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The clinical classification of malignant hypercalcaemias according to the presence or absence of bone lesions no longer corresponds to the physiopathology of these hypercalcaemias as it is known today. Both focal osteolysis and humoral hypercalcaemia involve a number of substances, such as prostaglandins, cytokines, growth factors, PTH-rp and calcitriol, the action of which is neither specific nor single. A knowledge of their role in the pathogenesis of hypercalcaemia should lead to the development of antagonists for therapeutic purpose and to a better understanding of their individual physiological effects, since some of these mediators are present in non-tumoral tissues. In humoral hypercalcaemia, PTH-rp seems to play a major role on kidneys and bones.

The characteristics of PTH secretion, which have been extensively studied in vitro with dispersed cells of normal and abnormal parathyroid glands, remain poorly studied in vivo. We performed ethylenediamine tetraacetate (EDTA) intravenous infusions in 12 normal subjects and 5 patients with hypercalcemia (serum ionized calcium between 2.72 and 2.89 mEq/l) and surgically proven primary hyperparathyroidism (PHPT) to establish the relationship between nephrogenous cyclic AMP (NcAMP) used as an index of PTH secretion and serum ionized calcium. We determined the maximal NcAMP taken as an index of maximal secretory rate for PTH, the set point and sensitivity of parathyroid cells for calcium. In normal subjects, mean values (+/- SD) were 4.04 +/- 0.47 nmol/dl glomerular filtrate (GF) for maximal NcAMP, 2.23 +/- 0.04 mEq/l for set point, and -250 +/- 58 for sensitivity when NcAMP was expressed in percent of maximal value and serum calcium in mEq/l. In patients with PHPT, the differences between maximal and basal values of NcAMP represented 50% or more of maximal NcAMP, indicating that PTH secretion was suppressible. Sensitivity values were within normal limits in all patients. Calculated set point values were abnormally elevated (between 2.64 and 2.83 mEq/l) in all patients. Maximal NcAMP values ranged from low to normal (2.77 nmol/dl GF) to abnormally high (6.64 nmol/dl GF), and a positive linear correlation was observed with parathyroid cell mass. Basal serum calcium concentrations were not correlated with either parathyroid cell mass or maximal NcAMP values, and were close to calculated set point values for each patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Unlabelled: The aim of this study was to test the self-blood pressure (Self-BP) measurement device Copal UA-251 (Philips). This device uses auscultatory method for BP measurement. It was compared to reference methods: intraarterial and Hawksley Random Zero in 38 patients, selected in two groups: group RO (n = 18), compared Copal to Random Zero. 20 simultaneous measurements were recorded, with devices inversion at eleventh BP measurement, in 18 treated or untreated hypertensive patients. Group IA (n = 20) included 20 patients and compared Copal to intra-aortic measurement. Three simultaneous measurements were recorded, before a coronarography was performed, in 20 normo or hypertensive patients., Results: (Table: see text). 1) A significant difference was recorded for SBP evaluated by Copal versus RO and for DBP measured by Copal versus IA. 2) A significant correlation was assessed between the different methods of measurement. 3) Differences between couples of RO-Copal values are not correlated to BP level, neither for SBP (r = 0.07), nor DBP (r = 0.05). Same results occur for IA-Copal values (SBP: r = 0.36, DBP: r = 0.30). 4) No order effect was found; no discrepancy between arms occurred in BP measurement., Conclusion: comparing intraaortic measure, Copal is efficient for SBP measurement, but overestimate DBP. Compared to R0, Copal overestimates SBP, but is efficient for DBP measurement. Regarding these results, a self-BP measurement is possible with this device.

Arm girth and circumference often leads to difficulties in Blood Pressure (BP) measurement in obese patients. In order to assess the best method of BP measurement, we have compared in a triplicate study, Intra-arterial Pressure (INTRA) to indirect measurements: Mercury Sphygmomanometer (SPH) and oscillometric device Bard Sentron (SEN). SPH and SEN were successively connected to the same cuff (inflatable bladder 14 x 31 cm). Cuff was positioned on contralateral arm to arterial puncture. 19 subjects were studied (18 female); mean age was 51.3 +/- 9 years (extremes: 37-69), mean weight 104 +/- 19 kg (84-147), weight index 40 +/- 4.7 kg/m2 (34-49), and brachial circumference 39 +/- 4 cm (33-47). First out-patient mean blood pressure measurement was 182/104 mmHg (148-264/80-132). Mean SPH BP were 158 +/- 34/91 +/- 3 (98-230, 72-112) and mean INTRA: 171 +/- 37/85 +/- 5 (122-256/56-118). Mean systolic and diastolic differences (S, D, mmHg) were: (Table: see text). 1) SPH systolic BP underestimates HUM systolic BP. 2) Mean SEN measurements are very closed to HUM values. 3) A great intra-individual variability occurs since more than 50 per cent systolic SPH values show discrepancy of more than 10 mmHg for systolic and diastolic HUM BP; the same discrepancies occur for SEN vs HUM. 4) Differences between couples of values (HUM-SEN, HUM-SPH) are not correlated to BP level, neither for systolic nor for diastolic BP. 5) No significant correlation occurs when BP deltas are compared to weight index or arm circumference.(ABSTRACT TRUNCATED AT 250 WORDS)