[Polyuropolydipsic syndromes]

PROGNOSIS

Intracellular dehydration is the major risk in case of a polyuropolydipsic syndrome. Excepting osmotic polyuria, prognosis depends on a possibly progressive functional anomaly of the hypothalamopituitary axis.

PATHOPHYSIOLOGY

Polyuropolydipsia occurs when antidiuretic hormone (ADH) secretion is absent (central diabetes insipidis), the kidney does not respond to ADH (nephrogenic diabetes insipidus) or in case of physiological inhibition of ADH secretion (primary polydipsia).

EXPLORATION

Dynamic explorations are associated with radioimmunoassay of ADH. They are particularly useful in case of atypical diabetes insipidus and include the water restriction test and a study of the sensitivity to exogenous ADH (dDAVP). The results orient the etiologic diagnosis and allow an evaluation of the fluid intake required as a function of the maximal concentrating capacity of the kidneys.

TREATMENT OF CENTRAL DIABETES INSIPIDUS

Treatment is based on ADH analogs (dDAVP). The aim is to obtain a constant antidiuretic effect without hyponatremia or escape. In case of partial central diabetes insipidus, a non-hormone treatment using compounds which increase vasopressin release or its effect on the kidney can be proposed.

A new syndrome of liver iron overload with normal transferrin saturation

BACKGROUND

We investigated patients who had unexplained hepatic iron overload and normal transferrin saturation.

METHODS

65 patients with a median liver iron concentration of 65 mumol/g dry weight of liver (normal < 36 mumol/g), hyperferritinaemia (566 micrograms/L; normal < 400 micrograms/L), and normal transferrin saturations (32%) were compared with genetic haemochromatosis (GH) controls including homozygous (matched for sex and serum ferritin concentration) and heterozygous individuals. Relatives of patients who had ratios of liver iron concentration to age greater than 1.9 were also studied.

FINDINGS

The 65 patients were significantly older and had significantly less hepatic iron overload than individuals with genetic haemochromatosis. The frequency of HLA-A3 antigen was significantly lower in these patients than in individuals with homozygous (p < 0.0001) or heterozygous (p < 0.0002) GH. Five HLA-identical siblings of the patients had normal serum ferritin concentrations. Most of the patients (95%) had one or more of the following conditions; obesity, hyperlipidaemia, abnormal glucose metabolism, or hypertension.

INTERPRETATION

We have found a new non-HLA-linked iron-overload syndrome which suggests a link between iron excess and metabolic disorders. The current diagnostic criteria for genetic haemochromatosis should be reviewed.

[Importance of atrioventricular synchrony in hypertrophic obstructive cardiomyopathy treated by cardiac pacing]

This study was undertaken to evaluate the effect of permanent dual-chamber cardiac pacing in hypertrophic obstructive cardiomyopathy resistant to medication, paying particular attention to atrioventricular synchrony. Sixteen patients, mean age 59 +/- 13 years (range 36 to 80 years) were divided into two groups after in initial catheter study performed under temporary VDD pacing between March 1990 and April 1993. In group I (n = 11), the gradient was decreased by more than 50% whereas in group II (n = 5), the gradient was unchanged or reduced by less than 50%. The reduction of the gradient was immediately significant in group I, the mean value falling from 104 +/- 33 mmHg (range 60 to 170 mmHg) to 25 +/- 13 mmHg (range 10 to 60 mmHg) (p < 0.0001). In group II, the gradient only decreased initially from 132 +/- 13 mmHg (range 120 to 150 mmHg) to 88 +/- 25 mmHg (range 50 to 130 mmHg) (p < 0.003) but improved atrioventricular synchrony, obtained secondarily either by pharmacological prolongation of the PR interval (association of betablocker and verapamil) or by ablation of the atrioventricular junction, improved the haemodynamic benefits. The residual gradient recorded on the 7th day was only 26 +/- 15 mmHg (range 10 to 50 mmHg) (p < 0.0001). The comparison of the two populations showed that the mean PR interval was shorter in group II (p < 0.016) and the mean value of the optimal AV Delay (the longest AV Delay with complete ventricular capture) was also lower (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Defective cytokine expression but adult-type T-cell receptor, CD8, and p56lck modulation in CD3- or CD2-activated T cells from neonates

