Fundamentals about onset and progressive disease character of type 2 diabetes mellitus

ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.     

A persisting secular trend for body measurements in Dutch children. The Oosterwolde 11 study

To investigate whether the secular trend for growth in Dutch children still exists, the Oosterwolde I study of 1980 was repeated in 1989. A persisting secular trend was visible for height while the z scores of body proportions show no change during the past 10 years, which suggests that there is no change in the timing of puberty.     

Cerebrospinal fluid neuropeptides in dementia.

Cerebrospinal fluid concentrations of corticotropin-releasing hormone (CRH), thyrotropin-releasing hormone (TRH) and somatostatin (SRIF) were measured in 77 female inpatients with moderate to extreme dementia and in 17 elderly female controls. Both multi-infarct (MID) and Alzheimer-type (SDAT) demented patients had equally elevated CSF CRH and TRH but not SRIF levels as compared with the controls. This elevation was, however, not seen in patients with simple dementia while it was most prominent in those exhibiting marked depressive symptoms. It is concluded that depression rather than dementia itself may be associated with CSF CRH and TRH elevation in elderly patients with cognitive impairment.     

The influence of age, height, and body weight on cerebrospinal fluid amine metabolites and tryptophan in women

Cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5HIAA), homovanillic acid, and tryptophan were measured in 33 depressed, 36 alcoholic, and 32 neurological control female patients selected by strict operational criteria and investigated under controlled circumstances. Plasma total tryptophan was also measured in blood samples taken simultaneously with lumbar punctures. A multivariate regression analysis was done to discover the effect of age, height, and body weight on these four biochemical measures. Only CSF 5HIAA was significantly dependent on the nonspecific patient variables: height, but neither age nor weight, accounted for more than 10% of the variance of 5HIAA. The same analysis was carried out in all three separate patient groups: the relationship between height and CSF 5HIAA was present throughout, and only 2 of 12 correlations proved to be non-homogeneous. To demonstrate the significantly of these clinical parameters a multivariate analysis of covariance was done to eliminate their effect on the four biochemical variables. As a result significant differences emerged in CSF 5HIAA and total plasma tryptophan for some of the patient groups which were not demonstrable without this correction.