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Endocrinology and Internet
A. S. Alexandrov, N. A. Alexandrov*
Institute of Biophysics, Bulgarian Academy of Sciences - Sofia
*Chemical Faculty, University “Sv. Kliment Ohridski” - Sofia

Abstract
Internet is a worldwide network of computers, connecting million of machines and numerous small computer-nets. This is a review presenting a concise description of the basic Internet idea (definitions, structure, net-support), with emphasis laid on the issue how, and by what means the information of endocrinology is represented in the net. Appendix A submits a list of well known Internet sources (Web sites and newsgroups) described in the article. Appendix B contains an Internet glossary of some common computer terms. The review is based only on web sites in both English and Bulgarian the authors are familiar with.
KEY WORDS: Internet, endocrinology, Web sites.
 
 

Carbohydrate and Lipid Disturbances
in Certain Hypothalamo-hypophyseal 
Diseases. III. Cushing's Syndrome
M. Orbetzova
Clinical Center of Endocrinology and Gerontology, 
Medical University - Sofia 

Abstract
The important implications of glucocorticoids in intermediary metabolism is a universally estabilished fact, and even their name derives from the properties to control blood sugar level in various conditions of the organism by assuming a protective role against hypoglycemia. Glucocorticoids stimulate glycogen synthetase, enhance glycogen deposits in the liver, and decrease the activity of key glycolytic enzymes. Their chief action includes activation of gluconeogenetic enzymes and reduction of glucose transport through cell membranes, as well as tissue glucose uptake and utilization. Glucocorticoids antagonize insulin effects by a mechanism still not well enough clarified. Presumably, glucocorticoid-induced insulin resistance is most likely attributable to post-binding defects. As regards glucocorticoid influence on lipid metabolism, the data available are scanty and conflicting. Their predominant  effect at adipocyte level is enhanced lipolysis resulting in glycerol and nonesterified fatty acids' release.
Cushing's syndrome serves as an endogenous model of chronic glucocorticoid excess associated with insulin resistance and metabolic disorders whose further elucidation will contribute to gain better insight into insulin resistance pathophysiology in general.
KEY WORDS: glucocorticoids, ACTH, Cushing's syndrome, carbohydrate metabolism, diabetes mellitus, lipid metabolism, dyslipidemia. 
 
 

Anthropological Measurements 
in Marfan's Syndrome Patients
V. Todorov, A. Tomova, S. Maximova
Clinical Center of Endocrinology and Gerontology, 
Medical University - Sofia

Abstract
This is a report on five men and two women, presenting the rarely encountered Marfan's syndrome, studied by evaluating a number of anthropometric parameters. In the study group 13 basic anthropometric parameters are assessed and compared to their counterparts in age-matched normal subjects. Analysis of the results points to significantly elevated values in terms of stature, trochanteric height, bihumeral and bitrochanteric diameters, arm length, arm span length, arm span index and foot length among male patients, and stature, arm length and arm span length among female patients. However, in both men and women the stature/trochanteric height and bihumeral/bitrochanteric diameter ratios do not show noteworthy differences. Only the arm length/stature ratio in the patients group is greater. Regardless of the changes in absolute values of the parameters assayed, the correlations between the latter hardly justify to assume a significant disproportion in body development on the ground of the case material being examined.
KEY WORDS: Marfan's syndrome, anthropometric parameters, body proportions.  
 
 
 

Biochemical Bone Turnover 
Markers in Type 1 Diabetes 
Mellitus Patients 
M. Petkova, P. Dukova-Peneva*, M. Boyanov**
Diagnostic and Consultative Center “St. Luka” - Sofia 
*Department of Clinical Laboratory, Hospital “Maitchin Dom” 
**Endocrinology Clinic, Alexandrov's Hospital 
Medical University - Sofia