Expression of IL-2, interferon-gamma, and IL-3 mRNA and proteins was investigated in peripheral blood mononuclear cells from cord blood after activation with phytohemagglutinin, CD2, or CD3 MAb. The results showed that interferon-gamma and IL-3 expression was decreased in cord peripheral blood mononuclear cells when compared with expression observed in adult peripheral blood mononuclear cells, irrespective of the stimulation used. In addition, in newborn cells a defect in IL-2 secretion and mRNA expression was observed in response to CD2 or CD3 MAb but not in response to phytohemagglutinin-mediated activation. We further analyzed the modulation of nonlymphokine genes under the same protocol of stimulations. The results indicate that in newborn cells, despite a reduced lymphokine expression observed after CD2 or CD3 MAb activation, the up-regulation of the T-cell receptor, CD8, and p56lck was similar to that found in adult cells, as was also found after phytohemagglutinin activation of both types of cells. These data are in favor of a deficient T-cell responsiveness to CD2 or CD3 MAb in newborn cells. This impairment of the T-cell response appears to selectively affect lymphokine gene expression because the modulation of other genes also implicated in T cell activation is not altered.

Vitamin D metabolism by alveolar immune cells in tuberculosis: correlation with calcium metabolism and clinical manifestations

The aim of this study was to investigate the relationship between the pulmonary vitamin D metabolism in tuberculosis and the calcium metabolism abnormalities and other clinical characteristics of the disease. The metabolism of 25-hydroxyvitamin D3 (25(OH)D3) by alveolar immune cells recovered by bronchoalveolar lavage (BAL) was evaluated in parallel to the results of calcium metabolism, 25(OH) D and 1,25 dihydroxyvitamin D (1,25(OH)2D) plasma levels and other clinical parameters obtained in 14 tuberculosis patients. Whilst predominant metabolites produced by lavage cells in patients and controls were 5(E)--and 5(Z) -19-nor-10-oxo-25(OH)D3, 1,25(OH)2D3 was produced by cells from all tuberculosis patients but not by cells from controls. Calcium metabolism abnormalities were observed in only some patients, but the production of 1,25 (OH)2D3 by lavage cells was found to correlate both with 1,25(OH)2D levels (r = 0.67) and post-load urinary calcium excretion (r = 0.59). 1,25(OH)2D3 production by lavage cells was increased in patients of black origin, and those presenting with hilar adenopathy without pulmonary infiltrates, and was correlated with the number of lymphocytes recovered by lavage (r = 0.87). We conclude that 1,25(OH)2D3 production by alveolar immune cells makes a major contribution to the abnormalities in calcium metabolism seen in tuberculosis patients, and may be partly dependent on the clinical characteristics evaluated here.

Vitamin D metabolism by alveolar immune cells in tuberculosis: correlation with calcium metabolism and clinical manifestations

The aim of this study was to investigate the relationship between the pulmonary vitamin D metabolism in tuberculosis and the calcium metabolism abnormalities and other clinical characteristics of the disease. The metabolism of 25-hydroxyvitamin D3 (25(OH)D3) by alveolar immune cells recovered by bronchoalveolar lavage (BAL) was evaluated in parallel to the results of calcium metabolism, 25(OH) D and 1,25 dihydroxyvitamin D (1,25(OH)2D) plasma levels and other clinical parameters obtained in 14 tuberculosis patients. Whilst predominant metabolites produced by lavage cells in patients and controls were 5(E)--and 5(Z) -19-nor-10-oxo-25(OH)D3, 1,25(OH)2D3 was produced by cells from all tuberculosis patients but not by cells from controls. Calcium metabolism abnormalities were observed in only some patients, but the production of 1,25 (OH)2D3 by lavage cells was found to correlate both with 1,25(OH)2D levels (r = 0.67) and post-load urinary calcium excretion (r = 0.59). 1,25(OH)2D3 production by lavage cells was increased in patients of black origin, and those presenting with hilar adenopathy without pulmonary infiltrates, and was correlated with the number of lymphocytes recovered by lavage (r = 0.87). We conclude that 1,25(OH)2D3 production by alveolar immune cells makes a major contribution to the abnormalities in calcium metabolism seen in tuberculosis patients, and may be partly dependent on the clinical characteristics evaluated here.

