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Biomedical subjects

G Coen

Publications and source records attributed to G Coen.

81 records · Page 5Linked to original sources
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Calcitriol per os once, twice or three times a week: effect of different schedules of administration in hemodialysis patients.

Administration of a single dose of 1,25-OH(2)D(3) can lower PTH levels for up to 4 days in chronic hemodialysis patients. Our purpose was to verify the effects of the same weekly dose of calcitriol per os given in one, two or three administrations, to patients on dialysis with secondary hyperparathyroidism. Thirty patients were studied, divided in to three groups each of 10 patients. Calcitriol therapy in group A was given as a single weekly dose of 0.08 microg/kg b.w. In group B the same total weekly dose was divided in two equal doses. In group C the same total weekly dose was divided in three times. Treatment lasted 2 months. After 8 weeks of therapy the fall in intact PTH was statistically significant in each group, respectively with one-way ANOVA: p<0.02 (A); p<0.002 (B); p<0.001 (c). Two-way ANOVA for comparison of PTH % variation among the three groups was statistically significant p<0.003. Significance was due to difference between group A and groups B and C. The present study confirms the efficacy of single dose in suppressing significantly intact PTH. However, when the same weekly dose is divided into two or in three time-spaced administrations, the suppressive effects are definitely increased.

Administration, Oral↗
PubMedDate not supplied

Who are the non-dippers? A better definition via the blood pressure circadian rhythm.

OBJECTIVE: The non-dipping phenomenon (NDP) can be better interpreted when considering that blood pressure (BP) shows a within-day variability which is the expression of a circadian rhythm (CR). PATIENTS AND METHODS: The NDP was investigated at the light of the BP CR by analysing the ambulatory BP monitoring of 298 essential hypertensive patients (EHP), 84 secondary hypertensive patients (SHP), as well as 93 normotensive subjects (NS). According to the rhythmometric validation, the investigated subjects were defined "rhythmic" (R) or "non-rhythmic" (NR). RESULTS: The non-dippers (ND) were found among not only the EHP (14%) and SHP (27%) but also the NS (16%). The percentages of R ND were 9%, 4% and 20%, respectively in EHP, SHP and NS. The R ND were characterized by a nocturnal phase-shift (100% in NS), associated with an amplitude increase (50% in EHP) or a mesor increase (50% in EHP; 100% in SHP) in BP CR. The NR ND were characterized by an amplitude almost negligible (100% in NS) associated with a mesor increase (100% in EHP; 100% in SHP). CONCLUSIONS: The detection of a NDP associated with a rhythmicity suggests that the criterion with which the ND are identified cannot be used for making inferences on the BP CR in HP or NS. The rhythmic characteristics in ND suggest that the rhythmometric analysis is fundamental for identifying the abnormal time structure of BP 24-h values in the presence of the NDP.

Adult↗
PubMedDate not supplied

[Can cardiovascular calcifications be prevented in chronic kidney disease?].

Chronic kidney disease, with special regard to hemodialysis patients, develop frequent and widespread cardiac and vascular calcifications. In the heart calcifications are mainly located in the coronary arteries and in the valvular structures. There is a strict relation between cardiovascular mortality in CKD and the extent of cardiac and vascular calcifications. Therefore it is important to evaluate the causes of extraskeletal calcifications for the evaluation of the possibility of prevention. The importance of hyperphosphatemia, of hypercalcemia and of the increased CAxP product as a cause of cardiac calcification has been clearly underlined. However the mechanism of calcification, initially considered a physico-chemical precipitation, has been investigated with the conclusion that the process is mediated by cellular differentiation and production of factors favoring mineralization in the extracellular milieu. Increased serum phosphate levels are able to induce a transformation of vascular smooth muscle cells into osteoblast-like cells, able to produce factors known to be pro-mineralizing agents in the bone tissue. Further studies have revealed the importance of a number of inhibitors of calcification of cardiovascular structures, like Fetuin-A, MGP, Osteopontin, Osteoprotegerin. Therefore at present the calcification process of vascular tissue is considered to be linked to a balance between inducers and inhibitors of calcium-phosphate deposits. Prevention of cardiac calcifications is at present mainly based of optimal control of serum phosphate and reduction of calcium load through the use of non-calcium containing phosphate binders. Treatment with statins for prevention and treatment of atherosclerosis is also an important means of decreasing the size and number of atherosclerotic plaques, where a portion of the calcification process develops.

Calcinosis↗
PubMedDate not supplied

[Hypoparathyroidism and Addison's disease with moniliasis: report of two cases in childhood (author's transl)].

Two pediatric cases are described presenting a conjunction of Addison's disease and hypoparathyroidism. One of the two cases also exhibits moniliasis of the oral cavity (Whitaker's disease). A full report is given of the symptoms and of the laboratory analyses which have motivated the diagnosis, and of the endocrinological function tests which were intended to confirm the diagnosis. The clinical process and the therapeutic criteria adopted are subsequently reported. A discussion follows focusing on the possible causes of the coexistence of the immunological defect and of the endocrinous deficiencies which are typical of the syndrome. Pathogenetic priority is attributed to the immunological defect which induces a autoimmune lesion of the endocrinous glands concerned.

Addison Disease↗
PubMedDate not supplied

Defective calcium absorption in the proximal small intestine in chronic renal failure: effect of dihydrotachysterol.

Intestinal absorption of calcium was evaluated in 6 uraemic patients and in 7 control subjects by a two isotope technique exploring absorption in the four hours following ingestion of the dose. In the first two hours, calcium absorption in the patients was markedly lower than normal and was corrected by 6-10 day administration of dihydrotachysterol, 0.66 mg per day. The administration of 0.33 mg per day proved less effective. The data indicate the existence of impaired intestinal calcium absorption in chronic renal failure and reversal of the defect after DHT administration. The method of investigation appears to be a valid procedure for the study of calcium malabsorption of CRF and in the evaluation of the effect of vitamin D metabolities and analogs.

Acute Kidney Injury↗