses while maintaining adequate metabolic control as compared to a diabetes adapted diet only. The beneficial effects of the intervention might last for several weeks as shown by the lower HbA1c four weeks after the intervention.

Antioxidative treatment reverses imbalances of nitric oxide synthase isoform expression and attenuates tissue-cGMP activation in diabetic rats.

Oxidative stress and impaired bioactivity of vascular nitric oxide (NO) play an important role in the pathogenesis of macro- as well as microangiopathic complications in diabetes mellitus. To determine the cause of this impaired bioactivity, we tested the effect of long-term hyperglycemia and antioxidative treatment on tissue-specific endothelial (e)NOS- and inducible (i)NOS-expression and the main target of NO action, cGMP, in diabetic rats. After 4 weeks of hyperglycemia, eNOS-mRNA expression was significantly down-regulated in all tissues tested. In contrast, iNOS-mRNA was significantly up-regulated and tissue generation of cGMP significantly increased. Treatment with alpha-lipoicacid reversed changes of NOS-isoform expression as well as cGMP-concentration without changing blood glucose levels. In addition, oxidative stress significantly decreased in diabetic rats treated with alpha-lipoicacid. Together, diabetes regulates NOS-isoforms differentially by down-regulating eNOS and up-regulating iNOS. In addition, our data suggest that the cause of impaired endothelial vasodilatation in experimental diabetes is not degradation or inactivation of NO. On the contrary, these results support the concept of decreased reactivity of the vascular smooth muscle to NO or increased NO activity as a possible vascular damaging agent, e.g., by inducing apoptosis in vascular cells. Furthermore, our data show that antioxidative treatment is capable of reversing changes in the NO-cGMP system and may therefore be an important therapeutic option for preventing vascular damage in diabetes mellitus.

Macrophage migration inhibitory factor and development of type-1 diabetes in non-obese diabetic mice.

AIMS/HYPOTHESIS: T-cell activation by specific antigen has been found to increase macrophage migration inhibitory factor (MIF) expression, indicating its role as an important feature of T-cell activation in vitro and in vivo. To date, the potential role of MIF in the development of autoimmune-mediated diabetes mellitus has not been studied. METHODS: MIF-mRNA expression in splenic lymphocytes of spontaneously diabetic non-obese diabetic (NOD) mice (n=6), cyclophosphamide-treated NOD mice (n=6), 14-day-old non-diabetic NOD mice (n=7) and C57/Bl6 control mice (n=6) was monitored using an internally standardised competitive reverse transcription-polymerase chain reaction, and the MIF-protein levels were determined using Western blot analysis. In addition, the impact of intraperitoneally administered recombinant MIF-protein treatment on diabetes incidence in NOD mice was evaluated. RESULTS: MIF-mRNA expression was markedly increased in splenic lymphocytes of spontaneously diabetic NOD mice as well as in 8-week-old NOD mice treated with cyclophosphamide compared with 2-week-old non-diabetic NOD and healthy C57BL/6 control mice. Western blot analyses showed decreased lymphocytic MIF-protein content in diabetic as well as in cyclophosphamide-treated animals compared with 2-week-old non-diabetic NOD and healthy C57BL/6 mice, probably as a consequence of increased protein secretion. Furthermore, treatment of NOD mice with recombinant MIF-protein at 25 microg twice a week, from age 6 to 11 weeks, led to an increased diabetes incidence (86%; n=7) compared with untreated control groups (55%; n=20) at week 34. CONCLUSIONS/INTERPRETATION: In this study, we report for the first time that MIF-mRNA expression in splenic lymphocytes is up-regulated during development of cell-mediated diabetes in non-NOD mice. The data of our preliminary study suggest a possible role of MIF in autoimmune-inflammatory events, such as type-1 diabetes and also that anti-MIF therapeutic strategy might serve to attenuate autoimmune processes.

Polymerase chain reaction in the detection of tumor cells: new approaches in diagnosis and follow-up of patients with thyroid cancer.

Thyroid cancers are the most common endocrine malignancies and are being diagnosed with increasing frequency. In addition to other measures, diagnosis is based on fine-needle aspiration cytology examination. Recently, new assays using reverse transcription-polymerase chain reaction (PCR) are being tested to improve sensitivity and specificity of primary diagnosis and detection of recurrent thyroid cancer. In the preoperative diagnosis of thyroid cancer, several tissue- and/or tumor-specific mRNA have been described and in several cases, a higher sensitivity and specificity could be achieved using molecular techniques compared to conventional methods. In the postoperative follow-up of patients with thyroid cancer, conflicting data have been published and the use of PCR techniques revealed several problems of the molecular approach, which are based on some technical as well as biologic limitations. Despite these problems, which are discussed in detail in this review, molecular techniques may nevertheless improve the sensitivity and accuracy of fine-needle aspiration of thyroid nodules, fine-needle aspiration of metastases, and detection of recurrent disease in peripheral blood samples.

Quantification of Constitutive Endothelial and Inducible Nitric Oxide Synthase mRNA by Competitive Reverse Transcription-polymerase Chain Reaction.

Nitric oxide (NO) participates in the general homeostatic control of the vasculature, and it is involved in the process of vascular remodelling. NO in particular inhibits the proliferation of vascular smooth muscle cells and has been shown to possess antiatherogenic properties. Two important molecules control NO synthesis, namely constitutive endothelial (ecNOS) and inducible (iNOS) nitric oxide synthase. To investigate the regulation of the ecNOS and iNOS mRNA expression in various tissues, we describe the design and validation of a reliable and efficient competitive RT-PCR approach for quantification of ecNOS and iNOS mRNA in rat tissue. Prior to reverse transcription, the total RNA was supplemented with internal standard RNA-competitors, which were constructed by a modified site-directed mutagenesis followed by in vitro transcription using T7-polymerase. This technique allows the easy and fast (within a single day) construction of an internal, recombinant RNA-fragment without the use of cloning techniques. Only two additional "linker" primers containing the sequence of T7-promoter, the primers used for the wild type of ecNOS and iNOS mRNA and the primers of a spacer gene are needed. In addition, all steps of the procedure can be streamlined by convenient commercially available kits. We conclude that the described technique is a valid and reliable method for the absolute quantification of small amounts of specific mRNA.