LDL sialic acid content in patients with coronary artery disease

Low density lipoproteins (LDL) are considered to be the most atherogenic of lipoproteins. These LDL can be modified and oxidative modifications are now well known. In addition, other atherogenic modifications of LDL exist, such as desialylation. In the present study sialic acid content was determined in LDL preparations obtained from patients with coronary artery disease (CAD+) and compared with that of healthy subjects and patients without coronary heart disease (CAD-). The sialic acid concentration was found to be statistically lower (P < 0.05) in the LDL of CAD+ patients (11.6 +/- 2.7 micrograms/mg of protein) than in the LDL of controls (16.5 +/- 5.6 micrograms/mg of protein) or in the LDL of CAD- patients (15.3 +/- 3.8 micrograms/mg of protein). In subgroups of CAD+ patients divided according to the severity of the disease, no statistically significant difference was observed in LDL sialic acid content. This work confirms the presence of desialylated LDL in the sera of patients with atheroma.

Role of the renin-angiotensin system on the renal functional reserve in renal transplant recipients

To determine the renal functional reserve in renal transplant recipients, we measured the glomerular filtration rate by inulin clearance and the renal plasma flow by PAH clearance before and during an amino acid infusion (Totamine, 6 to 8 mg/kg/min for 90 to 120 min) in 18 transplanted patients with stable renal function. To test the role of the renin-angiotensin system on the renal functional reserve, we performed a crossover placebo-controlled randomized trial of acute blockade of the renin-angiotensin system by injection of perindoprilat (2 mg i.v.), an inhibitor of angiotensin converting enzyme before amino acid infusion, each patient being studied twice at seven day intervals. Amino acid infusion induced a time-dependent increase in the glomerular filtration rate (P = 0.04), whether or not the renin-angiotensin system was blocked. Maximal increases were from 49.1 +/- 4.1 to 58.9 +/- 5.4, mean +/- SE (18.5%), in control conditions and from 52.4 +/- 5.6 to 62.1 +/- 5.5 ml/min/1.73 m2 (19.7%) after perindoprilat. The increase in glomerular filtration rate was less pronounced in patients taking cyclosporin A than in patients treated with steroid and azathioprine. Amino acid infusion also induced a significant and time-dependent increase (15.2 to 20.2%) in the renal plasma flow (P < 0.01) whether or not perindoprilat had been given. Furthermore, perindoprilat alone increased renal plasma flow by 13.6%, and this effect seemed additive with that of amino acids. Perindoprilat injection decreased filtration fraction (from 0.20 +/- 0.01 to 0.19 +/- 0.01). This parameter returned to basal values after amino acid infusion (0.20 +/- 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective study of patients with CT detected pallidal calcifications

In a prospective study pallidal calcification was detected in 30 of 1478 (2%) adult patients, on CT brain scans. In 8 cases (26%), the calcifications were detected either years after, or during the course of, conditions known to cause basal ganglia calcification, including AIDS in four cases. Eight patients (three with AIDS) had disturbances of calcium and phosphorus metabolism. It was concluded that: a) pallidal calcification is not uncommon and aetiological factors may be recognised more often than previously reported; b) AIDS is emerging as a significant cause of pallidal calcification in young adults, and c) in AIDS and other conditions, abnormal calcium and phosphate metabolism may act in conjunction with local vascular changes.

[Diuretics, potassium depletion and ventricular hyperexcitability]

This prospective randomized study involved 28 patients with moderate essential hypertension who for one year, took either hydrochlorothiazide [Esidrex (E) 25-50 mg per day] or a combination of altizide 15 mg--aldactone 25 mg [Aldactazine (A) 1 or 2 tablets per day] without potassium supplements. Blood pressure, plasma potassium, exchangeable potassium, ventricular premature contractions measured by Holter and plasma magnesium were monitored. Blood pressure was brought to normal in both treatment groups (p < 0.001). Plasma potassium fell by 0.19 mmol/l with A (NS) and 0.35 mmol/l (p < 0.01) with E. Changes in potassium pool were not significant. There was a non-significant reduction in the number of ventricular premature contractions in both groups. There was no correlation between the few cases of frank hypokaliema, fall in potassium pool and complex ventricular premature contractions. A review of the literature offers no solid arguments suggestive of significant potassium risk associated with these diuretics. Any such risk can be eliminated by the use of low doses, combined if necessary with a potassium-sparer or a hypotensive agent of another group.

Retrieval of a lost coronary stent from the descending aorta using a PTCA balloon and biopsy forceps

We report a case of unsuccessful stenting of a right coronary artery after acute dissection during percutaneous transluminal coronary angioplasty (PTCA). The stent was lost in the descending aorta and we used an original technique to remove it from the arterial bed by using both a very low profile balloon and a 6F bioptome.