Abstract 
It is a well established fact that type 1 diabetes mellitus gives rise to osteopenia. It is the purpose of the report to assay the biochemical markers of bone turnover and bone remodelling in type 1 diabetic patients. Fourteen male and 13 female type 1 diabetic patients are studied. The bone turnover markers measured include: serum osteocalcin (OC), serum C-terminal procollagen type I propeptide (PICP), urinary  deoxypyrydinoline (DPD) and hydroxyproline (OH-Pro). Forearm bone mineral density is measured by single x-ray absorptiometry. Mean bone density values are within the range of osteopenia (T-score - 82,5-86,5%). Lower than normal values are found for sOC and PICP, and elevated ones - for urinary Ca2+/Creat. ratio. Urinary OH-Pro excretion is significantly higher in microalbuminuric patients, as compared to normoalbuminuric ones. The obtained results suggest that reduced bone formation is the primary bone metabolism disorder in type 1 diabetes patients. Increased OH-Pro excretion in microalbuminuria is most likely due to fibrogenesis enhancement. Further prospective studies along this line are needed.
KEY WORDS: type 1 diabetes mellitus, forearm bone density, biochemical bone turnover markers.
 
 

Plasma Levels of Endothelin-1 
in Patients with Cushing's Syndrome
G. Kirilov, A. Tomova, L. Dakovska, Ph. Kumanov
Clinical Center of Endocrinology and Gerontology, 
Medical University - Sofia

Abstract 
Over the past decade, numerous experimental and clinical data have been published demonstrating the importance of endothelin as a modulator of hypothalamic-pituitary-adrenal axis function. Its pathophysiological implications are suspected in a number of adrenal disorders, such as: primary hyperaldosteronism, pheocromocytoma and adrenocortical insufficiency. For the first time in this study plasma endothelin-1 (ET-1) concentration is measured in 13 untreated patients with Cushing's syndrome - 8 men and 5 women at mean age 44.2±9.5 y - of which 10 with Cushing disease and 3 with corticosteroma, duely diagnosed. In the patients with Cushing syndrome ET-1 shows a significant 3-fold increase, as compared to healthy controls (n=15): 1.59±0.78 vs 0.46±0.20 fmol/ml at p<0.001. In those presenting corticosteroma ET-1 is insignificantly increased by comparison with Cushing disesase cases (1.84±0.67 vs 1.51±0.83 fmol/ml at p>0.05). In 3 patients dying of severe cardiovascular complications, plasma ET-1 is significantly higher than in the remainder (2.34 ±0.35 fmol/ml at p<0.05. A positive correlation is established between hipercholesterolemia (6.94 ±1.75 mmol/l) and hyperendothelinemia among the patients: r=+0.73, p<0.02. However, there is no correlation between ET-1 level and arterial hypertension (183±37/106±18 mmHg), plasma cortisol levels (16.5±2.7 mg/dl) and urinary cortisol excretion (530.5±263.5 mg/24h).
As clearly shown by the results, the endothelin system in Cushing syndrome is markedly activated. Hyperendothelinemia is most likely implicated in the pathogenesis of accelerated and premature atherosclerosis development in this condition. Plasma ET-1 level in Cushing syndrome along with other biochemical parameters may serve as a marker pointing to endothelial dysfunction and increased cardiovascular risk.
KEY WORDS: diabetes mellitus, endothelin, Cushing syndrome,  endothelial dysfunction.
 
 
 

The Endothelin - an Early Marker 
for Endothelial Dysfunction 
in Insulinresistant States
P. Karatodorova, L. Koeva
Department of Endocrinology and Metabolic Diseases, 
Medical University - Varna

Abstract
Diabetes mellitus is a disease associated with a multitude of metabolic abnormalities which indirectly or directly influence the endothelium of the vascular wall. Most of the late complications of diabetes reflect and result from microvascular dysfunction. Endothelin, as a product of endothelial cells is one of the circulating markers of endothelial dysfunction. Significant and diverse changes in its concentration can be seen in conditions like diabetes and X - syndrome. The present review examines some aspects of the synthesis and biological effects of endothelin as well as its relations to some of the  the crucial metabolic factors in diabetes (blood glucose, plasma lipids, insulin).
KEY WORDS: diabetes mellitus, endothelin, endothelial dysfunction.