Renal metabolism of uric acid in type I insulin-dependent diabetic patients: relation to metabolic compensation.

Patients with insulin-dependent diabetes mellitus and poor glycemic control show hypouricemia with hyperuricosuria. In the present study, we have evaluated whether a good glycemic control influences the renal handling of uric acid. Sixteen patients (8 male, mean age 22.4 +/- 7.2 years) were studied under two situations, poor glycemic control (glycemia > 11 mmol/L and HbA1 c > 10%) and good glycemic control (glycemia < 6 mmol/L and HbA1 c < 8.5%). A group of 16 normal subjects served as the control group (8 male, mean age 21.9 +/- 9.1 years). In the poor glycemic control phase, patients showed lower plasma uric acid levels (0.18 +/- 0.06 mmol/L) and higher fractional urinary excretion of uric acid (16.1 +/- 9.3%) than the controls (0.28 +/- 0.06 and 8.2 +/- 1.9%, respectively). When a good glycemic control was reached, plasma uric acid increased (0.22 +/- 0.05), but it was still lower than that of the controls and fractional excretion of UA was normalized. Plasma uric acid was inversely correlated to glycemia (r = -0.34, p < 0.05) and to HbA1 c (r = -0.56, p < 0.0008) and fractional excretion of uric acid was directly correlated to glycemia (r = 0.39, p < 0.03) and HbA1 c (r = 0.73, p < 0.00005). These results indicate that the hypouricemia and hyperuricosuria of insulin-dependent diabetes mellitus is corrected by an adequate glycemic control, suggesting that these alterations are of a functional origin and due to a defective metabolic control.

[Alkaline encrusted cystitis secondary to Proteus mirabilis infection in a HIV infected patient]. / Cistitis alcalina incrustante secundaria a infección por Proteus mirabilis en un paciente VIH.

We described for the first time an alkaline encrusting cystitis in a patient with the acquired immune deficiency. This is an entity characterized by severe dysuria and long standing urinary frequency, alkaline urine and radiographically visible calcification of the urinary bladder. It has been observed in patients with permanent Foley catheter, persistent infections due to microorganisms with urolytic activity, urinary bilharziosis or tuberculosis, or malignant bladder tumors. None of these entities were described and the patient had all conditions for this syndrome.

[Treatment of malignant otitis externa]. / Tratamiento de la otitis externa maligna.

Though rare the malignant otitis externa must be borne in mind because in its precocious diagnosis is based the success of the management. Elderly people, diabetics and immunodepressed are especially exposed. The CAT is basic in order to detect the spreading of the process. The patient being admitted at a Medical center, the antibiotherapy started at once with Ceftazidine, 2 g every 12 hours via i.v. The exeresis of the e.e.ca proves sometimes necessary after control of the infection. This procedure assures the healing and prevent the recurrences some times seen. But when infection disappears owing to the success of the antibiotherapy in 2-3 weeks; the culture for Pseudomonas is negative 3 weeks later; and the previous CAT showed no spreading to the tympanal bone, the surgery must be discarded. The process is considered over when the culture for Pseudomonas aeruginosa is negative, but review of the patients is compulsory at least during half a year.

Interaction between noradrenaline and diltiazem in rat isolated atria.

1. The present study describes the effects of diltiazem (DIL) on noradrenaline (NA) activity in the isolated right atria of the rat. 2. Interactions between DIL and NA showed that DIL significantly shifted the concentration-response curve of NA to the right in a concentration-dependent manner. 3. The antagonist between DIL and NA is not consistent with a competitive antagonist since the slope is significantly lower than the unity. 4. A high calcium solution (4.5 mM) significantly increased the chronotropic effects of noradrenaline. 5. These results suggest that influx of calcium through calcium antagonist sensitive channels may be involved in linking of chronotropic responses to activation of alpha 1-adrenoceptors.

Tulobuterol: a full beta-adrenoceptor agonist or a partial beta-agonist with membrane stabilizing activity?

1. The effects of tulobuterol on the atrial rate was compared with those of isoproterenol, pindolol and propranolol in spontaneously beating isolated right atria of the rat. 2. Isoproterenol markedly increased atrial rate. To the contrary, propranolol, pindolol and tulobuterol decreased atrial frequency. The chronotropic effect of tulobuterol was similar to that of pindolol but lower than that of propranolol. 3. Interactions between tulobuterol and isoproterenol showed that tulobuterol potentiated the chronotropic effect of low concentrations of isoproterenol but reduced the positive chronotropic response to higher concentrations of isoproterenol. 4. These results suggest that tulobuterol is a partial agonist on atrial beta-receptor but also seems to have another action (possibly a membrane stabilizing activity) which reduced the originally induced effect on beta-receptors as a non-competitive antagonist.

Compared efficacy of quinidine, amiodarone and diltiazem on both nomotopic and ectopic automaticity in the rat heart.

The effect of quinidine, amiodarone and diltiazem have been studied on both nomotopic (isolated right atria) and ectopic automaticity (induced by a local injury in the isolated right ventricle) in the rat heart. The efficacy of these three drugs, measured by the corresponding ID25, was diltiazem greater than quinidine greater than amiodarone on atrial rate and amiodarone greater than quinidine greater than diltiazem on ectopic ventricular automaticity. A depression of isolated right atria rate (sinus node function) could be regarded as an adverse effect of the drug tested (toxicity-index). On the other hand, the reduction of ectopic ventricular automaticity by the antiarrhythmic agent is considered as desired effect (effectiveness-index). We conclude that this method might be useful to evaluate the effectiveness-toxicity ratio, as a first experimental step in the development of new antiarrhythmic drugs with a direct action on cardiac tissue.