Biomedical subjects

Michaela Diamant

Publications and source records attributed to Michaela Diamant.

22 records · Page 2Linked to original sources

PubMed2002

Elevated numbers of tissue-factor exposing microparticles correlate with components of the metabolic syndrome in uncomplicated type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes is associated with accelerated atherosclerosis. Because cell-derived microparticles support coagulation and inflammation, they may be involved in atherogenesis. We characterized circulating microparticles both in patients with uncomplicated, well-regulated type 2 diabetes and in healthy subjects, as well as their relationship with coagulation and metabolic control. METHODS AND RESULTS: Microparticles were isolated from plasma, stained with annexin V, cell-specific monoclonal antibodies (MoAbs) and a MoAb directed against tissue factor (TF), and analyzed by flow cytometry. Microparticle numbers and origin were comparable in the two groups, but the median number of TF-positive microparticles was twice as high in patients than in controls (P=0.018). Patients had higher percentages of TF-positive microparticles from T-helper cells (P=0.045), granulocytes (P=0.004), and platelets (P=0.002). Subpopulations of TF-positive microparticles from platelets and T-helper cells exposed granulocytic markers. Correlations were found between the numbers of various TF-positive microparticle subpopulations and body mass index, fasting plasma glucose and insulin, or tumor necrosis factor-alpha and serum HDL cholesterol. Microparticles from patients generated less thrombin in vitro (P=0.007). Microparticle numbers did not correlate with in vivo coagulation markers prothrombin fragment F(1+2) and thrombin-antithrombin complexes. CONCLUSIONS: TF, possibly of granulocytic origin, is exposed on microparticle subpopulations in asymptomatic patients with well-regulated type 2 diabetes. TF-positive microparticles are associated with components of the metabolic syndrome but not with coagulation. Thus, TF on microparticles may be involved in processes other than coagulation, including transcellular signaling or angiogenesis.

Adult↗

PubMed2002

Does radioiodine therapy have disadvantageous effects in non-iodine accumulating differentiated thyroid carcinoma?

BACKGROUND: Although radioiodine therapy in differentiated thyroid carcinoma without radioiodine accumulation has not been considered harmful, increased thyrotrophin levels during thyroxine withdrawal without the benefit of radiotoxicity as well as the selection of de-differentiated cells may have disadvantageous effects on tumour course. OBJECTIVE: We therefore analysed retrospectively the effects of radioiodine therapy on the course of serum thyroglobulin levels as a tumour marker in patients with progressive residual or metastatic differentiated thyroid carcinoma, with or without radioiodine accumulation on post-therapeutic whole body scintigraphy. PATIENTS AND METHODS: Patients who had undergone radioiodine therapies with sufficient pre- and post-therapy thyroglobulin measurements to allow for regression analysis and not preceded or followed by other treatment modalities within a 1-year interval were selected. All patients had undergone total thyroidectomy and ablative therapy. Thirty-nine patients and radioiodine therapies were included (10 males, 29 females, mean age 57 years), and divided into a negative- (n = 17) and a positive post-therapeutic whole body scintigraphy group (n = 22). Pre- and post-therapeutic thyroglobulin course were analysed using non-linear regression, comparing the difference in the thyroglobulin growth coefficient b1 post- and pre-therapy (delta b1: b1(post-therapy)-b1(pre-therapy)). In addition, absolute post- and pre-therapeutic thyroglobulin levels, radiological follow-up and clinical outcome were also analysed. RESULTS: The two groups were comparable with respect to age, sex, tumour stage, histology and prior therapies. Differences between post- and pre-therapeutic b1 values differed significantly in the positive post-therapeutic whole body scintigraphy group (delta b1: -0.65 microg/l-1 years-1, P < 0.001) but not in the negative post-therapeutic whole body scintigraphy group (delta b1: -0.14). Absolute serum thyroglobulin levels and radiological follow-up revealed a favourable response of radioiodine therapy in the positive whole body scintigraphy group but not in the negative group. Delta b1 was related significantly with clinical outcome as revealed by receiver operator curves (ROC): all patients with a positive delta b1 (n = 8) had an unfavourable outcome (progression or death), whereas from the 31 patients with negative delta b1, 61% had an unfavourable outcome. CONCLUSION: We did not find disadvantageous effects of a single radioiodine therapy on serum thyroglobulin increments in patients with negative post-therapeutic whole body scintigraphy. However, as we did not observe a beneficial effect either, we would not advise the continuation of radioiodine therapy in patients with negative post-therapeutic whole-body scintigraphy, unless a positive response is observed in individual cases.

Biomarkers↗

PubMed2002

Genetically defined pancreatic beta cell failure.

The major subtypes of diabetes mellitus (DM) are complex diseases in which the interactions between genetic susceptibility and metabolic, immunologic and environmental factors ultimately lead to the clinical phenotype. The unraveling of these factors and the study of their contribution to the pathogenesis of DM is a process of unimaginable complexity. As a result, despite the individual differences in DM phenotype, most patients with DM receive treatment according to generalized treatment protocols, only discriminating between Type 1 and Type 2 DM and not related to the individual genetic background of the patients. Nevertheless, in recent years, much progress has been made in the search for genetic factors in DM. As an example, the recognition of monogenetic defects in beta cell function has lead to the definition of novel DM subtypes, which have important implications for the individual therapeutic approach for these patients and the understanding of the etiology of DM.

Animals↗

PubMedDate not supplied

Alanine aminotransferase as a marker of non-alcoholic fatty liver disease in relation to type 2 diabetes mellitus and cardiovascular disease.

For a long time, hepatic steatosis was believed to be a benign condition. Only recently, liver steatosis, also termed non-alcoholic fatty liver disease (NAFLD), has gained much interest. In most cases of NAFLD, a condition regarded as the hepatic component of the metabolic syndrome, the enzyme alanine aminotransferase (ALT) is elevated and consequently has been used as a marker for NAFLD. More recently, several cross-sectional and prospective studies have demonstrated associations of this liver enzyme with features of the metabolic syndrome and type 2 diabetes mellitus. This review discusses the biochemical and metabolic properties of ALT, its applicability as a marker of NAFLD and describes its possible role in the pathogenesis of the metabolic syndrome and type 2 diabetes mellitus and subsequent cardiovascular disease. In addition, treatment strategies to ameliorate NAFLD and the associated risks are discussed.

Adipose Tissue↗